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Beever AT, Zhuang AY, Murias JM, Aboodarda SJ, MacInnis MJ. Effects of acute simulated altitude on the maximal lactate steady state in humans. Am J Physiol Regul Integr Comp Physiol 2024; 327:R195-R207. [PMID: 38842515 DOI: 10.1152/ajpregu.00065.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/03/2024] [Accepted: 05/17/2024] [Indexed: 06/07/2024]
Abstract
We sought to determine the effects of acute simulated altitude on the maximal lactate steady state (MLSS) and physiological responses to cycling at and 10 W above the MLSS-associated power output (PO) (MLSSp and MLSSp+10, respectively). Eleven (4 females) participants (means [SD]; 28 [4] yr; V̇o2max: 54.3 [6.9] mL·kg-1·min-1) acclimatized to ∼1,100 m performed 30-min constant PO trials in simulated altitudes of 0 m sea level (SL), 1,111 m mild altitude (MILD), and 2,222 m moderate altitude (MOD). MLSSp, defined as the highest PO with stable (<1 mM change) blood lactate concentration ([BLa]) between 10 and 30 min, was significantly lower in MOD (209 [54] W) compared with SL (230 [56] W; P < 0.001) and MILD (225 [58] W; P = 0.001), but MILD and SL were not different (P = 0.12). V̇o2 and V̇co2 decreased at higher simulated altitudes due to lower POs (P < 0.05), but other end-exercise physiological responses (e.g., [BLa], ventilation [V̇e], heart rate [HR]) were not different between conditions at MLSSp or MLSSp + 10 (P > 0.05). At the same absolute intensity (MLSSp for MILD), [BLa], HR, and V̇E and all perceptual variables were exacerbated in MOD compared with SL and MILD (P < 0.05). Maximum voluntary contraction, voluntary activation, and potentiated twitch forces were exacerbated at MLSSp + 10 relative to MLSSp within conditions (P < 0.05); however, condition did not affect performance fatiguability at the same relative or absolute intensity (P > 0.05). As MLSSp decreased in hypoxia, adjustments in PO are needed to ensure the same relative intensity across altitudes, but common indices of exercise intensity may facilitate exercise prescription and monitoring in hypoxia.NEW & NOTEWORTHY This study demonstrates the power output and metabolic rate associated with the maximal lactate steady-state (MLSS) decline in response to simulated altitude; however, common indices of exercise intensity remained unchanged when cycling was performed at the work rate associated with MLSS at each simulated altitude. These results support previous studies that investigated the effects of hypoxia on alternative measures of the critical intensity of exercise and will inform exercise prescription/monitoring across altitudes.
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Affiliation(s)
- Austin T Beever
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Andrea Y Zhuang
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Juan M Murias
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Saied J Aboodarda
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Martin J MacInnis
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
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Beneke R, Leithäuser RM. Cadence Paradox in Cycling-Part 2: Theory and Simulation of Maximal Lactate Steady State and Carbohydrate Utilization Dependent on Cycling Cadence. Int J Sports Physiol Perform 2024; 19:677-684. [PMID: 38754858 DOI: 10.1123/ijspp.2023-0428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 03/16/2024] [Accepted: 03/21/2024] [Indexed: 05/18/2024]
Abstract
PURPOSE To develop and evaluate a theory on the frequent observation that cyclists prefer cadences (RPMs) higher than those considered most economical at submaximal exercise intensities via modeling and simulation of its mathematical description. METHODS The theory combines the parabolic power-to-velocity (v) relationship, where v is defined by crank length, RPM-dependent ankle velocity, and gear ratio, RPM effects on the maximal lactate steady state (MLSS), and lactate-dependent carbohydrate oxidation (CHO). It was tested against recent experimental results of 12 healthy male recreational cyclists determining the v-dependent peak oxygen uptake (VO2PEAKv), MLSS (MLSSv), corresponding power output (PMLSSv), oxygen uptake at PMLSSv (VO2MLSSv), and CHOMLSSv-management at 100 versus 50 per minute, respectively. Maximum RPM (RPMMAX) attained at minimized pedal torque was measured. RPM-specific maximum sprint power output (PMAXv) was estimated at RPMs of 100 and 50, respectively. RESULTS Modeling identified that MLSSv and PMLSSv related to PMAXv (IPMLSSv) promote CHO and that VO2MLSSv related to VO2PEAKv inhibits CHO. It shows that cycling at higher RPM reduces IPMLSSv. It suggests that high cycling RPMs minimize differences in the reliance on CHO at MLSSv between athletes with high versus low RPMMAX. CONCLUSIONS The present theory-guided modeling approach is exclusively based on data routinely measured in high-performance testing. It implies a higher performance reserve above IPMLSSv at higher RPM. Cyclists may prefer high cycling RPMs because they appear to minimize differences in the reliance on CHO at MLSSv between athletes with high versus low RPMMAX.
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Affiliation(s)
- Ralph Beneke
- Medizin Training und Gesundheit, Philipps Universität Marburg, Marburg, Germany
| | - Renate M Leithäuser
- Medizin Training und Gesundheit, Philipps Universität Marburg, Marburg, Germany
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Beneke R, Granseyer M, Leithäuser RM. Cadence Paradox in Cycling-Part 1: Maximal Lactate Steady State and Carbohydrate Utilization Dependent on Cycling Cadence. Int J Sports Physiol Perform 2024; 19:558-564. [PMID: 38521054 DOI: 10.1123/ijspp.2023-0427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 01/21/2024] [Accepted: 02/19/2024] [Indexed: 03/25/2024]
Abstract
PURPOSE To assess (1) whether and how a higher maximal lactate steady state (MLSS) at higher cycling cadence (RPM) comes along with higher absolute and/or fractional carbohydrate combustion (CHOMLSS), respectively, and (2) whether there is an interrelation between potential RPM-dependent MLSS effects and the maximally achievable RPM (RPMMAX). METHODS Twelve healthy males performed incremental load tests to determine peak power, peak oxygen uptake, and 30-minute MLSS tests at 50 and 100 per minute, respectively, to assess RPM-dependent MLSS, corresponding power output, CHOMLSS responses, and 6-second sprints to measure RPMMAX. RESULTS Peak power, peak carbon dioxide production, and power output at MLSS were lower (P = .000, ω2 = 0.922; P = .044, ω2 > 0.275; and P = .016, ω2 = 0.373) at 100 per minute than at 50 per minute. With 6.0 (1.5) versus 3.8 (1.2) mmol·L-1, MLSS was higher (P = .000, ω2 = 0.771) at 100 per minute than at 50 per minute. No corresponding RPM-dependent differences were found in oxygen uptake at MLSS, carbon dioxide production at MLSS, respiratory exchange ratio at MLSS, CHOMLSS, or fraction of oxygen uptake used for CHO at MLSS, respectively. There was no correlation between the RPM-dependent difference in MLSS and RPMMAX. CONCLUSIONS The present study extends the previous finding of a consistently higher MLSS at higher RPM by indicating (1) that at fully established MLSS conditions, respiration and CHOMLSS management do not differ significantly between 100 per minute and 50 per minute, and (2) that linear correlation models did not identify linear interdependencies between RPM-dependent MLSS conditions and RPMMAX.
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Affiliation(s)
- Ralph Beneke
- Medizin Training und Gesundheit, Philipps Universität Marburg, Marburg, Germany
| | - Marisa Granseyer
- Medizin Training und Gesundheit, Philipps Universität Marburg, Marburg, Germany
| | - Renate M Leithäuser
- Medizin Training und Gesundheit, Philipps Universität Marburg, Marburg, Germany
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Dimmick HL, van Rassel CR, MacInnis MJ, Ferber R. Use of subject-specific models to detect fatigue-related changes in running biomechanics: a random forest approach. Front Sports Act Living 2023; 5:1283316. [PMID: 38186400 PMCID: PMC10768007 DOI: 10.3389/fspor.2023.1283316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/08/2023] [Indexed: 01/09/2024] Open
Abstract
Running biomechanics are affected by fatiguing or prolonged runs. However, no evidence to date has conclusively linked this effect to running-related injury (RRI) development or performance implications. Previous investigations using subject-specific models in running have demonstrated higher accuracy than group-based models, however, this has been infrequently applied to fatigue. In this study, two experiments were conducted to determine whether subject-specific models outperformed group-based models to classify running biomechanics during non-fatigued and fatigued conditions. In the first experiment, 16 participants performed four treadmill runs at or around the maximal lactate steady state. In the second experiment, nine participants performed five prolonged runs using commercial wearable devices. For each experiment, two segments were extracted from each trial from early and late in the run. For each participant, a random forest model was applied with a leave-one-run-out cross-validation to classify between the early (non-fatigued) and late (fatigued) segments. Additionally, group-based classifiers with a leave-one-subject-out cross validation were constructed. For experiment 1, mean classification accuracies for the single-subject and group-based classifiers were 68.2 ± 8.2% and 57.0 ± 8.9%, respectively. For experiment 2, mean classification accuracies for the single-subject and group-based classifiers were 68.9 ± 17.1% and 61.5 ± 11.7%, respectively. Variable importance rankings were consistent within participants, but these rankings differed from each participant to those of the group. Although the classification accuracies were relatively low, these findings highlight the advantage of subject-specific classifiers to detect changes in running biomechanics with fatigue and indicate the potential of using big data and wearable technology approaches in future research to determine possible connections between biomechanics and RRI.
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Affiliation(s)
- Hannah L. Dimmick
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Cody R. van Rassel
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Martin J. MacInnis
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Reed Ferber
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Running Injury Clinic, Calgary, AB, Canada
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McDougall RM, Tripp TR, Frankish BP, Doyle-Baker PK, Lun V, Wiley JP, Aboodarda SJ, MacInnis MJ. The influence of skeletal muscle mitochondria and sex on critical torque and performance fatiguability in humans. J Physiol 2023; 601:5295-5316. [PMID: 37902588 DOI: 10.1113/jp284958] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 10/04/2023] [Indexed: 10/31/2023] Open
Abstract
Critical torque (CT) represents the highest oxidative steady state for intermittent knee extensor exercise, but the extent to which it is influenced by skeletal muscle mitochondria and sex is unclear. Vastus lateralis muscle biopsy samples were collected from 12 females and 12 males -matched for relative maximal oxygen uptake normalized to fat-free mass (FFM) (F: 57.3 (7.5) ml (kg FFM)-1 min-1 ; M: 56.8 (7.6) ml (kg FFM)-1 min-1 ; P = 0.856) - prior to CT determination and performance fatiguability trials. Males had a lower proportion of myosin heavy chain (MHC) I isoform (40.6 (18.4)%) compared to females (59.5 (18.9)%; P = 0.021), but MHC IIa and IIx isoform distributions and protein markers of mitochondrial content were not different between sexes (P > 0.05). When normalized to maximum voluntary contraction (MVC), the relative CT (F: 42.9 (8.3)%; M: 37.9 (9.0)%; P = 0.172) and curvature constant, W' (F: 26.6 (11.0) N m s (N m)-1 ; M: 26.4 (6.5) N m s (N m)-1 ; P = 0.962) were not significantly different between sexes. All protein biomarkers of skeletal muscle mitochondrial content, as well as the proportion of MHC I isoform, positively correlated with relative CT (0.48 < r < 0.70; P < 0.05), and the proportion of MHC IIx isoform correlated positively with relative W' (r = 0.57; P = 0.007). Indices of performance fatiguability were not different between males and females for MVC- and CT-controlled trials (P > 0.05). Greater mitochondrial protein abundance was associated with attenuated declines in potentiated twitch torque for exercise at 60% MVC (P < 0.05); however, the influence of mitochondrial protein abundance on performance fatiguability was reduced when exercise was prescribed relative to CT. Whether these findings translate to whole-body exercise requires additional research. KEY POINTS: The quadriceps critical torque represents the highest intensity of intermittent knee extensor exercise for which an oxidative steady state is attainable, but its relationship with skeletal muscle mitochondrial protein abundance is unknown. Matching males and females for maximal oxygen uptake relative to fat-free mass facilitates investigations of sex differences in exercise physiology, but studies that have compared critical torque and performance fatiguability during intermittent knee extensor exercise have not ensured equal aerobic fitness between sexes. Skeletal muscle mitochondrial protein abundance was correlated with critical torque and fatigue resistance for exercise prescribed relative to maximum voluntary contraction but not for exercise performed relative to the critical torque. Differences between sexes in critical torque, skeletal muscle mitochondrial protein abundance and performance fatiguability were not statistically significant. Our results suggest that skeletal muscle mitochondrial protein abundance may contribute to fatigue resistance by influencing the critical intensity of exercise.
