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Gløersen Ø, Viken Å, Lund-Hansen M, Losnegard T. The influence of race duration on oxygen demand, uptake and deficit in competitive cross-country skiers. Eur J Appl Physiol 2024:10.1007/s00421-024-05531-1. [PMID: 38918220 DOI: 10.1007/s00421-024-05531-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 06/11/2024] [Indexed: 06/27/2024]
Abstract
PURPOSE To measure oxygen demand, uptake, and deficits in competitive cross-country skiers during outdoor roller skiing at different competition durations, ranging from the endurance domain to the sprint domain. METHODS Ten competitive cross-country skiers (6 males; V ˙ O2max 78 ± 3 and 4 females; V ˙ O2max 62 ± 3 mL∙kg-1∙min-1) raced time trials consisting of 1, 2, and 4 laps in a 1.6 km racecourse in a randomized order with 35 min recovery in-between. Oxygen uptake was measured using a wearable metabolic system while oxygen demand was estimated from kinematic data (GPS and IMU) and an athlete-specific model of skiing economy. Skiing economy and V ˙ O2max was established on a separate test day using six submaximal constant-load trials at different speeds and inclines, and one maximal-effort trial on a roller-skiing treadmill. RESULTS Average oxygen demand was 112 ± 8%, 103 ± 7% and 98 ± 7% of V ˙ O2max during the 1 (3:37 ± 0:20 m:ss), 2 (7:36 ± 0:38 m:ss) and 4 (15:43 ± 1:26 m:ss) lap time trials, respectively, and appeared to follow an inverse relationship with time-trial duration. Average oxygen uptake was unaffected by race length (86 ± 5%, 86 ± 5%, and 86 ± 7% of V ˙ O2max, respectively). Accumulated oxygen deficit at the end of each time trial was 85 ± 13, 106 ± 32 and 158 ± 62 mL∙kg-1, while oxygen deficits per work bout was 23 ± 3, 18 ± 3 and 16 ± 3 mL∙kg-1 for the 1, 2, and 4-lap time trials, respectively. CONCLUSION Elite cross-country skiers adjust their pacing strategies from attaining relatively small oxygen deficits per work bout in the endurance domain, to larger deficits in the sprint domain. This indicates a shift in strategy from prioritizing stable work-economy and rate-of-recovery in the endurance domain, to maximizing power output in the sprint domain.
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Affiliation(s)
- Øyvind Gløersen
- Department of Health Research, SINTEF Digital, Postboks 124 Blindern, 0314, Oslo, Norway.
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway.
| | - Ånung Viken
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Magne Lund-Hansen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Thomas Losnegard
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
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Talsnes RK, Berdal T, Brattebø JM, Seeberg T, Losnegard T, Kocbach J, Sandbakk Ø. Comprehensive analysis of performance, physiological, and perceptual responses during an entire sprint cross-country skiing competition. Eur J Appl Physiol 2024; 124:1015-1025. [PMID: 37804364 PMCID: PMC10879232 DOI: 10.1007/s00421-023-05326-w] [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: 08/01/2023] [Accepted: 09/14/2023] [Indexed: 10/09/2023]
Abstract
PURPOSE To investigate performance, physiological, and perceptual responses of an entire sprint cross-country skiing competition in the skating style. METHODS Eighteen national-level male junior skiers participated in a simulated competition comprising an individual time trial (TT), followed by three heats (quarterfinals [QF], semifinals [SF], and final [F]). Participants' heart rate (HR) was continuously monitored while perceived readiness (RED, 1-10), rating of perceived exertion (RPE, 6-20), and blood lactate [La-] were assessed at standardized time points. RESULTS The total duration and distance covered were 03:30 ± 00:06 h and 25.2 ± 2.9 km, respectively. The participants spent 02:19 ± 00:27 h > 60% of their maximal HR (HRmax) and 00:16 ± 00:04 h > 85% of HRmax. Average HR decreased from TT to F (89.3 ± 2.0% vs. 86.9 ± 3.0% of HRmax, P < 0.01). [La-] levels were highest before (4.6 ± 2.0 vs. 2.9 ± 1.2, 3.2 ± 2.0 and 2.5 ± 1.3 mmol·L-1, all P < 0.01) and after (10.8 ± 1.4 vs. 9.8 ± 1.6, 9.1 ± 1.8 and 8.7 ± 1.7 mmol·L-1, all P < 0.05) F compared to TT, QF, and SF, respectively. RED was lowest before F compared to TT, QF, and SF (6.6 ± 1.4 vs. 7.9 ± 1.1, 7.6 ± 1.1, and 7.4 ± 1.4, respectively, all P < 0.05) while RPE was highest after TT compared to QF, SF, and F (17.8 ± 0.9 vs. 15.1 ± 2.0, 16.5 ± 1.2 and 16.6 ± 1.8, respectively, all P < 0.01). The six best-performing skiers demonstrated higher RED before F (7.2 ± 0.9 vs. 5.3 ± 1.2, P < 0.05) and higher [La-] after F (11.2 ± 0.2 vs. 10.2 ± 0.3, mmol·L-1, P < 0.05) than lower-performing competitors. CONCLUSION This study provides novel insights into physiological demands of an entire sprint cross-country skiing competition, which involves repeated 3-min high-intensity efforts interspersed with > 2 h (25 km) of low- to moderate-intensity exercise.
