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Usher A, Babraj J. Use of NIRS to explore skeletal muscle oxygenation during different training sessions in professional boxing. Eur J Appl Physiol 2024; 124:595-606. [PMID: 37656280 PMCID: PMC10858063 DOI: 10.1007/s00421-023-05305-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/25/2023] [Indexed: 09/02/2023]
Abstract
PURPOSE The physiological examination of boxing has been limited to systemic response in amateur athletes. The demands of professional boxing have been overlooked, despite the different competition format. We sought to determine the physiological demands placed on skeletal muscle in professional boxing. METHODS Ten male professional boxers (age 26 ± 5 years, height 177 ± 4 cm, weight 71 ± 6 kg) were recruited for this observational study. On different days, the athletes completed 6 × 3 min rounds of pad, bag or spar-based training with 1 min recovery between each round. Prior to each session, participants put on a heart rate monitor and near-infrared spectroscopy attached to the belly of the rectus femoris muscle to record heart rate and muscle oxygenation. RESULTS There were significantly less punches thrown in sparring compared to other training modalities (p < 0.001). Skeletal muscle oxygenation across training modalities consisted of a delay, fast desaturation and steady state. Across rounds there was a significant increase in time delay for desaturation (p = 0.016), rate of fast desaturation (p < 0.001) and duration of fast desaturation (p = 0.019). There was a significant difference in sparring for the heart rate where skeletal muscle oxygenation changes occurred compared to pads or bag sessions (p < 0.001). CONCLUSION The findings highlight differences in the skeletal muscle response to the different training modalities. Practitioners need to be aware of the muscular demands of each session to allow optimal adaptation across a training camp. Training needs to allow the skeletal muscle to achieve a new oxygenation steady state rapidly to promote efficient performance across rounds.
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Affiliation(s)
- Andrew Usher
- Department of Sport and Exercise Science, Abertay University, Bell St, Dundee, DD1 1HG, Scotland.
| | - John Babraj
- Department of Sport and Exercise Science, Abertay University, Bell St, Dundee, DD1 1HG, Scotland
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Hall AJ, Aspe RR, Craig TP, Kavaliauskas M, Babraj J, Swinton PA. The Effects of Sprint Interval Training on Physical Performance: A Systematic Review and Meta-Analysis. J Strength Cond Res 2023; 37:457-481. [PMID: 36165995 DOI: 10.1519/jsc.0000000000004257] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
ABSTRACT Hall, AJ, Aspe, RR, Craig, TP, Kavaliauskas, M, Babraj, J, and Swinton, PA. The effects of sprint interval training on physical performance: a systematic review and meta-analysis. J Strength Cond Res 37(2): 457-481, 2023-The present study aimed to synthesize findings from published research and through meta-analysis quantify the effect of sprint interval training (SIT) and potential moderators on physical performance outcomes (categorized as aerobic, anaerobic, mixed aerobic-anaerobic, or muscular force) with healthy adults, in addition to assessing the methodological quality of included studies and the existence of small study effects. Fifty-five studies were included (50% moderate methodological quality, 42% low methodological quality), with 58% comprising an intervention duration of ≤4 weeks and an array of different training protocols. Bayesian's meta-analysis of standardized mean differences (SMD) identified a medium effect of improved physical performance with SIT (ES 0.5 = 0.52; 95% credible intervals [CrI]: 0.42-0.62). Moderator analyses identified overlap between outcome types with the largest effects estimated for anaerobic outcomes (ES 0.5 = 0.61; 95% CrI: 0.48-0.75). Moderator effects were identified for intervention duration, sprint length, and number of sprints performed per session, with larger effects obtained for greater values of each moderator. A substantive number of very large effect sizes (41 SMDs > 2) were identified with additional evidence of extensive small study effects. This meta-analysis demonstrates that short-term SIT interventions are effective for developing moderate improvements in physical performance outcomes. However, extensive small study effects, likely influenced by researchers analyzing many outcomes, suggest potential overestimation of reported effects. Future research should analyze fewer a priori selected outcomes and investigate models to progress SIT interventions for longer-term performance improvements.