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Affiliation(s)
| | - Thomas R Tripp
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | | | | | - Victor Lun
- Faculty of Kinesiology, University of Calgary Sport Medicine Centre, University of Calgary, Calgary, Alberta, Canada
| | - J Preston Wiley
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Faculty of Kinesiology, University of Calgary Sport Medicine Centre, University of Calgary, Calgary, Alberta, Canada
| | - S Jalal Aboodarda
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Martin J MacInnis
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
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van den Brandt FAP, Khudair M, Hettinga FJ, Elferink-Gemser MT. Be Aware of the Benefits of Drafting in Sports and Take Your Advantage: A Meta-Analysis. TRANSLATIONAL SPORTS MEDICINE 2023; 2023:3254847. [PMID: 38654910 PMCID: PMC11022785 DOI: 10.1155/2023/3254847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/07/2023] [Accepted: 10/13/2023] [Indexed: 04/26/2024]
Abstract
Purpose In competitive sports, optimizing performance is the key. An interesting venue to explore is to consider drafting as a pacing strategy. The purpose of this study is to identify the magnitude of drafting benefits for biomechanical, physiological, and psychobiological parameters in and between athletes in cycling, kayaking, running, skating, skiing, and swimming. Design A systematic review and meta-analysis. Methods Systematic searches were performed in PubMed, Web of Science, and Embase databases. Results In total, 205 studies were found, from which 22 were relevant (including 232 participants and 548 observations). Methodological quality was high for all the included articles. The meta-analyses for all parameters indicated strong evidence for a benefit of drafting, with moderate effects between leading and drafting athletes found for the heart rate (3.9%), VO2 (8.9%), power output (11.3%), and rating of perceived exertion (10.4%). Large effect sizes were found for blood lactate (24.2%), VE (16.2%), and EMG (56.4%). A moderator analysis showed differences between sports on the effect of drafting with most benefits in cycling. Discussion. Based on the observed effects of drafting in the biomechanical, physiological, and psychobiological parameters, it can be considered as an element of pacing, a strategy to conserve energy and optimize performance. Conclusion There is strong evidence that drafting benefits athletes, with varying levels of effect for athletes in different sports. Knowledge about the magnitude of benefits can be used to improve training sessions, race strategies, and performance in competition.
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Affiliation(s)
- Floor A. P. van den Brandt
- Department of Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Mohammed Khudair
- Department of Sport, Exercise & Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, UK
| | - Florentina J. Hettinga
- Department of Sport, Exercise & Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, UK
| | - Marije T. Elferink-Gemser
- Department of Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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van Rassel CR, Ajayi OO, Sales KM, Griffiths JK, Fletcher JR, Edwards WB, MacInnis MJ. Is Running Power a Useful Metric? Quantifying Training Intensity and Aerobic Fitness Using Stryd Running Power Near the Maximal Lactate Steady State. SENSORS (BASEL, SWITZERLAND) 2023; 23:8729. [PMID: 37960430 PMCID: PMC10649254 DOI: 10.3390/s23218729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023]
Abstract
We sought to determine the utility of Stryd, a commercially available inertial measurement unit, to quantify running intensity and aerobic fitness. Fifteen (eight male, seven female) runners (age = 30.2 [4.3] years; V·O2max = 54.5 [6.5] ml·kg-1·min-1) performed moderate- and heavy-intensity step transitions, an incremental exercise test, and constant-speed running trials to establish the maximal lactate steady state (MLSS). Stryd running power stability, sensitivity, and reliability were evaluated near the MLSS. Stryd running power was also compared to running speed, V·O2, and metabolic power measures to estimate running mechanical efficiency (EFF) and to determine the efficacy of using Stryd to delineate exercise intensities, quantify aerobic fitness, and estimate running economy (RE). Stryd running power was strongly associated with V·O2 (R2 = 0.84; p < 0.001) and running speed at the MLSS (R2 = 0.91; p < 0.001). Stryd running power measures were strongly correlated with RE at the MLSS when combined with metabolic data (R2 = 0.79; p < 0.001) but not in isolation from the metabolic data (R2 = 0.08; p = 0.313). Measures of running EFF near the MLSS were not different across intensities (~21%; p > 0.05). In conclusion, although Stryd could not quantify RE in isolation, it provided a stable, sensitive, and reliable metric that can estimate aerobic fitness, delineate exercise intensities, and approximate the metabolic requirements of running near the MLSS.
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Affiliation(s)
- Cody R. van Rassel
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.R.v.R.)
| | | | - Kate M. Sales
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.R.v.R.)
| | - James K. Griffiths
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.R.v.R.)
| | - Jared R. Fletcher
- Department of Health and Physical Education, Mount Royal University, Calgary, AB T3E 6K6, Canada
| | - W. Brent Edwards
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.R.v.R.)
| | - Martin J. MacInnis
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.R.v.R.)
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Gures A, Colakoglu M, Ozkaya O, As H, Balci GA. Cardiovascular responses of exercises performed within the extreme exercise domain. Physiol Res 2023; 72:319-327. [PMID: 37449745 PMCID: PMC10668999 DOI: 10.33549/physiolres.935068] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 03/03/2023] [Indexed: 08/26/2023] Open
Abstract
Stroke volume (SV), heart rate (HR) and arterio-venous O2 difference (a-vO2diff) responses to heavy and severe-intensity exercise have been well documented; however, there is a lack of information on the SV, HR and a v-O2diff responses of work rates within extreme exercise domain. The aim of this study was, therefore, to focus on central and peripheral components of VO2 responses to exercises performed within the heavy, severe and extreme exercise domain. Eight well-trained male cyclists participated in this study. Maximal O2 consumption (VO2max) and corresponding work rate (P@VO2max) were determined by multisession constant work rate exercises. Cardiovascular responses to exercises were evaluated by nitrous-oxide rebreathing method with work rates from 40 % to 160 % of P@VO2max, VO2max corresponded to 324+/-39.4 W; however, maximal SV responses occurred at 205+/-54.3 W (p<0.01). Maximal cardiac output (Q), HR, and a vO2diff responses were revealed by the P@VO2max. VO2 response to exercise significantly decreased from severe-intense exercises to the first work rate of extreme exercise domain due to significant decreases in Q, SV, and HR responses (p<0.05), except a v-O2diff (p>0.05). Moreover, non-significant decreases in Q, SV, and a v-O2diff were evaluated as response to increase in work rate belonging to extreme work rates (p>0.05), except the HR (p<0.05). Work rates within the lower district of the extreme exercise domain have an important potential to improve peripheral component of VO2, while the P@VO2max seems the most appropriate intensity for aerobic endurance development as it maximizes the central component of VO2max.
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Affiliation(s)
- A Gures
- Department of Coaching Education, Faculty of Sports Sciences, Adnan Menderes University, Aydin, Republic of Türkiye, Department of Coaching Education, Faculty of Sports Sciences, Ege University, Izmir, Republic of Türkiye.
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9
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Hill DW. A Physiological Anchor for the Perception of Effort. Percept Mot Skills 2023:315125231180383. [PMID: 37308451 DOI: 10.1177/00315125231180383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This is a two-part study to determine one or more reliable physiological anchors for perception of effort. The purpose of Study 1 was to compare ratings of perceived exertion (RPE) at the ventilatory threshold (VT) in running, cycling, and upper body exercise with the premise that if RPE at VT did not differ across exercise modes, VT might provide a unique set of physiological inputs for perception of effort. For 27 participants, values for VT and for RPE at VT (Borg 6 to 20 scale) averaged 9.4 km⋅h-1 (SD = 0.7) and 11.9 km⋅h-1 (SD = 1.4) respectively in running, 135 W (SD = 24) and 12.1 W (SD = 1.6) in cycling, and 46 W (SD = 5) and 12.0 W (SD = 1.7) in upper body exercise. RPE did not differ, suggesting that VT may anchor effort perception. In Study 2, 10 participants performed cycle ergometer exercise for 30 minutes at their VT (M = 101 W, SD = 21), at their maximal lactate steady state (M = 143 W, SD = 22), and at their critical power (CP; M = 167 W, SD = 23). Mean end-exercise RPE were 12.1 (SD = 2.1), 15.0 (SD = 1.9), and 19.0 (SD = 0.5), respectively. The very close clustering of RPE during exercise at CP hints that the confluence of physiological responses at CP may (also) serve as a determinant in perception of effort.
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Affiliation(s)
- David W Hill
- Applied Physiology Laboratory, Department of Kinesiology, Health Promotion, and Recreation, University of North Texas, Denton, TX, USA
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Burnley M. Invited review: The speed-duration relationship across the animal kingdom. Comp Biochem Physiol A Mol Integr Physiol 2023; 279:111387. [PMID: 36740171 DOI: 10.1016/j.cbpa.2023.111387] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/25/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
The parameters of the hyperbolic speed-duration relationship (the asymptote critical speed, CS, and the curvature constant, D') provide estimates of the maximal steady state speed (CS) and the distance an animal can run, swim, or fly at speeds above CS before it is forced to slow down or stop (D'). The speed-duration relationship has been directly studied in humans, horses, mice and rats. The technical difficulties with treadmill running in dogs and the relatively short greyhound race durations means that, perhaps surprisingly, it has not been assessed in dogs. The endurance capabilities of lizards, crabs and salamanders has also been measured, and the speed-duration relationship can be calculated from these data. These analyses show that 1) raising environmental temperature from 25 °C to 40 °C in lizards can double the CS with no change in D'; 2) that lungless salamanders have an extremely low critical speed due, most likely, to O2 diffusion limitations associated with cutaneous respiration; and 3) the painted ghost crab possesses the highest endurance parameter ratio (D'/CS) yet recorded (470 s), allowing it to maintain high speeds for extended periods. Although the speed-duration relationship has not been measured in fish, the sustainable swimming speed has been quantified in a range of species and is conceptually similar to the maximal steady state in humans. The high aerobic power of birds and low metabolic cost of transport during flight permits the extreme feats of endurance observed in bird migrations. However, the parameters of the avian speed-duration relationship have not been quantified.
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Affiliation(s)
- Mark Burnley
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, UK.
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Römer C, Wolfarth B. Prediction of Relevant Training Control Parameters at Individual Anaerobic Threshold without Blood Lactate Measurement. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:4641. [PMID: 36901647 PMCID: PMC10001845 DOI: 10.3390/ijerph20054641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Active exercise therapy plays an essential role in tackling the global burden of obesity. Optimizing recommendations in individual training therapy requires that the essential parameters heart rate HR(IAT) and work load (W/kg(IAT) at individual anaerobic threshold (IAT) are known. Performance diagnostics with blood lactate is one of the most established methods for these kinds of diagnostics, yet it is also time consuming and expensive. METHODS To establish a regression model which allows HR(IAT) and (W/kg(IAT) to be predicted without measuring blood lactate, a total of 1234 performance protocols with blood lactate in cycle ergometry were analyzed. Multiple linear regression analyses were performed to predict the essential parameters (HR(IAT)) (W/kg(IAT)) by using routine parameters for ergometry without blood lactate. RESULTS HR(IAT) can be predicted with an RMSE of 8.77 bpm (p < 0.001), R2 = 0.799 (|R| = 0.798) without performing blood lactate diagnostics during cycle ergometry. In addition, it is possible to predict W/kg(IAT) with an RMSE (root mean square error) of 0.241 W/kg (p < 0.001), R2 = 0.897 (|R| = 0.897). CONCLUSIONS It is possible to predict essential parameters for training management without measuring blood lactate. This model can easily be used in preventive medicine and results in an inexpensive yet better training management of the general population, which is essential for public health.