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Affiliation(s)
- Rune Kjøsen Talsnes
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway.
| | - Tore Berdal
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jan-Magnus Brattebø
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Trine Seeberg
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Thomas Losnegard
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Jan Kocbach
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Øyvind Sandbakk
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
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Staunton CA, Sloof L, Brandts M, Jonsson Kårström M, Laaksonen MS, Björklund G. The Effect of Rifle Carriage on the Physiological and Accelerometer Responses During Biathlon Skiing. Front Sports Act Living 2022; 4:813784. [PMID: 35399594 PMCID: PMC8990322 DOI: 10.3389/fspor.2022.813784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 03/02/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose Investigate the effect of biathlon rifle carriage on physiological and accelerometer-derived responses during biathlon skiing. Methods Twenty-eight biathletes (11F, 17M) completed two XC skiing time-trials (~2,300 m), once with and once without the biathlon rifle, with concurrent measurements of HR, skiing speed and accelerations recorded from three triaxial accelerometers attached at the Upper-spine, Lower-spine and Pelvis. Exercise intensity was quantified from HR, skiing speed as well from accelerometry-derived PlayerLoad™ per minute (PL·min-1) and average net force (AvFNet). All metrics were analyzed during Uphill, Flat and Downhill sections of the course. Relationships between accelerometry-derived metrics and skiing speed were examined. Results Time-trials were faster for males compared with females (mean difference: 97 ± 73 s) and No-Rifle compared to With-Rifle (mean difference: 16 ± 9 s). HR was greatest during Downhill (183 ± 5 bpm), followed by Uphill (181 ± 5 bpm) and was lowest in the Flat sections (177 ± 6 bpm, p <0.05). For PL·min-1 and AvFNet there were 3-way Rifle x Gradient x Sensor-Position interactions. Typically, these metrics were greatest during Uphill and Flat sections and were lowest during Downhill sections. Rifle carriage had no impact on the AvFNet at the Lower-Spine or Pelvis. Significant positive linear relationships were identified between skiing speed and accelerometer-derived metrics during Uphill, Flat and Downhill skiing (r = 0.12-0.61, p < 0.05). Conclusions The accelerometry-derived approach used in this study provides the potential of a novel method of monitoring the external demands during skiing. In particular, AvFNet with sensors located close to the center of mass displayed greatest utility because it followed the expected response of external intensity where responses were greatest during uphill sections, followed by flats and lowest during downhills. In addition, there were significant positive relationships between AvFNet and skiing speed ranging from small to large. Accelerometry-derived measures could provide useful estimates of the external demands in XC skiing and biathlon.