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Affiliation(s)
- Andy J Hall
- Department of Sport and Exercise, School of Health Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - Rodrigo R Aspe
- Department of Sport and Exercise, School of Health Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - Thomas P Craig
- Department of Sport and Exercise, School of Health Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - Mykolas Kavaliauskas
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, United Kingdom ; and
| | - John Babraj
- Division of Sport and Exercise Science, Abertay University, Dundee, United Kingdom
| | - Paul A Swinton
- Department of Sport and Exercise, School of Health Sciences, Robert Gordon University, Aberdeen, United Kingdom
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Morgans R, Bezuglov E, Orme P, Burns K, Rhodes D, Babraj J, Di Michele R, Oliveira RFS. The Physical Demands of Match-Play in Academy and Senior Soccer Players from the Scottish Premiership. Sports (Basel) 2022; 10:sports10100150. [PMID: 36287763 PMCID: PMC9608936 DOI: 10.3390/sports10100150] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 11/20/2022] Open
Abstract
The present study aimed to assess the physical match performance among senior and youth soccer players from an elite Scottish Premiership club during the 2021/2022 season. Twenty-two first team (25.9 ± 4.5 years, 78.3 ± 8.2 kg, 1.82 ± 0.07 cm) and 16 youth players (16.8 ± 0.9 years, 70.1 ± 6.8 kg, 177 ± 5.8 cm) were examined. A selection of physical match performance variables were measured using a global positioning system. Linear mixed-effect regressions revealed for all examined variables no significant differences between first team and U-18 players and no significant differences between playing level by position interaction. Across both teams, Centre Backs compared to Wing Backs, showed a 295 m (p < 0.01) lower high-intensity distance, and performed on average 36 fewer very-high intensity decelerations (p = 0.03). Comparing to Wide Midfielders, Centre Backs showed lower total (1297 m, p = 0.01), high-intensity (350 m, p = 0.01), and sprint (167 m, p < 0.01) distances. Sprint distance was also lower in Centre Backs vs. Strikers (118 m, p = 0.03), and in Central Midfielders vs. both Strikers (104 m, p = 0.03) and Wide Midfielders (154 m, p = 0.01). The present findings highlight the physical match performance of elite Scottish players and provide useful information within the context of understanding how methods of physical development of youth soccer are implemented in different countries.
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Affiliation(s)
- Ryland Morgans
- Department of Sports Medicine and Medical Rehabilitation, Sechenov State Medical University Moscow, 119991 Moscow, Russia
- Correspondence:
| | - Eduard Bezuglov
- Department of Sports Medicine and Medical Rehabilitation, Sechenov State Medical University Moscow, 119991 Moscow, Russia
- High Performance Sports Laboratory, Moscow Witte University, 115432 Moscow, Russia
| | - Patrick Orme
- Sport Science and Medical Department, Bristol City FC, Bristol BS3 2EJ, UK
| | - Kyler Burns
- Sport Science and Medical Department, Dundee United FC, Dundee DD3 7JW, UK
| | - Dave Rhodes
- Football Performance Hub, School of Sport and Health Sciences, University of Central Lancashire, Preston PR1 2HE, UK
| | - John Babraj
- Division of Sport and Exercise Sciences, School of Applied Sciences, Abertay University, Dundee DD1 1HG, UK
| | - Rocco Di Michele
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
| | - Rafael Franco Soares Oliveira
- Sports Science School of Rio Maior-Polytechnic Institute of Santarém, 2040-413 Rio Maior, Portugal
- Life Quality Research Centre, 2040-413 Rio Maior, Portugal
- Research Centre in Sport Sciences, Health Sciences and Human Development, 5001-801 Vila Real, Portugal