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VAN Rassel CR, Ajayi OO, Sales KM, Azevedo RA, Murias JM, Macinnis MJ. A "Step-Ramp-Step" Protocol to Identify Running Speed and Power Associated with the Maximal Metabolic Steady State. Med Sci Sports Exerc 2023; 55:534-547. [PMID: 36251387 DOI: 10.1249/mss.0000000000003066] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
PURPOSE A previously established Step-Ramp-Step (SRS) exercise protocol was able to accurately predict the work rate associated with the maximal metabolic steady state (MMSS) in cyclists. The purpose of this study was to determine whether a modified SRS protocol could predict the running speed and power associated with the MMSS. METHODS Fifteen (8 male; 7 female) runners (V̇O 2max 54.5 [6.5] mL·kg -1 ·min -1 ) were recruited for this investigation composed of four to five visits. In the first visit, runners performed a moderate intensity step (MOD), an incremental exercise test, and a heavy intensity step (HVY), on a motorized treadmill. This SRS protocol was used to predict the running speed and power associated with the MMSS (i.e., the SRS-MMSS), where running power was assessed by a wearable device (Stryd) attached to each runner's shoe. Subsequent visits were used to confirm the maximal lactate steady state (MLSS) as a proxy measure of the MMSS (i.e., the MLSS-MMSS) and to validate the SRS-MMSS speed and power estimates. RESULTS The estimated SRS-MMSS running speed (7.2 [0.6] mph) was significantly lower than confirmed running speed at MLSS-MMSS (7.5 [0.8] mph; bias = 3.6%, P = 0.005); however, the estimated SRS-MMSS running power (241 [35] W) was not different than the MLSS-MMSS confirmed running power (240 [37] W; bias = -0.6%; P = 0.435). V̇O 2 at SRS-MMSS (3.22 [0.49] L·min -1 ) was not different than respiratory compensation point (3.26 [0.58] L·min -1 ; P = 0.430). Similarly, V̇O 2 at MLSS-MMSS (3.30 [0.54] L·min -1 ) was not different than respiratory compensation point ( P = 0.438). CONCLUSIONS The SRS protocol allows MMSS, as measured by MLSS, to be accurately determined using running power (Stryd), but not speed, in a single laboratory visit.
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Affiliation(s)
- Cody R VAN Rassel
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, CANADA
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13
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Dimmick HL, van Rassel CR, MacInnis MJ, Ferber R. Between-Day Reliability of Commonly Used IMU Features during a Fatiguing Run and the Effect of Speed. SENSORS 2022; 22:s22114129. [PMID: 35684750 PMCID: PMC9185649 DOI: 10.3390/s22114129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/20/2022] [Accepted: 05/26/2022] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to determine if fatigue-related changes in biomechanics derived from an inertial measurement unit (IMU) placed at the center of mass (CoM) are reliable day-to-day. Sixteen runners performed two runs at maximal lactate steady state (MLSS) on a treadmill, one run 5% above MLSS speed, and one run 5% below MLSS speed while wearing a CoM-mounted IMU. Trials were performed to volitional exhaustion or a specified termination time. IMU features were derived from each axis and the resultant. Feature means were calculated for each subject during non-fatigued and fatigued states. Comparisons were performed between the two trials at MLSS and between all four trials. The only significant fatigue state × trial interaction was the 25th percentile of the results when comparing all trials. There were no main effects for trial for either comparison method. There were main effects for fatigue state for most features in both comparison methods. Reliability, measured by an intraclass coefficient (ICC), was good-to-excellent for most features. These results suggest that fatigue-related changes in biomechanics derived from a CoM-mounted IMU are reliable day-to-day when participants ran at or around MLSS and are not significantly affected by slight deviations in speed.
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Affiliation(s)
- Hannah L. Dimmick
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.R.v.R.); (M.J.M.); (R.F.)
- Correspondence: ; Tel.: +1-403-220-2874
| | - Cody R. van Rassel
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.R.v.R.); (M.J.M.); (R.F.)
| | - Martin J. MacInnis
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.R.v.R.); (M.J.M.); (R.F.)
| | - Reed Ferber
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada; (C.R.v.R.); (M.J.M.); (R.F.)
- Faculty of Nursing, University of Calgary, Calgary, AB T2N 1N4, Canada
- Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
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Abstract
The elegant concept of a hyperbolic relationship between power, velocity, or torque and time to exhaustion has rightfully captivated the imagination and inspired extensive research for over half a century. Theoretically, the relationship's asymptote along the time axis (critical power, velocity, or torque) indicates the exercise intensity that could be maintained for extended durations, or the "heavy-severe exercise boundary". Much more than a critical mass of the extensive accumulated evidence, however, has persistently shown the determined intensity of critical power and its variants as being too high to maintain for extended periods. The extensive scientific research devoted to the topic has almost exclusively centered around its relationships with various endurance parameters and performances, as well as the identification of procedural problems and how to mitigate them. The prevalent underlying premise has been that the observed discrepancies are mainly due to experimental 'noise' and procedural inconsistencies. Consequently, little or no effort has been directed at other perspectives such as trying to elucidate physiological reasons that possibly underly and account for those discrepancies. This review, therefore, will attempt to offer a new such perspective and point out the discrepancies' likely root causes.
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Affiliation(s)
- Raffy Dotan
- Kinesiology Department, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada.
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15
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Nixon RJ, Kranen SH, Vanhatalo A, Jones AM. Steady-state [Formula: see text] above MLSS: evidence that critical speed better represents maximal metabolic steady state in well-trained runners. Eur J Appl Physiol 2021; 121:3133-3144. [PMID: 34351531 PMCID: PMC8505327 DOI: 10.1007/s00421-021-04780-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 07/26/2021] [Indexed: 11/26/2022]
Abstract
The metabolic boundary separating the heavy-intensity and severe-intensity exercise domains is of scientific and practical interest but there is controversy concerning whether the maximal lactate steady state (MLSS) or critical power (synonymous with critical speed, CS) better represents this boundary. We measured the running speeds at MLSS and CS and investigated their ability to discriminate speeds at which \documentclass[12pt]{minimal}
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\begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2 was stable over time from speeds at which a steady-state \documentclass[12pt]{minimal}
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\begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2 could not be established. Ten well-trained male distance runners completed 9–12 constant-speed treadmill tests, including 3–5 runs of up to 30-min duration for the assessment of MLSS and at least 4 runs performed to the limit of tolerance for assessment of CS. The running speeds at CS and MLSS were significantly different (16.4 ± 1.3 vs. 15.2 ± 0.9 km/h, respectively; P < 0.001). Blood lactate concentration was higher and increased with time at a speed 0.5 km/h higher than MLSS compared to MLSS (P < 0.01); however, pulmonary \documentclass[12pt]{minimal}
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\begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2 did not change significantly between 10 and 30 min at either MLSS or MLSS + 0.5 km/h. In contrast, \documentclass[12pt]{minimal}
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\begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2 increased significantly over time and reached \documentclass[12pt]{minimal}
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\begin{document}$$\dot{V}{\text{O}}_{2\,\,\max }$$\end{document}V˙O2max at end-exercise at a speed ~ 0.4 km/h above CS (P < 0.05) but remained stable at a speed ~ 0.5 km/h below CS. The stability of \documentclass[12pt]{minimal}
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\begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2 at a speed exceeding MLSS suggests that MLSS underestimates the maximal metabolic steady state. These results indicate that CS more closely represents the maximal metabolic steady state when the latter is appropriately defined according to the ability to stabilise pulmonary \documentclass[12pt]{minimal}
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\begin{document}$$\dot{V}{\text{O}}_{2}$$\end{document}V˙O2.
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Affiliation(s)
- Rebekah J Nixon
- Sport and Health Sciences, University of Exeter, St. Luke's Campus, Heavitree Road, Exeter, EX12LU, UK
| | - Sascha H Kranen
- Sport and Health Sciences, University of Exeter, St. Luke's Campus, Heavitree Road, Exeter, EX12LU, UK
| | - Anni Vanhatalo
- Sport and Health Sciences, University of Exeter, St. Luke's Campus, Heavitree Road, Exeter, EX12LU, UK
| | - Andrew M Jones
- Sport and Health Sciences, University of Exeter, St. Luke's Campus, Heavitree Road, Exeter, EX12LU, UK.
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16
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The Importance of 'Durability' in the Physiological Profiling of Endurance Athletes. Sports Med 2021; 51:1619-1628. [PMID: 33886100 DOI: 10.1007/s40279-021-01459-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2021] [Indexed: 12/17/2022]
Abstract
Profiling physiological attributes is an important role for applied exercise physiologists working with endurance athletes. These attributes are typically assessed in well-rested athletes. However, as has been demonstrated in the literature and supported by field data presented here, the attributes measured during routine physiological-profiling assessments are not static, but change over time during prolonged exercise. If not accounted for, shifts in these physiological attributes during prolonged exercise have implications for the accuracy of their use in intensity regulation during prolonged training sessions or competitions, quantifying training adaptations, training-load programming and monitoring, and the prediction of exercise performance. In this review, we argue that current models used in the routine physiological profiling of endurance athletes do not account for these shifts. Therefore, applied exercise physiologists working with endurance athletes would benefit from development of physiological-profiling models that account for shifts in physiological-profiling variables during prolonged exercise and quantify the 'durability' of individual athletes, here defined as the time of onset and magnitude of deterioration in physiological-profiling characteristics over time during prolonged exercise. We propose directions for future research and applied practice that may enable better understanding of athlete durability.
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Possamai LT, Borszcz FK, de Aguiar RA, de Lucas RD, Turnes T. Agreement of maximal lactate steady state with critical power and physiological thresholds in rowing. Eur J Sport Sci 2021; 22:371-380. [PMID: 33428539 DOI: 10.1080/17461391.2021.1874541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The aim of this study was threefold: (a) to compare the maximal lactate steady state (MLSS) with critical power (CP); (b) to describe the relationship of MLSS with rowing performances; and (c) to verify the agreement of MLSS with several exercise intensity thresholds in rowers. Fourteen male rowers (mean [SD]: age = 26 [13] years; height = 1.82 [0.05] m; body mass = 81.0 [7.6] kg) performed on a rowing ergometer: (I) discontinuous incremental test with 3 min stages and 30-s recovery intervals (INC3min); (II) continuous incremental test with 60-s stages (INC1min); (III) two to four constant workload tests to determine MLSS; and (IV) performance tests of 500, 1000, 2000 and 6000 m to determine CP. Twenty-seven exercise intensity thresholds based on blood lactate, heart rate and ventilatory responses were determined by incremental tests, and then compared with MLSS. CP (257 [38] W) was higher than MLSS (187 [25] W; p < 0.001), with a very large mean difference (37%), large typical error of estimate (14%) and moderate correlation (r = 0.48). Despite the correlations between MLSS and most intensity thresholds (r > 0.70), all presented low correspondence (TEE > 5%), with a lower bias found between MLSS and the first intensity thresholds (-12.5% to 4.1%). MLSS was correlated with mean power during 500 m (r = 0.65), 1000 m (r = 0.86) and 2000 m (r = 0.78). In conclusion, MLSS intensity is substantially lower than CP and presented low agreement with 27 incremental-derived thresholds, questioning their use to estimate MLSS during rowing ergometer exercise.Highlights MLSS was substantially lower than CP in rowing exercise with a mean difference of 37%, much larger than the difference commonly found in running and cycling exercise (i.e., ?10%).A clear disagreement was reported between MLSS and 27 physiological thresholds determined in different incremental tests.There is a positive association of MLSS with 500, 1000 and 2000 m rowing ergometer performance tests.