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Affiliation(s)
- Craig A Staunton
- Swedish Winter Sports Research Centre, Faculty of Human Sciences, Mid Sweden University, Östersund, Sweden
| | - Luciën Sloof
- Swedish Winter Sports Research Centre, Faculty of Human Sciences, Mid Sweden University, Östersund, Sweden
| | - Maxime Brandts
- Swedish Winter Sports Research Centre, Faculty of Human Sciences, Mid Sweden University, Östersund, Sweden.,Institute of Sports Science, Saarland University, Saarbrücken, Germany
| | - Malin Jonsson Kårström
- Swedish Winter Sports Research Centre, Faculty of Human Sciences, Mid Sweden University, Östersund, Sweden
| | - Marko S Laaksonen
- Swedish Winter Sports Research Centre, Faculty of Human Sciences, Mid Sweden University, Östersund, Sweden
| | - Glenn Björklund
- Swedish Winter Sports Research Centre, Faculty of Human Sciences, Mid Sweden University, Östersund, Sweden
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Heart Rate Does Not Accurately Predict Metabolic Intensity During Variable-Intensity Roller Skiing or Cycling. Int J Sports Physiol Perform 2022; 17:1664-1671. [DOI: 10.1123/ijspp.2022-0114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 07/26/2022] [Accepted: 08/01/2022] [Indexed: 11/09/2022]
Abstract
Purpose: To critically appraise the utility of heart rate (HR) and power output (PO) to predict metabolic rate (MR) and oxygen consumption () during variable-intensity roller skiing and cycling. Methods: National-level cyclists (n = 8) and cross-country skiers (n = 9) completed a preliminary session to determine , and a variable-intensity protocol with 3 high-intensity stages at 90% for 3 minutes interspersed with 3 moderate-intensity stages at 70% for 6 minutes. Cardiorespiratory measures were recorded throughout. Linear HR–MR, , PO–MR, and regressions were computed from the preliminary session, individually, for all athletes and used to predict MR and from both HR and PO, separately, during the variable-intensity protocol. Mean differences with 95% limits of agreement (LOA) between measured and predicted MR and were calculated. Results: MR and estimated from HR displayed a mean bias close to zero but wide LOA. HR overestimated MR and during moderate intensity but underestimated MR and during high intensity, for both roller skiing and cycling. MR and estimated from PO were more consistent across the experimental trial, displaying a mean bias farther from zero but with tighter LOA. Conclusions: This study has demonstrated that HR has limited utility to predict metabolic intensity during variable-intensity roller skiing and cycling because of wide LOA. On the other hand, metabolic intensity predicted from PO had tighter LOA, suggesting better consistency. PO might provide a better prediction of metabolic intensity compared with HR, particularly when longer-duration steps are performed during preliminary testing.
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Seeberg TM, Kocbach J, Danielsen J, Noordhof DA, Skovereng K, Haugnes P, Tjønnås J, Sandbakk Ø. Physiological and Biomechanical Determinants of Sprint Ability Following Variable Intensity Exercise When Roller Ski Skating. Front Physiol 2021; 12:638499. [PMID: 33841176 PMCID: PMC8027482 DOI: 10.3389/fphys.2021.638499] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 03/05/2021] [Indexed: 11/16/2022] Open
Abstract
The most common race format in cross-country (XC) skiing is the mass-start event, which is under-explored in the scientific literature. To explore factors important for XC skiing mass-starts, the main purpose of this study was to investigate physiological and biomechanical determinants of sprint ability following variable intensity exercise when roller ski skating. Thirteen elite male XC skiers performed a simulated mass-start competition while roller ski skating on a treadmill. The protocol consisted of an initial 21-min bout with a varying track profile, designed as a competition track with preset inclines and speeds, directly followed by an all-out sprint (AOS) with gradually increased speed to rank their performance. The initial part was projected to simulate the “stay-in-the-group” condition during a mass-start, while the AOS was designed to assess the residual physiological capacities required to perform well during the final part of a mass-start race. Cardiorespiratory variables, kinematics and pole forces were measured continuously, and the cycles were automatically detected and classified into skating sub-techniques through a machine learning model. Better performance ranking was associated with higher VO2Max (r = 0.68) and gross efficiency (r = 0.70) measured on separate days, as well as the ability to ski on a lower relative intensity [i.e., %HRMax (r = 0.87), %VO2Max (r = 0.89), and rating of perceived exertion (r = 0.73)] during the initial 21-min of the simulated mass-start (all p-values < 0.05). Accordingly, the ability to increase HR (r = 0.76) and VO2 (r = 0.72), beyond the corresponding values achieved during the initial 21-min, in the AOS correlated positively with performance (both p < 0.05). In addition, greater utilization of the G3 sub-technique in the steepest uphill (r = 0.69, p < 0.05), as well as a trend for longer cycle lengths (CLs) during the AOS (r = 0.52, p = 0.07), were associated with performance. In conclusion, VO2Max and gross efficiency were the most significant performance-determining variables of simulated mass-start performance, enabling lower relative intensity and less accumulation of fatigue before entering the final AOS. Subsequently, better performance ranking was associated with more utilization of the demanding G3 sub-technique in the steepest uphill, and physiological reserves allowing better-performing skiers to utilize a larger portion of their aerobic potential and achieve longer CLs and higher speed during the AOS.