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Marley A, Grant M, Babraj J. Vitamin D3 supplementation combined with sprint interval training improves aerobic and anaerobic exercise performance over sprint interval training alone in recreational combat sport athletes. Sci Sports 2022. [DOI: 10.1016/j.scispo.2021.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Thom G, Kavaliauskas M, Babraj J. Changes in lactate kinetics underpin soccer performance adaptations to cycling-based sprint interval training. Eur J Sport Sci 2020; 20:486-494. [PMID: 31232639 DOI: 10.1080/17461391.2019.1635650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In adolescent soccer, 23% of the distance covers happens at speeds above onset of blood lactate accumulation which suggests that lactate kinetics may be important for soccer performance. We sought to determine the effectiveness of sprint interval training (SIT) on changing performance and lactate kinetics in adolescent soccer players. Thirteen elite soccer academy players (age 15 ± 0.5y) underwent baseline testing (0-10 m and 10-20 m sprint performance, Wingate anaerobic Test (WaNT) with blood lactate measurements and incremental VO2 peak test) before being allocated to control or SIT group. The control group maintained training whilst the HIT group carried out twice-weekly all-out effort cycle sprints consisting of 6 × 10 s sprint with 80 s recovery. There were significant time x group interactions for 10-20 m sprint time (Control pre: 1.32 ± 0.07 s post: 1.35 ± 0.08 s; SIT pre: 1.29 ± 0.04 s post: 1.25 ± 0.04 s; p = 0.01), Peak Power (Control pre: 13.1 ± 1.3 W.kg-1 post: 13.2 ± 1.47 W.kg-1; SIT pre: 12.4 ± 1.3 W.kg-1 post: 15.3 ± 0.7 W.kg-1; p = 0.01) and time to exhaustion (Control pre: 596 ± 62 s post: 562 ± 85 s; SIT pre: 655 ± 54 s post: 688 ± 55 s; p = 0.001). The changes in performance were significantly correlated to changes in lactate kinetics (power: r = 0.55; 10-20 m speed: r = -0.54; time to exhaustion: r = 0.55). Therefore, cycle based SIT is an effective training paradigm for elite adolescent soccer players and the improvements in performance are associated with changes in lactate kinetics.
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Affiliation(s)
- Graham Thom
- Division of Sport and Exercise Science, Abertay University, Dundee, Scotland
| | - Mykolas Kavaliauskas
- School of Applied Sciences, Sport, Exercise and Health Sciences, Edinburgh Napier University, Edinburgh, Scotland
| | - John Babraj
- Division of Sport and Exercise Science, Abertay University, Dundee, Scotland
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Affiliation(s)
- Andrew Marley
- School of Applied Sciences, Division of Sport and Exercise Science, Abertay University, Dundee, UK
| | - Marie Clare Grant
- School of Applied Sciences, Division of Sport and Exercise Science, Abertay University, Dundee, UK
| | - John Babraj
- School of Applied Sciences, Division of Sport and Exercise Science, Abertay University, Dundee, UK
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Abstract
Yamagishi, T and Babraj, J. Active recovery induces greater endurance adaptations when performing sprint interval training. J Strength Cond Res 33(4): 922–930, 2019—This study sought to determine effects of recovery intensity on endurance adaptations during sprint interval training (SIT). Fourteen healthy young adults (male: 9 and female: 5) were allocated to 1 of 2 training groups: active recovery group (ARG, male: 4 and female: 3) or passive recovery group (PRG, male: 5 and female: 2). After having completed a 2-week control period, both groups performed 6 sessions of 4- to 6 30-second sprints interspersed with 4-minute recovery over 2 weeks. However, only ARG cycled at 40% V̇o2peak during the 4-minute recovery periods, while PRG rested on the bike or cycled unloaded. After the 2-week training intervention, both groups improved 10-km time-trial performance to a similar extent (ARG: 8.6%, d = 1.60, p = 0.006; PRG: 6.7%, d = 0.96, p = 0.048) without gains in V̇o2peak. However, critical power was increased by ARG only (7.9%, d = 1.75, p = 0.015) with a tendency of increased maximal incremental power output (5.3%, d = 0.88, p = 0.063). During the training, active recovery maintained V̇o2 and heart rate at a higher level compared with passive recovery (V̇o2: p = 0.005, HR: p = 0.018), suggesting greater cardiorespiratory demands with the active recovery. This study demonstrated that greater endurance performance adaptations are induced with active recovery when performing SIT over a short time frame. The findings of the current study indicate that, with active recovery, individuals can gain greater training benefits without increasing total training commitment time. Further studies are required to determine whether differences are seen with recovery intensity over a longer period.