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Affiliation(s)
| | - Fernando Klitzke Borszcz
- Sports Center, Physical Effort Laboratory, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Rafael Alves de Aguiar
- Human Performance Research Group, Center for Health and Sport Science, Santa Catarina State University, Florianópolis, Brazil
| | - Ricardo Dantas de Lucas
- Sports Center, Physical Effort Laboratory, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Tiago Turnes
- Sports Center, Physical Effort Laboratory, Federal University of Santa Catarina, Florianópolis, Brazil
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18
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Perret C, Hartmann K. Heart Rate-based Lactate Minimum Test in Running and Cycling. Int J Sports Med 2021; 42:812-817. [PMID: 33506446 DOI: 10.1055/a-1342-7744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The heart rate-based lactate minimum test is a highly reproducible exercise test. However, the relation between lactate minimum determined by this test and maximal lactate steady state in running and cycling is still unclear. Twelve endurance-trained men performed this test in running and cycling. Exercise intensity at maximal lactate steady state was determined by performing several constant heart rate endurance tests for both exercise modes. Heart rate, power output, lactate concentration, oxygen uptake and rating of perceived exertion at lactate minimum, maximal lactate steady state and maximal performance were analysed. All parameters were significantly higher at maximal lactate steady state compared to lactate minimum for running and cycling. Significant correlations (p<0.05) between maximal lactate steady state and lactate minimum data were found. Peak heart rate and peak oxygen uptake were significantly higher for running versus cycling. Nevertheless, the exercise mode had no influence on relative (in percentage of maximal values) heart rate at lactate minimum (p=0.099) in contrast to relative power output (p=0.002). In conclusion, all measured parameters at lactate minimum were significantly lower but highly correlated with values at maximal lactate steady state in running and cycling, which allows to roughly estimate exercise intensity at maximal lactate steady state with one single exercise test.
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Affiliation(s)
- Claudio Perret
- Institute of Sports Medicine, Swiss Paraplegic Centre, Nottwil, Switzerland
| | - Kathrin Hartmann
- Institute of Human Movement Sciences and Sport, ETH Zürich, Zurich, Switzerland
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19
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Can an Incremental Step Test Be Used for Maximal Lactate Steady State Determination in Swimming? Clues for Practice. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18020477. [PMID: 33430166 PMCID: PMC7826783 DOI: 10.3390/ijerph18020477] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/01/2021] [Accepted: 01/03/2021] [Indexed: 12/02/2022]
Abstract
We aimed to compare the velocity, physiological responses, and stroke mechanics between the lactate parameters determined in an incremental step test (IST) and maximal lactate steady state (MLSS). Fourteen well-trained male swimmers (16.8 ± 2.8 years) were timed for 400 m and 200 m (T200). Afterwards, a 7 × 200-m front-crawl IST was performed. Swimming velocity, heart rate (HR), blood lactate concentration (BLC), stroke mechanics, and rate of perceived exertion (RPE) were measured throughout the IST and in the 30-min continuous test (CT) bouts for MLSS determination. Swimming velocities at lactate threshold determined with log-log methodology (1.34 ± 0.06 m∙s−1) and Dmax methodology (1.40 ± 0.06 m∙s−1); and also, the velocity at BLC of 4 mmol∙L−1 (1.36 ± 0.07) were not significantly different from MLSSv, however, Bland–Altman analysis showed wide limits of agreement and the concordance correlation coefficient showed poor strength of agreement between the aforementioned parameters which precludes their interchangeable use. Stroke mechanics, HR, RPE, and BLC in MLSSv were not significantly different from the fourth repetition of IST (85% of T200), which by itself can provide useful support to daily practice of well-trained swimmers. Nevertheless, the determination of MLSSv, based on a CT, remains more accurate for exercise evaluation and prescription.
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20
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The Application of Critical Power, the Work Capacity above Critical Power (W'), and its Reconstitution: A Narrative Review of Current Evidence and Implications for Cycling Training Prescription. Sports (Basel) 2020; 8:sports8090123. [PMID: 32899777 PMCID: PMC7552657 DOI: 10.3390/sports8090123] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/28/2020] [Accepted: 09/02/2020] [Indexed: 12/17/2022] Open
Abstract
The two-parameter critical power (CP) model is a robust mathematical interpretation of the power–duration relationship, with CP being the rate associated with the maximal aerobic steady state, and W′ the fixed amount of tolerable work above CP available without any recovery. The aim of this narrative review is to describe the CP concept and the methodologies used to assess it, and to summarize the research applying it to intermittent cycle training techniques. CP and W′ are traditionally assessed using a number of constant work rate cycling tests spread over several days. Alternatively, both the 3-min all-out and ramp all-out protocols provide valid measurements of CP and W′ from a single test, thereby enhancing their suitability to athletes and likely reducing errors associated with the assumptions of the CP model. As CP represents the physiological landmark that is the boundary between heavy and severe intensity domains, it presents several advantages over the de facto arbitrarily defined functional threshold power as the basis for cycle training prescription at intensities up to CP. For intensities above CP, precise prescription is not possible based solely on aerobic measures; however, the addition of the W′ parameter does facilitate the prescription of individualized training intensities and durations within the severe intensity domain. Modelling of W′ reconstitution extends this application, although more research is needed to identify the individual parameters that govern W′ reconstitution rates and their kinetics.
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21
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Carminatti LJ, Batista BN, da Silva JF, Tramontin AF, Costa VP, de Lucas RD, Borszcz FK. Predicting Maximal Lactate Steady State from Carminatti's Shuttle Run Test in Soccer Players. Int J Sports Med 2020; 42:153-160. [PMID: 32842155 DOI: 10.1055/a-1224-3985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The objective of the present study was to determine the validity of Carminatti's shuttle run incremental test-T-Car derived parameters in estimating the maximal lactate steady state determined in shuttle run format. Eighteen soccer players performed a T-Car test, and several trials to determine the maximal lactate steady state. From T-Car were derived the heart rate deflection point, peak speed, maximal heart rate and parameters resulting from percentage of peak measures. The validity was accessed by Bland-Altman plots, linear regressions, and two one-sided tests of equivalence analysis. The results showed the speed at 80.4% of T-Car peak speed, the heart rate deflection point and the 91.4% of maximal heart rate were equivalent to maximal lactate steady state (Mean difference; ±90% compatibility interval; -0.8; ±1.5%, -0.4; ±1.1%, and 0.0; ±2.7%, respectively). Additionally, peak speed during the T-Car test was a stronger predictor of maximal lactate steady state (MLSS [km/h]=2.57+0.65 × sPeak; r=0.82 [90% CI; 0.62-0.92], standard error of the estimate=3.6%; 90% CI ×/÷1.4). Therefore, soccer players can use the T-Car derived parameters as a noninvasive and practical alternative to estimate the specific maximal lactate steady state for soccer.
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Affiliation(s)
- Lorival José Carminatti
- Center for Health and Sport Sciences, University of Santa Catarina State, Florianópolis, Brazil
| | - Bruna Nunes Batista
- Center for Health and Sport Sciences, University of Santa Catarina State, Florianópolis, Brazil
| | - Juliano Fernandes da Silva
- Research Group for Development of Football and Futsal, Sports Center, Federal University of Santa Catarina, Florianópolis, Brazil
| | | | - Vitor Pereira Costa
- Center for Health and Sport Sciences, University of Santa Catarina State, Florianópolis, Brazil
| | - Ricardo Dantas de Lucas
- Physical Effort Laboratory, Sports Centre, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Fernando Klitzke Borszcz
- Physical Effort Laboratory, Sports Centre, Federal University of Santa Catarina, Florianópolis, Brazil
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22
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Hill DW, McFarlin BK, Vingren JL. Exercise above the maximal lactate steady state does not elicit a V̇O 2 slow component that leads to attainment of V̇O 2max. Appl Physiol Nutr Metab 2020; 46:133-140. [PMID: 32780965 DOI: 10.1139/apnm-2020-0261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
There is a pervasive belief that the severe-intensity domain is defined as work rates above the power associated with a maximal lactate steady state (MLSS) and by a oxygen uptake (V̇O2) response that demonstrates a rapid increase (primary phase) followed by a slower increase (slow component), which leads to maximal oxygen uptake (V̇O2max) if exercise is continued long enough. Fifteen university students performed 5 to 7 tests to calculate power at MLSS (154 ± 29 W). The tests included 30 min of exercise at each of 3 work rates: (i) below (-2 ± 1 W) power at MLSS, (ii) above (+4 ± 1 W) the power at MLSS, and (iii) well above (+19 ± 8 W) power at MLSS. The V̇O2 response in each test was described using mathematical modeling. Contrary to expectation, the response at the supra-MLSS work rates had not 2, but 3, distinct phases: the primary phase and the slow component, plus a "delayed" third phase, which emerged after ∼15 min. V̇O2max was not attained at supra-MLSS work rates. These results challenge commonly held beliefs about definitions and descriptions of exercise intensity domains. Novelty: The V̇O2 response at work rates that are too high to sustain a lactate steady state but not high enough to elicit V̇O2max features not 2, but 3, distinct phases. There is no consensus on whether intensity domains should be defined by their boundaries or by the responses they engender.
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Affiliation(s)
- David W Hill
- Department of Kinesiology, Health Promotion, and Recreation, University of North Texas, Denton, TX 76203-5017, USA
| | - Brian K McFarlin
- Department of Kinesiology, Health Promotion, and Recreation, University of North Texas, Denton, TX 76203-5017, USA.,Department of Biological Sciences, University of North Texas, Denton, TX 76203-5017, USA
| | - Jakob L Vingren
- Department of Kinesiology, Health Promotion, and Recreation, University of North Texas, Denton, TX 76203-5017, USA.,Department of Biological Sciences, University of North Texas, Denton, TX 76203-5017, USA
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The effect of 60 km endurance exercise on serum electrolytes and acid–base balance in the Žemaitukai horses. ACTA VET BRNO 2020. [DOI: 10.2754/avb202089020125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Lithuanian Žemaitukai horse breed is one of the oldest in Europe. Currently, there is a lack of information about the effect of endurance competition on blood indices and acid–base balance in the Žemaitukai horses. The aim of this study was to evaluate the effect of endurance exercise on the acid–base balance and electrolyte indicators of the Žemaitukai horses in an official endurance competition. In total, 48 horses of the Žemaitukai breed competed in endurance competitions over the same distance (60 km). Samples were taken before and immediately after the exercise. The following indicators were analysed: the hydrogen potential (pH), partial carbon dioxide pressure (pCO2), partial oxygen pressure (pO2), base excess in blood (BE), base excess in the extracellular fluid [BE (ecf)], cHCO3 (bicarbonate), cSO2 (oxygen saturation), tCO2 (blood total carbon dioxide), haematocrit (HCT), haemoglobin concentration (cHgb), sodium (Na), potassium (K), calcium (Ca), chlorides (Cl), and lactate (Lac). Increase in pH showed adaptation of the horse metabolism to exercise. Blood changes were caused by the development of dehydration and metabolic alkalosis. According to Lac results, all horses were fit and tolerated well physical activity. The exercise did not significantly affect the demand for minerals. Based on the results obtained, it can be stated that horses of the Žemaitukai breed are suitable for endurance competing.
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Training Considerations for Optimising Endurance Development: An Alternate Concurrent Training Perspective. Sports Med 2020; 49:669-682. [PMID: 30847824 DOI: 10.1007/s40279-019-01072-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Whilst the "acute hypothesis" was originally coined to describe the detrimental effects of concurrent training on strength development, similar physiological processes may occur when endurance training adaptations are compromised. There is a growing body of research indicating that typical resistance exercises impair neuromuscular function and endurance performance during periods of resistance training-induced muscle damage. Furthermore, recent evidence suggests that the attenuating effects of resistance training-induced muscle damage on endurance performance are influenced by exercise intensity, exercise mode, exercise sequence, recovery and contraction velocity of resistance training. By understanding the influence that training variables have on the level of resistance training-induced muscle damage and its subsequent attenuating effects on endurance performance, concurrent training programs could be prescribed in such a way that minimises fatigue between modes of training and optimises the quality of endurance training sessions. Therefore, this review will provide considerations for concurrent training prescription for endurance development based on scientific evidence. Furthermore, recommendations will be provided for future research by identifying training variables that may impact on endurance development as a result of concurrent training.