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Affiliation(s)
- Trine M Seeberg
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway.,Smart Sensor Systems, SINTEF Digital, Oslo, Norway
| | - Jan Kocbach
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jørgen Danielsen
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Dionne A Noordhof
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Knut Skovereng
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Pål Haugnes
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
| | | | - Øyvind Sandbakk
- Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
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Andersson EP, Noordhof DA, Lögdal N. The Anaerobic Capacity of Cross-Country Skiers: The Effect of Computational Method and Skiing Sub-technique. Front Sports Act Living 2020; 2:37. [PMID: 33345029 PMCID: PMC7739726 DOI: 10.3389/fspor.2020.00037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/20/2020] [Indexed: 11/13/2022] Open
Abstract
Anaerobic capacity is an important performance-determining variable of sprint cross-country skiing. Nevertheless, to date, no study has directly compared the anaerobic capacity, determined using the maximal accumulated oxygen deficit (MAOD) method and gross efficiency (GE) method, while using different skiing sub-techniques. Purpose: To compare the anaerobic capacity assessed using two different MAOD approaches (including and excluding a measured y-intercept) and the GE method during double poling (DP) and diagonal stride (DS) cross-country skiing. Methods: After an initial familiarization trial, 16 well-trained male cross-country skiers performed, in each sub-technique on separate occasions, a submaximal protocol consisting of eight 4-min bouts at intensities between ~47–78% of V.O2peak followed by a 4-min roller-skiing time trial, with the order of sub-technique being randomized. Linear and polynomial speed-metabolic rate relationships were constructed for both sub-techniques, while using a measured y-intercept (8+YLIN and 8+YPOL) or not (8–YLIN and 8–YPOL), to determine the anaerobic capacity using the MAOD method. The average GE (GEAVG) of all eight submaximal exercise bouts or the GE of the last submaximal exercise bout (GELAST) were used to calculate the anaerobic capacity using the GE method. Repeated measures ANOVA were used to test differences in anaerobic capacity between methods/approaches. Results: A significant interaction was found between computational method and skiing sub-technique (P < 0.001, η2 = 0.51) for the anaerobic capacity estimates. The different methodologies resulted in significantly different anaerobic capacity values in DP (P < 0.001, η2 = 0.74) and in DS (P = 0.016, η2 = 0.27). The 8-YPOL model resulted in the smallest standard error of the estimate (SEE, 0.24 W·kg−1) of the MAOD methods in DP, while the 8-YLIN resulted in a smaller SEE value than the 8+YLIN model (0.17 vs. 0.33 W·kg−1) in DS. The 8-YLIN and GELAST resulted in the closest agreement in anaerobic capacity values in DS (typical error 2.1 mL O2eq·kg−1). Conclusions: It is discouraged to use the same method to estimate the anaerobic capacity in DP and DS sub-techniques. In DP, a polynomial MAOD method (8-YPOL) seems to be the preferred method, whereas the 8-YLIN, GEAVG, and GELAST can all be used for DS, but not interchangeable, with GELAST being the least time-consuming method.