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Affiliation(s)
- Takaki Yamagishi
- Division of Sport and Exercise Sciences, Abertay University, Dundee, Scotland.,Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
| | - John Babraj
- Division of Sport and Exercise Sciences, Abertay University, Dundee, Scotland
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Yamagishi T, Babraj J. Effects of reduced-volume of sprint interval training and the time course of physiological and performance adaptations. Scand J Med Sci Sports 2017; 27:1662-1672. [PMID: 28124388 DOI: 10.1111/sms.12831] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2016] [Indexed: 12/31/2022]
Abstract
This study sought to determine the time course of training adaptations to two different sprint interval training programmes with the same sprint: rest ratio (1:8) but different sprint duration. Nine participants (M: 7; F: 2) were assigned to 15-second training group (15TG) consisting of 4-6 × 15-second sprints interspersed with 2-minute recovery, whereas eight participants (M: 5; F: 3) were assigned to 30-second training group (30TG) consisting of 4-6 × 30 second sprints interspersed with 4-minute recovery. Both groups performed their respective training twice per week over 9 weeks and changes in peak oxygen uptake (V˙O2peak) and time to exhaustion (TTE) were assessed every 3 weeks. Additional eight healthy active adults (M: 6; F: 2) completed the performance assessments 9 weeks apart without performing training (control group, CON). Following 9 weeks of training, both groups improved V˙O2peak (15TG: 12.1%; 30TG: 12.8%, P<.05) and TTE (15TG: 16.2%; 30TG: 12.8%, P<.01) to a similar extent. However, while both groups showed the greatest gains in V˙O2peak at 3 weeks (15TG: 16.6%; 30TG: 17.0%, P<.001), those in TTE were greatest at 9 weeks. CON did not change any of performance variables following 9 weeks. This study demonstrated that while the changes in cardiorespiratory function plateau within several weeks with sprint interval training, endurance capacity (TTE) is more sensitive to such training over a longer time frame in moderately-trained individuals. Furthermore, a 50% reduction in sprint duration does not diminish overall training adaptations over 9 weeks.
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Affiliation(s)
- T Yamagishi
- Division of Sport and Exercise Sciences, Abertay University, Dundee, Scotland.,Faculty of Sport Sciences, Waseda University, Saitama, Japan
| | - J Babraj
- Division of Sport and Exercise Sciences, Abertay University, Dundee, Scotland
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Kavaliauskas M, Kilvington R, Babraj J. Effects of in-season uphill sprinting on physical characteristics in semi-professional soccer players. J Sports Med Phys Fitness 2017; 57:165-170. [DOI: 10.23736/s0022-4707.16.06066-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Yamagishi T, Babraj J. Influence of recovery intensity on oxygen demand and repeated sprint performance. J Sports Med Phys Fitness 2016; 56:1103-1112. [PMID: 26364688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
BACKGROUND This study aimed to determine effects of recovery intensity (passive, 20%, 30% and 40% V̇O2peak) on oxygen uptake kinetics, performance and blood lactate accumulation during repeated sprints. METHODS Seven moderately-trained male participants (V̇O2peak: 48.1±5.1 mL/kg/min) performed four 30-second repeated Wingate tests on four separate occasions. RESULTS Recovery of V̇O2 between sprints was prolonged with recovery intensity (time required to reach 50% V̇O2peak: passive: 50±9 s; 20%: 81±17 s; 30%: 130±43 s; 40%: 188±62 s, P<0.001), while V̇O2-to-sprint work ratio was mainly increased by the higher intensities (passive: 138±17 mL/min/kJ; 20%: 149±14 mL/min/kJ; 30%: 159±15 mL/min/kJ; 40%: 158±17 mL/min/kJ, P=0.001). The decline in peak power tended to be greater in the higher intensity conditions during sprint 2 (passive: 7.4±5.4%; 20%: 5.8±7.9%; 30%: 12.7±7.4%; 40%: 12.7±5.5%, P=0.052), whereas average power was less decreased with recovery intensity during sprint 4 (passive: 22.4±8.9%; 20%: 19.9±6.1%; 30%: 18.4±7.3%; 40%: 16.6±6.2%, P=0.036). Blood lactate was not different with recovery intensity (P=0.251). CONCLUSIONS The present study demonstrated that while the higher recovery intensities induce prolonged oxygen recovery and impaired peak power restoration during the initial sprints, those intensities provide a greater aerobic contribution to sprint performance, resulting in better power maintenance during the latter sprints.