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Lillo-Beviá JR, Courel-Ibáñez J, Cerezuela-Espejo V, Morán-Navarro R, Martínez-Cava A, Pallarés JG. Is the Functional Threshold Power a Valid Metric to Estimate the Maximal Lactate Steady State in Cyclists? J Strength Cond Res 2019; 36:167-173. [PMID: 31714462 DOI: 10.1519/jsc.0000000000003403] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Lillo-Beviá, JR, Courel-Ibáñez, J, Cerezuela-Espejo, V, Morán-Navarro, R, Martínez-Cava, A, and Pallarés, JG. Is the functional threshold power a valid metric to estimate the maximal lactate steady state in cyclists? J Strength Cond Res XX(X): 000-000, 2019-The aims of this study were to determine (a) the repeatability of a 20-minute time-trial (TT20), (b) the location of the TT20 in relation to the main physiological events of the aerobic-anaerobic transition, and (c) the predictive power of a list of correction factors and linear/multiple regression analysis applied to the TT20 result to estimate the individual maximal lactate steady state (MLSS). Under laboratory conditions, 11 trained male cyclists and triathletes (V[Combining Dot Above]O2max 59.7 ± 3.0 ml·kg·min) completed a maximal graded exercise test to record the power output associated with the first and second ventilatory thresholds and V[Combining Dot Above]O2max measured by indirect calorimetry, several 30 minutes constant tests to determine the MLSS, and 2 TT20 tests with a short warm-up. Very high repeatability of TT20 tests was confirmed (standard error of measurement of ±3 W and smallest detectable change of ±9 W). Validity results revealed that MLSS differed substantially from TT20 (bias = 26 ± 7 W). The maximal lactate steady state was then estimated from the traditional 95% factor (bias = 12 ± 7 W) and a novel individual correction factor (ICF% = MLSS/TT20), resulting in 91% (bias = 1 ± 6 W). Complementary linear (MLSS = 0.7488 × TT20 + 43.24; bias = 0 ± 5 W) and multiple regression analysis (bias = 0 ± 4 W) substantially improved the individual MLSS workload estimation. These findings suggest reconsidering the TT20 procedures and calculations to increase the effectiveness of the MLSS prediction.
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Affiliation(s)
- José Ramón Lillo-Beviá
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, Spain
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26
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Stangier C, Abel T, Zeller S, Quittmann OJ, Perret C, Strüder HK. Comparison of Different Blood Lactate Threshold Concepts for Constant Load Performance Prediction in Spinal Cord Injured Handcyclists. Front Physiol 2019; 10:1054. [PMID: 31611803 PMCID: PMC6777042 DOI: 10.3389/fphys.2019.01054] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 08/02/2019] [Indexed: 11/20/2022] Open
Abstract
Background Endurance capacity is one of the main performance determinants in handcycling. There are two exercise test procedures primarily applied to determine endurance capacity, to verify training adaptations and predict race performance. This study aims to evaluate the agreement of these applied concepts in handcycling. Methods In a repeated measures cross-over design, 11 highly trained male spinal cord injured (Th12 to L1) handcyclists (age: 40 ± 9 years, height: 183 ± 8 cm, body mass: 73.2 ± 8.5 kg) performed a graded exercise test (GXT) and a lactate minimum test (LMT) to determine lactate threshold at 4 mmol L–1 (LT4 mmol L−1) and lactate minimum (LM), respectively. The agreement of both lactate thresholds concepts for constant load performance prediction (change of ≤ 1 mmol L–1 during the last 20 min) was evaluated within constant load tests (CLT; 30 min) at a power output (PO) corresponding to LT4 mmol L–1 and LM. Oxygen uptake (V.O2), respiratory exchange ratio (RER), heart rate (HR) and blood lactate (La) were measured during all tests. Results Power output at the corresponding thresholds (LT4 mmol L−1: 149 ± 34 W vs. LM: 137 ± 18 W) revealed no significant difference (p = 0.06). During the CLT at LT4 mmol⋅L−1 and LM, V.O2, and RPE were not significantly different. However, LA, RER, and HR were significantly higher (p ≤ 0.02) during CLT at LT4 mmol L−1. Bland–Altman plots indicate a wide range of dispersion for all parameters between both lactate threshold concepts. Evaluations of LT4 mmol L−1 and LM did not meet the criteria for constant load performance within the CLT for 33 and 17% of the athletes, respectively. Discussion Both exercise tests and the corresponding lactate threshold concept revealed appropriate estimates to predict a steady state performance for the majority of participants. However, as PO determination at LT4 mmol L−1 and LM exceeds the criteria for constant load performance (increase of ≥ 1 mmol L–1) for 33 and 17% respectively the current results indicate the common criteria for constant load performance (change of ± 1 mmol L–1) might not be sufficiently precise for elite athletes in handcycling. Consequently, exercise test results of elite athletes should be analyzed individually and verified by means of several CLT.
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Affiliation(s)
- Carolin Stangier
- Institute of Movement and Neurosciences, German Sport University Cologne, Cologne, Germany
| | - Thomas Abel
- Institute of Movement and Neurosciences, German Sport University Cologne, Cologne, Germany.,European Research Group in Disability Sport, Cologne, Germany
| | - Sebastian Zeller
- Institute of Movement and Neurosciences, German Sport University Cologne, Cologne, Germany
| | - Oliver Jan Quittmann
- Institute of Movement and Neurosciences, German Sport University Cologne, Cologne, Germany
| | - Claudio Perret
- European Research Group in Disability Sport, Cologne, Germany.,Institute of Sports Medicine, Swiss Paraplegic Centre, Nottwil, Switzerland
| | - Heiko K Strüder
- Institute of Movement and Neurosciences, German Sport University Cologne, Cologne, Germany
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Jones AM, Burnley M, Black MI, Poole DC, Vanhatalo A. The maximal metabolic steady state: redefining the 'gold standard'. Physiol Rep 2019; 7:e14098. [PMID: 31124324 PMCID: PMC6533178 DOI: 10.14814/phy2.14098] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/25/2019] [Accepted: 04/27/2019] [Indexed: 02/06/2023] Open
Abstract
The maximal lactate steady state (MLSS) and the critical power (CP) are two widely used indices of the highest oxidative metabolic rate that can be sustained during continuous exercise and are often considered to be synonymous. However, while perhaps having similarities in principle, methodological differences in the assessment of these parameters typically result in MLSS occurring at a somewhat lower power output or running speed and exercise at CP being sustainable for no more than approximately 20-30 min. This has led to the view that CP overestimates the 'actual' maximal metabolic steady state and that MLSS should be considered the 'gold standard' metric for the evaluation of endurance exercise capacity. In this article we will present evidence consistent with the contrary conclusion: i.e., that (1) as presently defined, MLSS naturally underestimates the actual maximal metabolic steady state; and (2) CP alone represents the boundary between discrete exercise intensity domains within which the dynamic cardiorespiratory and muscle metabolic responses to exercise differ profoundly. While both MLSS and CP may have relevance for athletic training and performance, we urge that the distinction between the two concepts/metrics be better appreciated and that comparisons between MLSS and CP, undertaken in the mistaken belief that they are theoretically synonymous, is discontinued. CP represents the genuine boundary separating exercise in which physiological homeostasis can be maintained from exercise in which it cannot, and should be considered the gold standard when the goal is to determine the maximal metabolic steady state.
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Affiliation(s)
- Andrew M. Jones
- Sport and Health SciencesUniversity of ExeterSt. Luke's CampusExeterUnited Kingdom
| | - Mark Burnley
- School of Sport and Exercise SciencesUniversity of KentMedwayUnited Kingdom
| | - Matthew I. Black
- Sport and Health SciencesUniversity of ExeterSt. Luke's CampusExeterUnited Kingdom
| | - David C. Poole
- Department of KinesiologyKansas State UniversityManhattanKansas
| | - Anni Vanhatalo
- Sport and Health SciencesUniversity of ExeterSt. Luke's CampusExeterUnited Kingdom
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Pelarigo JG, Fernandes RJ, Ribeiro J, Denadai BS, Greco CC, Vilas-Boas JP. Comparison of Different Methods for the Swimming Aerobic Capacity Evaluation. J Strength Cond Res 2018; 32:3542-3551. [DOI: 10.1519/jsc.0000000000001873] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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29
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Hafen PS, Vehrs PR. Sex-Related Differences in the Maximal Lactate Steady State. Sports (Basel) 2018; 6:sports6040154. [PMID: 30486396 PMCID: PMC6316329 DOI: 10.3390/sports6040154] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 11/21/2018] [Accepted: 11/21/2018] [Indexed: 11/16/2022] Open
Abstract
The maximal lactate steady state (MLSS) is one of the factors that differentiates performance in aerobic events. The purpose of this study was to investigate the sex differences in oxygen consumption (VO₂), heart rate (HR), and the respiratory exchange ratio (RER) at the MLSS in well-trained distance runners. Twenty-two (12 female, 10 male) well-trained distance runners (23 ± 5.0 years) performed multiple 30-min steady-state runs to determine their MLSS, during which blood lactate and respiratory gas exchange measures were taken. To interpret the MLSS intensity as a training tool, runners completed a time-to-exhaustion (TTE) run at their MLSS. The relative intensity at which the MLSS occurred was identical between males and females according to both oxygen consumption (83 ± 5 %O₂max) and heart rate (89 ± 7 %HRmax). However, female runners displayed a significantly lower RER at MLSS compared to male runners (p < 0.0001; 0.84 ± 0.02 vs. 0.88 ± 0.04, respectively). There was not a significant difference in TTE at MLSS between males (79 ± 17 min) and females (80 ± 25 min). Due to the observed difference in the RER at the MLSS, it is suggested that RER derived estimates of MLSS be sex-specific. While the RER data suggest that the MLSS represents different metabolic intensities for males and females, the relative training load of MLSS appears to be similar in males and female runners.
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Affiliation(s)
- Paul S Hafen
- Department of Exercise Sciences, 106 SFH; Brigham Young University; Provo, UT 84602, USA.
| | - Pat R Vehrs
- Department of Exercise Sciences, 106 SFH; Brigham Young University; Provo, UT 84602, USA.
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30
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Cerezuela-Espejo V, Courel-Ibáñez J, Morán-Navarro R, Martínez-Cava A, Pallarés JG. The Relationship Between Lactate and Ventilatory Thresholds in Runners: Validity and Reliability of Exercise Test Performance Parameters. Front Physiol 2018; 9:1320. [PMID: 30319439 PMCID: PMC6167480 DOI: 10.3389/fphys.2018.01320] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/31/2018] [Indexed: 01/09/2023] Open
Abstract
The aims of this study were (1) to establish the best fit between ventilatory and lactate exercise performance parameters in running and (2) to explore novel alternatives to estimate the maximal aerobic speed (MAS) in well-trained runners. Twenty-two trained male athletes ( V ˙ O2max 60.2 ± 4.3 ml·kg·min-1) completed three maximal graded exercise tests (GXT): (1) a preliminary GXT to determine individuals' MAS; (2) two experimental GXT individually adjusted by MAS to record the speed associated to the main aerobic-anaerobic transition events measured by indirect calorimetry and capillary blood lactate (CBL). Athletes also performed several 30 min constant running tests to determine the maximal lactate steady state (MLSS). Reliability analysis revealed low CV (<3.1%), low bias (<0.5 km·h-1), and high correlation (ICC > 0.91) for all determinations except V-Slope (ICC = 0.84). Validity analysis showed that LT, LT+1.0, and LT+3.0 mMol·L-1 were solid predictors of VT1 (-0.3 km·h-1; bias = 1.2; ICC = 0.90; p = 0.57), MLSS (-0.2 km·h-1; bias = 1.2; ICC = 0.84; p = 0.74), and VT2 (<0.1 km·h-1; bias = 1.3; ICC = 0.82; p = 0.9l9), respectively. MLSS was identified as a different physiological event and a midpoint between VT1 (bias = -2.0 km·h-1) and VT2 (bias = 2.3 km·h-1). MAS was accurately estimated (SEM ± 0.3 km·h-1) from peak velocity (Vpeak) attained during GXT with the equation: MASEST (km·h-1) = Vpeak (km·h-1) * 0.8348 + 2.308. Current individualized GXT protocol based on individuals' MAS was solid to determine both maximal and submaximal physiological parameters. Lactate threshold tests can be a valid and reliable alternative to VT and MLSS to identify the workloads at the transition from aerobic to anaerobic metabolism in well-trained runners. In contrast with traditional assumption, the MLSS constituted a midpoint physiological event between VT1 and VT2 in runners. The Vpeak stands out as a powerful predictor of MAS.