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Affiliation(s)
- Erik P Andersson
- Department of Health Sciences, Swedish Winter Sports Research Centre, Mid Sweden University, Östersund, Sweden
| | - Dionne A Noordhof
- Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Science, Centre for Elite Sports Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Nestor Lögdal
- Department of Health Sciences, Swedish Winter Sports Research Centre, Mid Sweden University, Östersund, Sweden
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Losnegard T. Energy system contribution during competitive cross-country skiing. Eur J Appl Physiol 2019; 119:1675-1690. [PMID: 31076890 PMCID: PMC6647095 DOI: 10.1007/s00421-019-04158-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 05/03/2019] [Indexed: 10/28/2022]
Abstract
Energy system contribution during cross-country (XC) skiing races is dependent on several factors, including the race duration, track profile, and sub-techniques applied, and their subsequent effects on the use of the upper and lower body. This review provides a scientific synopsis of the interactions of energy system contributions from a physiological, technical, and tactical perspective. On average, the aerobic proportion of the total energy expended during XC skiing competitions is comparable to the values for other sports with similar racing times. However, during both sprint (≤ 1.8 km) and distance races (≥ 10 and 15 km, women and men, respectively) a high aerobic turnover interacts with subsequent periods of very high work rates at ~ 120 to 160% of VO2peak during the uphill sections of the race. The repeated intensity fluctuations are possible due to the nature of skiing, which involves intermittent downhills where skiers can recover. Thus, the combination of high and sustained aerobic energy turnover and repeated work rates above VO2peak, interspersed with short recovery periods, distinguishes XC skiing from most other endurance sports. The substantially increased average speed in races over recent decades, frequent competitions in mass starts and sprints, and the greater importance of short periods at high speeds in various sub-techniques, have demanded changes in the physiological, technical, and tactical abilities needed to achieve world-class level within the specific disciplines.
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Affiliation(s)
- Thomas Losnegard
- Department of Physical Performance, Norwegian School of Sport Sciences, Ullevål Stadion, Post box 4014, 0806, Oslo, Norway.
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Oskarsson J, McGawley K. No individual or combined effects of caffeine and beetroot-juice supplementation during submaximal or maximal running. Appl Physiol Nutr Metab 2018; 43:697-703. [DOI: 10.1139/apnm-2017-0547] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Dietary supplements such as caffeine and beetroot juice are used by athletes in an attempt to optimize performance and therefore gain an advantage in competition. The aim of this study was to investigate the individual and combined effects of caffeine and beetroot-juice supplementation during submaximal and maximal treadmill running. Seven males (maximal oxygen uptake: 59.0 ± 2.9 mL·kg–1·min–1) and 2 females (maximal oxygen uptake: 53.1 ± 11.4 mL·kg–1·min–1) performed a preliminary trial followed by 4 experimental test sessions. Each test session consisted of two 5-min submaximal running bouts (at ∼70% and 80% of maximal oxygen uptake) and a maximal 1-km time trial (TT) in a laboratory. Participants ingested 70 mL of concentrated beetroot juice containing either 7.3 mmol of nitrate (BR) or no nitrate (PBR) 2.5 h prior to each test session, then either caffeine (C) at 4.8 ± 0.4 (4.3–5.6) mg/kg of body mass or a caffeine placebo (PC) 45 min before each test session. The 4 test sessions (BR-C, BR-PC, PBR-C, and PBR-PC) were presented in a counterbalanced and double-blind manner. No significant differences were identified between the 4 interventions regarding relative oxygen uptake, running economy, respiratory exchange ratio, heart rate (HR), or rating of perceived exertion (RPE) at the 2 submaximal intensities (P > 0.05). Moreover, there were no significant differences in performance, maximum HR, peak blood lactate concentration, or RPE during the maximal TT when comparing the interventions (P > 0.05). In conclusion, no beneficial effects of supplementing with typical doses of caffeine, beetroot juice, or a combination of the two were observed for physiological, perceptual, or performance responses during submaximal or maximal treadmill running exercise.
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Affiliation(s)
- Johanna Oskarsson
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 831 25 Östersund, Sweden
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 831 25 Östersund, Sweden
| | - Kerry McGawley
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 831 25 Östersund, Sweden
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 831 25 Östersund, Sweden
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Andersson EP, McGawley K. A Comparison between Different Methods of Estimating Anaerobic Energy Production. Front Physiol 2018; 9:82. [PMID: 29472871 PMCID: PMC5809502 DOI: 10.3389/fphys.2018.00082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 01/23/2018] [Indexed: 12/02/2022] Open
Abstract
Purpose: The present study aimed to compare four methods of estimating anaerobic energy production during supramaximal exercise. Methods: Twenty-one junior cross-country skiers competing at a national and/or international level were tested on a treadmill during uphill (7°) diagonal-stride (DS) roller-skiing. After a 4-minute warm-up, a 4 × 4-min continuous submaximal protocol was performed followed by a 600-m time trial (TT). For the maximal accumulated O2 deficit (MAOD) method the V.O2-speed regression relationship was used to estimate the V.O2 demand during the TT, either including (4+Y, method 1) or excluding (4-Y, method 2) a fixed Y-intercept for baseline V.O2. The gross efficiency (GE) method (method 3) involved calculating metabolic rate during the TT by dividing power output by submaximal GE, which was then converted to a V.O2 demand. An alternative method based on submaximal energy cost (EC, method 4) was also used to estimate V.O2 demand during the TT. Results: The GE/EC remained constant across the submaximal stages and the supramaximal TT was performed in 185 ± 24 s. The GE and EC methods produced identical V.O2 demands and O2 deficits. The V.O2 demand was ~3% lower for the 4+Y method compared with the 4-Y and GE/EC methods, with corresponding O2 deficits of 56 ± 10, 62 ± 10, and 63 ± 10 mL·kg−1, respectively (P < 0.05 for 4+Y vs. 4-Y and GE/EC). The mean differences between the estimated O2 deficits were −6 ± 5 mL·kg−1 (4+Y vs. 4-Y, P < 0.05), −7 ± 1 mL·kg−1 (4+Y vs. GE/EC, P < 0.05) and −1 ± 5 mL·kg−1 (4-Y vs. GE/EC), with respective typical errors of 5.3, 1.9, and 6.0%. The mean difference between the O2 deficit estimated with GE/EC based on the average of four submaximal stages compared with the last stage was 1 ± 2 mL·kg−1, with a typical error of 3.2%. Conclusions: These findings demonstrate a disagreement in the O2 deficits estimated using current methods. In addition, the findings suggest that a valid estimate of the O2 deficit may be possible using data from only one submaximal stage in combination with the GE/EC method.
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Affiliation(s)
- Erik P Andersson
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden
| | - Kerry McGawley
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden
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10
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Stöggl TL, Björklund G. High Intensity Interval Training Leads to Greater Improvements in Acute Heart Rate Recovery and Anaerobic Power as High Volume Low Intensity Training. Front Physiol 2017; 8:562. [PMID: 28824457 PMCID: PMC5539186 DOI: 10.3389/fphys.2017.00562] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/18/2017] [Indexed: 11/13/2022] Open
Abstract
The purpose of the current study was to explore if training regimes utilizing diverse training intensity distributions result in different responses on neuromuscular status, anaerobic capacity/power and acute heart rate recovery (HRR) in well-trained endurance athletes. Methods: Thirty-six male (n = 33) and female (n = 3) runners, cyclists, triathletes and cross-country skiers [peak oxygen uptake: (VO2peak): 61.9 ± 8.0 mL·kg−1·min−1] were randomly assigned to one of three groups (blocked high intensity interval training HIIT; polarized training POL; high volume low intensity oriented control group CG/HVLIT applying no HIIT). A maximal anaerobic running/cycling test (MART/MACT) was performed prior to and following a 9-week training period. Results: Only the HIIT group achieved improvements in peak power/velocity (+6.4%, P < 0.001) and peak lactate (P = 0.001) during the MART/MACT, while, unexpectedly, in none of the groups the performance at the established lactate concentrations (4, 6, 10 mmol·L−1) was changed (P > 0.05). Acute HRR was improved in HIIT (11.2%, P = 0.002) and POL (7.9%, P = 0.023) with no change in the HVLIT oriented control group. Conclusion: Only a training regime that includes a significant amount of HIIT improves the neuromuscular status, anaerobic power and the acute HRR in well-trained endurance athletes. A training regime that followed more a low and moderate intensity oriented model (CG/HVLIT) had no effect on any performance or HRR outcomes.