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Affiliation(s)
- Víctor Cerezuela-Espejo
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, Spain
| | - Javier Courel-Ibáñez
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, Spain
| | - Ricardo Morán-Navarro
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, Spain
| | - Alejandro Martínez-Cava
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, Spain
| | - Jesús G Pallarés
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, Spain
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Dragonea P, Zacharakis E, Kounalakis S, Kostopoulos N, Bolatoglou T, Apostolidis N. Determination of the exercise intensity corresponding with maximal lactate steady state in high-level basketball players. Res Sports Med 2018; 27:112-120. [DOI: 10.1080/15438627.2018.1511559] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Panagiota Dragonea
- Department of Games and Sports, Faculty of Physical Education and Sport Science, University of Athens, Athens, Greece
| | - Emmanuil Zacharakis
- Department of Games and Sports, Faculty of Physical Education and Sport Science, University of Athens, Athens, Greece
| | - Stylianos Kounalakis
- Department of Physical and Cultural Education, Evelpidon Hellenic Military Academy, Vari, Greece
| | - Nikolaos Kostopoulos
- Department of Games and Sports, Faculty of Physical Education and Sport Science, University of Athens, Athens, Greece
| | - Theodoros Bolatoglou
- Department of Games and Sports, Faculty of Physical Education and Sport Science, University of Athens, Athens, Greece
| | - Nikolaos Apostolidis
- Department of Games and Sports, Faculty of Physical Education and Sport Science, University of Athens, Athens, Greece
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Effects of Varying the Step Duration on the Determination of Lactate Thresholds in Elite Rowers. Int J Sports Physiol Perform 2018; 13:687-693. [DOI: 10.1123/ijspp.2017-0258] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study aimed to identify the minimum increment duration required to accurately assess 2 distinct lactate thresholds. A total of 21 elite rowers (12 women and 9 men) participated in this study, and each performed 8 or 9 rowing tests comprising 5 progressive incremental tests (3-, 4-, 5-, 7-, or 10-min steps) and at least three 30-min constant-intensity maximal lactate steady-state assessments. Power output (PO) at lactate threshold 1 was higher in the 3- and 4-min incremental tests. No other measures were different for lactate threshold 1. The PO at the second lactate threshold was different between most tests and was higher than the PO at maximal lactate steady state, except for the 10-min incremental test. Lactate threshold 2 oxygen consumption was higher in the 3-, 4-, and 5-min tests, but heart rate (HR) and rating of perceived exertion were not different between tests. Peak PO in the incremental tests was inversely related to the step durations (r2 = .86, P ≤ .02). Peak oxygen consumption was higher in the shorter (≤5 min) than the longer (≥7 min) incremental tests, whereas peak HR was not different between tests. These data suggest that for the methods used in this study, incremental exercise tests with step durations ≤7 min overestimate maximal lactate steady-state exercise intensity, peak physiological values are best determined using incremental tests with step durations ≤4 min, and HR measures are not affected by step duration, and therefore, prescription of training HRs can be made using any of these tests.
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33
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Loturco I, Pereira LA, Kobal R, Nakamura FY. Using Loaded and Unloaded Jumps to Increase Speed and Power Performance in Elite Young and Senior Soccer Players. Strength Cond J 2018. [DOI: 10.1519/ssc.0000000000000249] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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34
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Ferguson BS, Rogatzki MJ, Goodwin ML, Kane DA, Rightmire Z, Gladden LB. Lactate metabolism: historical context, prior misinterpretations, and current understanding. Eur J Appl Physiol 2018; 118:691-728. [PMID: 29322250 DOI: 10.1007/s00421-017-3795-6] [Citation(s) in RCA: 202] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/22/2017] [Indexed: 02/07/2023]
Abstract
Lactate (La-) has long been at the center of controversy in research, clinical, and athletic settings. Since its discovery in 1780, La- has often been erroneously viewed as simply a hypoxic waste product with multiple deleterious effects. Not until the 1980s, with the introduction of the cell-to-cell lactate shuttle did a paradigm shift in our understanding of the role of La- in metabolism begin. The evidence for La- as a major player in the coordination of whole-body metabolism has since grown rapidly. La- is a readily combusted fuel that is shuttled throughout the body, and it is a potent signal for angiogenesis irrespective of oxygen tension. Despite this, many fundamental discoveries about La- are still working their way into mainstream research, clinical care, and practice. The purpose of this review is to synthesize current understanding of La- metabolism via an appraisal of its robust experimental history, particularly in exercise physiology. That La- production increases during dysoxia is beyond debate, but this condition is the exception rather than the rule. Fluctuations in blood [La-] in health and disease are not typically due to low oxygen tension, a principle first demonstrated with exercise and now understood to varying degrees across disciplines. From its role in coordinating whole-body metabolism as a fuel to its role as a signaling molecule in tumors, the study of La- metabolism continues to expand and holds potential for multiple clinical applications. This review highlights La-'s central role in metabolism and amplifies our understanding of past research.
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Affiliation(s)
- Brian S Ferguson
- College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Matthew J Rogatzki
- Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA
| | - Matthew L Goodwin
- Department of Orthopaedics, University of Utah, Salt Lake City, UT, USA.,Huntsman Cancer Institute, Salt Lake City, UT, USA
| | - Daniel A Kane
- Department of Human Kinetics, St. Francis Xavier University, Antigonish, Canada
| | - Zachary Rightmire
- School of Kinesiology, Auburn University, 301 Wire Road, Auburn, AL, 36849, USA
| | - L Bruce Gladden
- School of Kinesiology, Auburn University, 301 Wire Road, Auburn, AL, 36849, USA.
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35
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The Effects of Maximally Achievable Cycling Cadence on Carbohydrate Management at Moderate and Heavy Exercise Intensity. Int J Sports Physiol Perform 2018; 13:64-68. [PMID: 28459286 DOI: 10.1123/ijspp.2016-0555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Effects of different cycling cadences (revolutions/min [rpm]) on metabolic rate, blood lactate concentration (BLC), and reliance on carbohydrate (CHO) defined as the fraction of oxygen uptake used for CHO oxidation (relCHO) are highly individual. Whether this depends on the individually maximal achievable rpm obtained at minimized cycling resistance (rpmmax) is unknown. The authors tested the hypotheses that the individual freely chosen rpm in an incremental cycle-ergometer test (ILT) and relCHO at given BLC levels both depend on rpmmax. Seven master cyclists and 8 not specifically trained leisure athletes performed an ILT at individually freely chosen rpm and an rpmmax test. Respiratory data and BLC were measured; relCHO was plotted as a function of the BLC for the determinations of the individual BLC at relCHO of 75% and 95% (BLC75% and BLC95%). With 16.7%, the between-subjects variability of individual rpm was high but independent from rpmmax. In the master athletes, rpmmax explained 59.3% and 95.2% of BLC75% (P = .043) and BLC95% (P = .001), respectively. Irrespective of cycling experience, the individually preferred average rpm at submaximal stages of an ILT is highly variable and independent of rpmmax. In experienced cyclists, carbohydrate management defined as the ratio between substrate availability as indicated by BLC and relCHO depends on rpmmax.
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36
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Solli GS, Tønnessen E, Sandbakk Ø. The Training Characteristics of the World's Most Successful Female Cross-Country Skier. Front Physiol 2017; 8:1069. [PMID: 29326603 PMCID: PMC5741652 DOI: 10.3389/fphys.2017.01069] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/05/2017] [Indexed: 11/13/2022] Open
Abstract
The main aim of this study was to investigate the training characteristics of the most successful female cross-country skier ever during the best period of her career. The participant won six gold medals at the Olympic Games, 18 gold medals at the World Championship, and 110 World Cup victories. Day-to-day training diary data, interviews, and physiological tests were analyzed. Training data was systemized by training form (endurance, strength, and speed), intensity [low- (LIT), moderate- (MIT), and high-intensity training (HIT)], and mode (running, cycling, and skiing/roller skiing), followed by a division into different periodization phases. Specific sessions utilized in the various periodization periods and the day-to-day periodization of training, in connection with altitude camps and tapering toward major championships, were also analyzed. Following a 12-year nonlinear increase in training load, the annual training volume during the five consecutive successful years stabilized at 937 ± 25 h, distributed across 543 ± 9 sessions. During these 5 years, total training time was distributed as 90.6% endurance-, 8.0% strength-, and 1.4% speed-training, with endurance-training time consisting of 92.3 ± 0.3% LIT, 2.9 ± 0.5% MIT, and 4.8 ± 0.5% HIT. Total LIT-time consisted of 21% warm-up, 14% sessions <90 min, and 65% long-duration sessions >90 min. While the total number of LIT sessions remained stable across phases (32 sessions), total LIT-time was reduced from GP (76 h/month) to SP (68 h/month) and CP (55 h/month). MIT-time decreased from GP (2.8 h/month) to SP (2.2 h/month) and CP (1 h/month). HIT-time increased from GP (2.8 h/month) to SP (3.2 h/month) and CP (4.7 h/month). Altitude training accounted for 18-25% of annual training volume and performed across relatively short training camps (≤16 days) with a clear reduction of HIT training, but increased total and LIT volume compared to sea-level training. Training before international championships included a 2-week increase in LIT and strength volume followed by a gradual reduction of training volume and increased HIT during the last week. This study provides unique data on the world's most successful female cross-country skier's long-term training process, including novel information about the distribution of and interplay between sessions of different forms, intensities, and exercise modes throughout the annual season.
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Affiliation(s)
- Guro S Solli
- Department of Sports Science and Physical Education, Nord University, Bodø, Norway
| | | | - Øyvind Sandbakk
- Department of Neuromedicine and Movement Science, Centre for Elite Sports Research, Norwegian University of Science and Technology, Trondheim, Norway
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37
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Messias LHD, Gobatto CA, Beck WR, Manchado-Gobatto FB. The Lactate Minimum Test: Concept, Methodological Aspects and Insights for Future Investigations in Human and Animal Models. Front Physiol 2017. [PMID: 28642717 PMCID: PMC5463055 DOI: 10.3389/fphys.2017.00389] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In 1993, Uwe Tegtbur proposed a useful physiological protocol named the lactate minimum test (LMT). This test consists of three distinct phases. Firstly, subjects must perform high intensity efforts to induce hyperlactatemia (phase 1). Subsequently, 8 min of recovery are allowed for transposition of lactate from myocytes (for instance) to the bloodstream (phase 2). Right after the recovery, subjects are submitted to an incremental test until exhaustion (phase 3). The blood lactate concentration is expected to fall during the first stages of the incremental test and as the intensity increases in subsequent stages, to rise again forming a “U” shaped blood lactate kinetic. The minimum point of this curve, named the lactate minimum intensity (LMI), provides an estimation of the intensity that represents the balance between the appearance and clearance of arterial blood lactate, known as the maximal lactate steady state intensity (iMLSS). Furthermore, in addition to the iMLSS estimation, studies have also determined anaerobic parameters (e.g., peak, mean, and minimum force/power) during phase 1 and also the maximum oxygen consumption in phase 3; therefore, the LMT is considered a robust physiological protocol. Although, encouraging reports have been published in both human and animal models, there are still some controversies regarding three main factors: (1) the influence of methodological aspects on the LMT parameters; (2) LMT effectiveness for monitoring training effects; and (3) the LMI as a valid iMLSS estimator. Therefore, the aim of this review is to provide a balanced discussion between scientific evidence of the aforementioned issues, and insights for future investigations are suggested. In summary, further analyses is necessary to determine whether these factors are worthy, since the LMT is relevant in several contexts of health sciences.