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Affiliation(s)
- Thomas L Stöggl
- Department of Sport Science and Kinesiology, University of SalzburgSalzburg, Austria
| | - Glenn Björklund
- Department of Health Sciences, Sports Tech Research Centre, Mid Sweden UniversityÖstersund, Sweden.,The Swedish Sports ConfederationStockholm, Sweden
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11
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Björklund G, Holmberg HC, Stöggl T. The effects of prior high intensity double poling on subsequent diagonal stride skiing characteristics. SPRINGERPLUS 2015; 4:40. [PMID: 25713756 PMCID: PMC4330244 DOI: 10.1186/s40064-015-0796-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 01/05/2015] [Indexed: 11/10/2022]
Abstract
PURPOSE To investigate the influence of prior high intensity double poling (DP) on physiological and biomechanical responses during subsequent diagonal stride (DIA). METHODS Eight well-trained male cross-country skiers (age 22 ± 3 yr; VO2max 69 ± 3 ml · kg(-1) · min(-1)) roller-skied on a treadmill sequentially for 3 min at 90% DIA VO2max (DIA1), 3 min at 90% DP VO2peak and 3 min at 90% DIA VO2max (DIA2). Cardio-respiratory responses were monitored continuously and gases and metabolites in blood from the a. femoralis, v. femoralis and v. subclavia determined. Pole and plantar forces and EMG from 6 lower- and upper-body muscles were measured. RESULTS VO2 decreased from DIA1 to DP and increased again to DIA2 (both P < 0.05), with no difference between the DIA sessions. Blood lactate rose from DIA1 to DP to DIA2. O2 extraction was attenuated during DP (P < 0.05), but was the same during DIA1 and DIA2. EMGRMS for arm muscles during poling phase, as well as peak pole force and cycle rate were higher, while leg muscle activity was lower during DP than both sessions of DIA (all P < 0.05). The ratio of upper-/whole-body EMGRMS correlated negatively with O2 extraction in the arms during both sessions of DIA (P < 0.05). CONCLUSIONS In well-trained skiers skiing at high-intensity DP prior to DIA did not influence VO2, muscle activation or forces in the latter. At race intensity DP does not influence the distribution of work between upper- and lower-body during a subsequent bout of DIA. O2 extraction is coupled to technical skills during skiing.
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Affiliation(s)
- Glenn Björklund
- Department of Health Sciences, Swedish Winter Sports Research Centre, Mid-Sweden University, 831 25 Östersund, Sweden
| | - Hans-Christer Holmberg
- Department of Health Sciences, Swedish Winter Sports Research Centre, Mid-Sweden University, 831 25 Östersund, Sweden ; Swedish Olympic Committee, Stockholm, Sweden
| | - Thomas Stöggl
- Department of Health Sciences, Swedish Winter Sports Research Centre, Mid-Sweden University, 831 25 Östersund, Sweden ; Department of Sport Science and Kinesiology, University of Salzburg, Salzburg, Austria
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Stöggl T, Björklund G, Holmberg HC. Biomechanical determinants of oxygen extraction during cross-country skiing. Scand J Med Sci Sports 2012; 23:e9-20. [PMID: 23039095 DOI: 10.1111/sms.12004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2012] [Indexed: 11/29/2022]
Abstract
To determine the relationship of muscle activation, force production, and cycle characteristics to O(2) extraction during high- and lower-intensity double poling (DP), nine well-trained male cross-country skiers performed DP on a treadmill for 3 min at 90% VO(2peak) followed by 6 min at 70%. During the final minute at each workload, arterial, femoral, and subclavian venous blood were collected for determination of partial pressure of O(2), partial pressure of CO(2), pH, and lactate. Electromyography (EMG) was recorded from six upper and lower body muscles, leg and pole forces were measured, and cardiorespiratory variables were monitored continuously. O(2) extraction was associated with time point of peak pole force (PF(peak)), duration of recovery, EMG activity, and lower body use. Arm O(2) extraction was lower than in the legs at both intensities (P < 0.001) and was reduced to a lesser extent upon decreasing the workload (P < 0.05). Arm root-mean-square EMG was higher during the poling phase and entire cycle compared with the legs (P < 0.001). Blood lactate was higher in the subclavian than in femoral vein and artery (P < 0.001) and independent of intensity. O(2) extraction was correlated to low muscle activation, later PF(peak) , prolonged poling time, and extensive dynamic lower body use. Cycle rate and recovery time were associated with O(2) extraction during high-intensity exercise only.
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Affiliation(s)
- T Stöggl
- Department of Sport Science and Kinesiology, University of Salzburg, Salzburg, Austria.
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