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Affiliation(s)
| | | | - Wladimir R Beck
- Department of Physiological Sciences, Biological and Health Sciences Center, Federal University of São CarlosSão Paulo, Brazil
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Piucco T, Bini R, Sakaguchi M, Diefenthaeler F, Stefanyshyn D. Motor unit firing frequency of lower limb muscles during an incremental slide board skating test. Sports Biomech 2017. [PMID: 28632052 DOI: 10.1080/14763141.2016.1246600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This study investigated how the combination of workload and fatigue affected the frequency components of muscle activation and possible recruitment priority of motor units during skating to exhaustion. Ten male competitive speed skaters performed an incremental maximal test on a slide board. Activation of six muscles from the right leg was recorded throughout the test. A time-frequency analysis was performed to compute overall, high, and low frequency bands from the whole signal at 10, 40, 70, and 90% of total test time. Overall activation increased for all muscles throughout the test (p < 0.05 and ES > 0.80). There was an increase in low frequency (90 vs. 10%, p = 0.035, ES = 1.06) and a decrease in high frequency (90 vs. 10%, p = 0.009, ES = 1.38, and 90 vs. 40%, p = 0.025, ES = 1.12) components of gluteus maximus. Strong correlations were found between the maximal cadence and vastus lateralis, gluteus maximus and gluteus medius activation at the end of the test. In conclusion, the incremental skating test lead to an increase in activation of lower limb muscles, but only gluteus maximus was sensitive to changes in frequency components, probably caused by a pronounced fatigue.
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Affiliation(s)
- Tatiane Piucco
- a Faculty of Kinesiology, Roger Jackson Centre for Health and Wellness Research , University of Calgary , Calgary , Canada.,b Physical Education Department, Sports Centre , Federal University of Santa Catarina , Florianópolis , Brazil
| | - Rodrigo Bini
- c Centre of Physical Training of the Army , School of Physical Education of the Army , Rio de Janeiro , Brazil
| | - Masanori Sakaguchi
- a Faculty of Kinesiology, Roger Jackson Centre for Health and Wellness Research , University of Calgary , Calgary , Canada
| | - Fernando Diefenthaeler
- a Faculty of Kinesiology, Roger Jackson Centre for Health and Wellness Research , University of Calgary , Calgary , Canada.,b Physical Education Department, Sports Centre , Federal University of Santa Catarina , Florianópolis , Brazil
| | - Darren Stefanyshyn
- a Faculty of Kinesiology, Roger Jackson Centre for Health and Wellness Research , University of Calgary , Calgary , Canada
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Rezaei S, Agha-Alinejad H, Molanouri Shamsi M, Jafari M, Azevedo Voltarelli F, Naderi A, Earnest C. Evaluation of efforts in untrained Wistar rats following exercise on forced running wheel at maximal lactate steady state. J Exerc Nutrition Biochem 2017; 21:26-32. [PMID: 28712262 PMCID: PMC5508056 DOI: 10.20463/jenb.2017.0040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 02/09/2017] [Indexed: 11/23/2022] Open
Abstract
[Purpose] We aimed to examine the effect of running speed on metabolic responses associated with maximal lactate steady state (MLSS) in rats during forced running wheel (FRW) exercise.
[Methods] Forty male adult Wistar rats were divided into seven groups. The blood lactate threshold and peak running speed were determined for an incremental power test group. Five groups participated in constant power tests at intensities 10, 13, 14.5, 16, and 17.5 m/min to determine MLSS and a non-exercise group was chosen as the control. Animals were euthanized immediately after constant power tests and their corticosterone, non-esterified fatty acid (NEFA), blood glucose, and creatine kinase (CK) levels analyzed. The differences among groups were identified by one-way analysis of variance (p < 0.05).
[Results] Blood lactate threshold corresponded a running intensity of 15 m/min, while MLSS was determined to be 16 m/min. Serum corticosterone concentrations were significantly higher in 14.5, 16, and 17.5 m/min groups (298.8±62, 338.3±65, and 354±26 nM, respectively) as compared to that in the control group (210.6±16 nM). Concentrations of NEFA observed in groups 13, 14.5, 16, and 17.5 m/min (662.8±24, 702.35±69, 718.4±34, and 752.8±77 μM, respectively) were significantly higher than those in 10 m/min and control groups (511.1±53 and 412.1±56 μM, respectively). The serum CK concentration recorded for group 17.5 m/min (372.4±56 U/L) was higher than those recorded for other groups.
[Conclusion] The speed above 16 m/min on FRW resulted in increased physiological demands and muscle damage in untrained healthy Wistar rats.
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Affiliation(s)
- Sajjad Rezaei
- Physical Education & Sport Sciences Department, Faculty of Humanities, Tarbiat Modares University, Tehran, Iran
| | - Hamid Agha-Alinejad
- Physical Education & Sport Sciences Department, Faculty of Humanities, Tarbiat Modares University, Tehran, Iran
| | - Mahdieh Molanouri Shamsi
- Physical Education & Sport Sciences Department, Faculty of Humanities, Tarbiat Modares University, Tehran, Iran
| | - Mahvash Jafari
- Department of Biochemistry, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Fabricio Azevedo Voltarelli
- Graduation Program of Physical Education, Faculty of Physical Education, Federal University of Mato Grosso, Cuiabá, Brazil
| | - Alireza Naderi
- Department of Sport Physiology, Boroujerd Branch, Islamic Azad University, Boroujerd, Iran
| | - Conrad Earnest
- Exercise Science and Sport Nutrition, College Station, Texas A&M University, Texas, USA
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Pelarigo JG, Machado L, Fernandes RJ, Greco CC, Vilas-Boas JP. Oxygen uptake kinetics and energy system's contribution around maximal lactate steady state swimming intensity. PLoS One 2017; 12:e0167263. [PMID: 28245246 PMCID: PMC5330462 DOI: 10.1371/journal.pone.0167263] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 11/11/2016] [Indexed: 11/18/2022] Open
Abstract
The purpose of this study was to examine the oxygen uptake ( V˙O2) kinetics and the energy systems’ contribution at 97.5, 100 and 102.5% of the maximal lactate steady state (MLSS) swimming intensity. Ten elite female swimmers performed three-to-five 30 min submaximal constant swimming bouts at imposed paces for the determination of the swimming velocity (v) at 100%MLSS based on a 7 x 200 m intermittent incremental protocol until voluntary exhaustion to find the v associated at the individual anaerobic threshold. V˙O2 kinetics (cardiodynamic, primary and slow component phases) and the aerobic and anaerobic energy contributions were assessed during the continuous exercises, which the former was studied for the beginning and second phase of exercise. Subjects showed similar time delay (TD) (mean = 11.5–14.3 s) and time constant (τp) (mean = 13.8–16.3 s) as a function of v, but reduced amplitude of the primary component for 97.5% (35.7 ± 7.3 mL.kg.min-1) compared to 100 and 102.5%MLSS (41.0 ± 7.0 and 41.3 ± 5.4 mL.kg.min-1, respectively), and τp decreased (mean = 9.6–10.8 s) during the second phase of exercise. Despite the slow component did not occur for all swimmers at all swim intensities, when observed it tended to increase as a function of v. Moreover, the total energy contribution was almost exclusively aerobic (98–99%) at 97.5, 100 and 102.5%MLSS. We suggest that well-trained endurance swimmers with a fast TD and τp values may be able to adjust faster the physiological requirements to minimize the amplitude of the slow component appearance, parameter associated with the fatigue delay and increase in exhaustion time during performance, however, these fast adjustments were not able to control the progressive fatigue occurred slightly above MLSS, and most of swimmers reached exhaustion before 30min swam.
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Affiliation(s)
- Jailton Gregório Pelarigo
- University Catholic Center of Quixadá–UNICATÓLICA, Quixadá, Ceará, Brazil
- Metropolitan College of Grande Fortaleza–FAMETRO, Fortaleza, Ceará, Brazil
- Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, Porto, Portugal
- Porto Biomechanics Laboratory, LABIOMEP, University of Porto, Porto, Portugal
- * E-mail:
| | - Leandro Machado
- Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, Porto, Portugal
- Porto Biomechanics Laboratory, LABIOMEP, University of Porto, Porto, Portugal
| | - Ricardo Jorge Fernandes
- Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, Porto, Portugal
- Porto Biomechanics Laboratory, LABIOMEP, University of Porto, Porto, Portugal
| | - Camila Coelho Greco
- Human Performance Laboratory, Physical Education Department, São Paulo State University, Rio Claro, São Paulo, Brazil
| | - João Paulo Vilas-Boas
- Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, Porto, Portugal
- Porto Biomechanics Laboratory, LABIOMEP, University of Porto, Porto, Portugal
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Hall MM, Rajasekaran S, Thomsen TW, Peterson AR. Lactate: Friend or Foe. PM R 2017; 8:S8-S15. [PMID: 26972271 DOI: 10.1016/j.pmrj.2015.10.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 09/22/2015] [Accepted: 10/04/2015] [Indexed: 12/01/2022]
Abstract
Lactic acid has played an important role in the traditional theory of muscle fatigue and limitation of endurance exercise performance. It has been called a waste product of anaerobic metabolism and has been believed to be responsible for the uncomfortable "burn" of intense exercise and directly responsible for the metabolic acidosis of exercise, leading to decreased muscle contractility and ultimately cessation of exercise. Although this premise has been commonly taught, it is not supported by the scientific literature and has led to a great deal of confusion among the sports medicine and exercise science communities. This review will provide the sports medicine clinician with an understanding of contemporary lactate theories, including lactate's role in energy production, its contributions to metabolic acidosis, and its function as an energy substrate for a variety of tissues. Lactate threshold concepts will also be discussed, including a practical approach to understanding prediction of performance and monitoring of training progress based on these parameters.
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Affiliation(s)
- Mederic M Hall
- Department of Orthopaedics and Rehabilitation, University of Iowa Sports Medicine, 2701 Prairie Meadow Dr, Iowa City, IA 52242(∗).
| | - Sathish Rajasekaran
- Department of Orthopaedics and Rehabilitation, University of Iowa Sports Medicine, 2701 Prairie Meadow Dr, Iowa City, IA 52242(†)
| | - Timothy W Thomsen
- Department of Orthopaedics and Rehabilitation, University of Iowa Sports Medicine, 2701 Prairie Meadow Dr, Iowa City, IA 52242(‡)
| | - Andrew R Peterson
- Stead Family Department of Pediatrics, University of Iowa Sports Medicine, Iowa City, IA(¶)
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Peinado AB, Filho DP, Díaz V, Benito PJ, Álvarez-Sánchez M, Zapico AG, Calderón FJ. The midpoint between ventilatory thresholds approaches maximal lactate steady state intensity in amateur cyclists. Biol Sport 2016; 33:373-380. [PMID: 28090142 PMCID: PMC5143771 DOI: 10.5604/20831862.1221812] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/25/2016] [Accepted: 06/17/2016] [Indexed: 12/15/2022] Open
Abstract
The aim was to determine whether the midpoint between ventilatory thresholds (MPVT) corresponds to maximal lactate steady state (MLSS). Twelve amateur cyclists (21.0 ± 2.6 years old; 72.2 ± 9.0 kg; 179.8 ± 7.5 cm) performed an incremental test (25 W·min-1) until exhaustion and several constant load tests of 30 minutes to determine MLSS, on different occasions. Using MLSS determination as the reference method, the agreement with five other parameters (MPVT; first and second ventilatory thresholds: VT1 and VT2; respiratory exchange ratio equal to 1: RER = 1.00; and Maximum) was analysed by the Bland-Altman method. The difference between workload at MLSS and VT1, VT2, RER=1.00 and Maximum was 31.1 ± 20.0, -86.0 ± 18.3, -63.6 ± 26.3 and -192.3 ± 48.6 W, respectively. MLSS was underestimated from VT1 and overestimated from VT2, RER = 1.00 and Maximum. The smallest difference (-27.5 ± 15.1 W) between workload at MLSS and MPVT was in better agreement than other analysed parameters of intensity in cycling. The main finding is that MPVT approached the workload at MLSS in amateur cyclists, and can be used to estimate maximal steady state.
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Affiliation(s)
- A B Peinado
- Department of Health and Human Performance, Technical University of Madrid, Madrid, Spain
| | - Dm Pessôa Filho
- Department of Health and Human Performance, Technical University of Madrid, Madrid, Spain; College of Sciences, São Paulo State University (UNESP), Bauru (SP), Brazil
| | - V Díaz
- Department of Health and Human Performance, Technical University of Madrid, Madrid, Spain; Institute of Veterinary Physiology, University of Zurich, and Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
| | - P J Benito
- Department of Health and Human Performance, Technical University of Madrid, Madrid, Spain
| | - M Álvarez-Sánchez
- Department of Health and Human Performance, Technical University of Madrid, Madrid, Spain
| | - A G Zapico
- School of Education, Complutense University of Madrid, Madrid, Spain
| | - F J Calderón
- Department of Health and Human Performance, Technical University of Madrid, Madrid, Spain
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Pelarigo JG, Greco CC, Denadai BS, Fernandes RJ, Vilas-Boas JP, Pendergast DR. Do 5% changes around maximal lactate steady state lead to swimming biophysical modifications? Hum Mov Sci 2016; 49:258-66. [DOI: 10.1016/j.humov.2016.07.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 07/24/2016] [Accepted: 07/25/2016] [Indexed: 10/21/2022]
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Arratibel-Imaz I, Calleja-González J, Emparanza JI, Terrados N, Mjaanes JM, Ostojic SM. Lack of concordance amongst measurements of individual anaerobic threshold and maximal lactate steady state on a cycle ergometer. PHYSICIAN SPORTSMED 2016; 44:34-45. [PMID: 26578151 DOI: 10.1080/00913847.2016.1122501] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION The calculation of exertion intensity, in which a change is produced in the metabolic processes which provide the energy to maintain physical work, has been defined as the anaerobic threshold (AT). The direct calculation of maximal lactate steady state (MLSS) would require exertion intensities over a long period of time and with sufficient rest periods which would prove significantly difficult for daily practice. Many protocols have been used for the indirect calculation of MLSS. OBJECTIVES The aim of this study is to determine if the results of measurements with 12 different AT calculation methods and calculation software [Keul, Simon, Stegmann, Bunc, Dickhuth (TKM and WLa), Dmax, Freiburg, Geiger-Hille, Log-Log, Lactate Minimum] can be used interchangeably, including the method of the fixed threshold of Mader/OBLA's 4 mmol/l and then to compare them with the direct measurement of MLSS. METHODS There were two parts to this research. Phase 1: results from 162 exertion tests chosen at random from the 1560 tests. Phase 2: sixteen athletes (n = 16) carried out different tests on five consecutive days. RESULTS There was very high concordance among all the methods [intraclass correlation coefficient (ICC) > 0.90], except Log-Log in relation to the Stegamnn, Dmax, Dickhuth-WLa and Geiger-Hille. The Dickhuth-TKM showed a high tendency towards concordance, with Dmax (2.2 W) and Dickhuth-WLa (0.1 W). The Dickhuth-TKM method presented a high tendency to concordance with Dickhuth-WLa (0.5 W), Freiburg (7.4 W), MLSS (2.0 W), Bunc (8.9 W), Dmax (0.1 W). The calculation of MLSS power showed a high tendency to concordance, with Dickhuth-TKM (2 W), Dmax (2.1 W), Dickhuth-WLa (1.5 W). CONCLUSION The fixed threshold of 4 mmol/l or OBLA produces slightly different and higher results than those obtained with all the methods analyzed, including MLSS, meaning an overestimation of power in the individual anaerobic threshold. The Dickhuth-TKM, Dmax and Dickhuth-WLa methods defined a high concordance on a cycle ergometer. Dickhuth-TKM, Dmax, Dickhuth-WLa described a high concordance with the power calculated to know the MLSS.
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Affiliation(s)
- Iñaki Arratibel-Imaz
- a Department of Physical Education and Sport , Faculty of Sport Sciences, University of Basque Country , Vitoria-Gasteiz , Spain
| | - Julio Calleja-González
- a Department of Physical Education and Sport , Faculty of Sport Sciences, University of Basque Country , Vitoria-Gasteiz , Spain
| | - Jose Ignacio Emparanza
- b Epidemiology and Public Health, CIBER-ESP, IIS BioDonostia , University Hospital Donostia , Donostia , Spain
| | - Nicolas Terrados
- c Sports Medicine Regional Unit of Asturias-FDM Aviles and Department of Functional Biology , University of Oviedo , Oviedo , Spain
| | - Jeffrey M Mjaanes
- d Regional Department of Orthopedic Surgery and Pediatrics, Midwest Orthopedics at Rush , Rush University Medical Center , Chicago , IL , USA
| | - Sergej M Ostojic
- e Faculty of Sport and Physical Education , University of Novi Sad , Novi Sad , Serbia
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Pallarés JG, Morán-Navarro R, Ortega JF, Fernández-Elías VE, Mora-Rodriguez R. Validity and Reliability of Ventilatory and Blood Lactate Thresholds in Well-Trained Cyclists. PLoS One 2016; 11:e0163389. [PMID: 27657502 PMCID: PMC5033582 DOI: 10.1371/journal.pone.0163389] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 09/06/2016] [Indexed: 11/18/2022] Open
Abstract
PURPOSE The purpose of this study was to determine, i) the reliability of blood lactate and ventilatory-based thresholds, ii) the lactate threshold that corresponds with each ventilatory threshold (VT1 and VT2) and with maximal lactate steady state test (MLSS) as a proxy of cycling performance. METHODS Fourteen aerobically-trained male cyclists ([Formula: see text] 62.1±4.6 ml·kg-1·min-1) performed two graded exercise tests (50 W warm-up followed by 25 W·min-1) to exhaustion. Blood lactate, [Formula: see text] and [Formula: see text] data were collected at every stage. Workloads at VT1 (rise in [Formula: see text];) and VT2 (rise in [Formula: see text]) were compared with workloads at lactate thresholds. Several continuous tests were needed to detect the MLSS workload. Agreement and differences among tests were assessed with ANOVA, ICC and Bland-Altman. Reliability of each test was evaluated using ICC, CV and Bland-Altman plots. RESULTS Workloads at lactate threshold (LT) and LT+2.0 mMol·L-1 matched the ones for VT1 and VT2, respectively (p = 0.147 and 0.539; r = 0.72 and 0.80; Bias = -13.6 and 2.8, respectively). Furthermore, workload at LT+0.5 mMol·L-1 coincided with MLSS workload (p = 0.449; r = 0.78; Bias = -4.5). Lactate threshold tests had high reliability (CV = 3.4-3.7%; r = 0.85-0.89; Bias = -2.1-3.0) except for DMAX method (CV = 10.3%; r = 0.57; Bias = 15.4). Ventilatory thresholds show high reliability (CV = 1.6%-3.5%; r = 0.90-0.96; Bias = -1.8-2.9) except for RER = 1 and V-Slope (CV = 5.0-6.4%; r = 0.79; Bias = -5.6-12.4). CONCLUSIONS Lactate threshold tests can be a valid and reliable alternative to ventilatory thresholds to identify the workloads at the transition from aerobic to anaerobic metabolism.
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Affiliation(s)
- Jesús G. Pallarés
- University of Castilla-La Mancha, Exercise Physiology Laboratory at Toledo, Toledo, Spain
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, Spain
| | - Ricardo Morán-Navarro
- University of Castilla-La Mancha, Exercise Physiology Laboratory at Toledo, Toledo, Spain
- Human Performance and Sports Science Laboratory, Faculty of Sport Sciences, University of Murcia, Murcia, Spain
| | - Juan Fernando Ortega
- University of Castilla-La Mancha, Exercise Physiology Laboratory at Toledo, Toledo, Spain
| | | | - Ricardo Mora-Rodriguez
- University of Castilla-La Mancha, Exercise Physiology Laboratory at Toledo, Toledo, Spain
- * E-mail:
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Abreu P, Mendes SVD, Leal-Cardoso JH, Ceccatto VM. Anaerobic threshold employed on exercise training prescription and performance assessment for laboratory rodents: A short review. Life Sci 2016; 151:1-6. [DOI: 10.1016/j.lfs.2016.02.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 01/08/2023]
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Zagatto AM, Padulo J, Silva ARSD, Müller PDTG, Miyagi WE, Gobatto CA. Physiological responses at the lactate-minimum-intensity with and without prior high-intensity exercise. J Sports Sci 2016; 34:2106-13. [PMID: 26928746 DOI: 10.1080/02640414.2016.1151921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This study examined the physiological responses during exercise-to-exhaustion at the lactate-minimum-intensity with and without prior high-intensity exercise. Eleven recreationally trained males performed a graded exercise test, a lactate minimum test and two constant-load tests at lactate-minimum-intensity until exhaustion, which were applied with or without prior hyperlactatemia induction (i.e., 30-s Wingate test). The physiological responses were significantly different (P < 0.05) between constant-load tests for pulmonary ventilation ([Formula: see text]), blood-lactate-concentration ([La(-)]), pH, bicarbonate concentration ([HCO3]) and partial pressure of carbon dioxide during the initial minutes. The comparisons within constant-load tests showed steady state behaviour for oxygen uptake and the respiratory exchange ratio, but heart rate and rating of perceived exertion increased significantly during both exercise conditions, while the [Formula: see text] increased only during constant-load effort. During effort performed after high-intensity exercise: [Formula: see text], [La(-)], pH and [HCO3] differed at the start of exercise compared to another condition but were similar at the end (P > 0.05). In conclusion, the constant-load exercises performed at lactate-minimum-intensity with or without prior high-intensity exercise did not lead to the steady state of all analysed parameters; however, variables such as [La(-)], pH and [HCO3] - altered at the beginning of effort performed after high-intensity exercise - were reestablished after approximately 30 min of exercise.
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Affiliation(s)
| | | | - Adelino Ramos Sanchez da Silva
- c School of Physical Education and Sports of Ribeirão Preto , University of São Paulo (USP) , Ribeirão Preto , SP , Brazil
| | - Paulo de Tarso Guerrero Müller
- d Laboratory of Respiratory Pathophysiology (LAFIR), Federal University of Mato Grosso do Sul (UFMS) , Campo Grande , MS , Brazil
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L-Lactate-selective microbial sensor based on flavocytochrome b2-enriched yeast cells using recombinant and nanotechnology approaches. Talanta 2015; 144:1195-200. [DOI: 10.1016/j.talanta.2015.07.081] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/23/2015] [Accepted: 07/28/2015] [Indexed: 11/21/2022]
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Abstract
Speed skating is an intriguing sport to study from different perspectives due to the peculiar way of motion and the multiple determinants for performance. This review aimed to identify what is known on (long-track) speed skating, and which individual characteristics determine speed skating performance. A total of 49 studies were included. Based on a multidimensional performance model, person-related performance characteristics were categorized in anthropometrical, technical, physiological, tactical, and psychological characteristics. Literature was found on anthropometry, technique, physiology, and tactics. However, psychological studies were clearly under-represented. In particular, the role of self-regulation might deserve more attention to further understand mechanisms relevant for optimal performance and for instance pacing. Another remarkable finding was that the technically/biomechanically favourable crouched skating technique (i.e. small knee and trunk angle) leads to a physiological disadvantage: a smaller knee angle may increase the deoxygenation of the working muscles. This is an important underlying aspect for the pacing tactics in speed skating. Elite speed skaters need to find the optimal balance between obtaining a fast start and preventing negative technical adaptations later on in the race by distributing their available energy over the race in an optimal way. More research is required to gain more insight into how this impacts on the processes of fatigue and coordination during speed skating races. This can lead to a better understanding on how elite speed skaters can maintain the optimal technical characteristics throughout the entire race, and how they can adapt their pacing to optimize all identified aspects that determine performance.
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50
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Cristi-Montero C, Rodriguez-Rodriguez F, Mendoza-Muñoz J, Baronti-Correa F, Leiva-Olivares S, Rojas-Hube M, Bresciani G. Blood lactate removal after a rowing all-out test depends on the active protocol proposed. Sci Sports 2015. [DOI: 10.1016/j.scispo.2014.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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