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Affiliation(s)
- Takaki Yamagishi
- Division of Sport and Exercise Sciences, Abertay University, Dundee, Scotland, UK -
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Abstract
The work-to-rest ratio during cycling-based high-intensity interval training (HIT) could be important in regulating physiological and performance adaptations. We sought to determine the effectiveness of cycling-based HIT with different work-to-rest ratios for long-distance running. Thirty-two long-distance runners (age: 39 ± 8 years; sex: 14 men, 18 women; average weekly running training volume: 25 miles) underwent baseline testing (3-km time-trial, V[Combining Dot Above]O2peak and time to exhaustion, and Wingate test) before a 2-week matched-work cycling HIT of 6 × 10-second sprints with different rest periods (30 seconds [R30], 80 seconds [R80], 120 seconds [R120], or control). Three-kilometer time trial was significantly improved in the R30 group only (3.1 ± 4.0%, p = 0.04), whereas time to exhaustion was significantly increased in the 2 groups with a lower work-to-rest ratio (R30 group 6.4 ± 6.3%, p = 0.003 vs. R80 group 4.4 ± 2.7%, p = 0.03 vs. R120 group 1.9 ± 5.0%, p = 0.2). However, improvements in average power production were significantly greater with a higher work-to-rest ratio (R30 group 0.3 ± 4.1%, p = 0.8 vs. R80 group 4.6 ± 4.2%, p = 0.03 vs. R120 group 5.3 ± 5.9%, p = 0.02), whereas peak power significantly increased only in the R80 group (8.5 ± 8.2%, p = 0.04) but not in the R30 group (4.3 ± 6.1%, p = 0.3) or in the R120 group (7.1 ± 7.9%, p = 0.09). Therefore, cycling-based HIT is an effective way to improve running performance, and the type and magnitude of adaptation is dependent on the work-to-rest ratio.
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Affiliation(s)
- Mykolas Kavaliauskas
- 1Division of Sport and Exercise Sciences, Abertay University, Dundee, United Kingdom; and 2School of Sport and Exercise, University of Gloucestershire, Gloucester, United Kingdom
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Hawkey A, Griffiths K, Babraj J, Cobley JN. Whole-Body Vibration Training and Its Application to Age-Related Performance Decrements. J Strength Cond Res 2016; 30:555-60. [DOI: 10.1519/jsc.0000000000001111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lorimer R, Babraj J. The Potential Influence of Perception of Achievement on Performance in Volitional Time-To-Exhaustion Cycle Ergometer Trials. J Strength Cond Res 2013; 27:1546-8. [DOI: 10.1519/jsc.0b013e318274f1e3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Jakeman J, Adamson S, Babraj J. Extremely short duration high-intensity training substantially improves endurance performance in triathletes. Appl Physiol Nutr Metab 2012; 37:976-81. [PMID: 22857018 DOI: 10.1139/h2012-083] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High-intensity training (HIT) involving 30-s sprints is an effective training regimen to improve aerobic performance. We tested whether 6-s HITs can improve aerobic performance in triathletes. Six subelite triathletes (age, 40 ± 9 years; weight, 86 ± 11 kg; body mass index, 26 ± 3 kg·m⁻²) took part in cycle HIT and 6 endurance-trained subelite athletes (age, 36 ± 9 years; weight, 82 ± 11 kg; BMI, 26 ± 3 kg·m⁻²) maintained their normal training routine. Before and after 2 weeks of HIT, involving 10 × 6-s sprints or normal activity, participants performed a self-paced 10-km time trial and a time to exhaustion test on a cycle ergometer. Finger prick blood samples were taken throughout the time to exhaustion test to determine blood lactate concentration. Two weeks of HIT resulted in a 10% decrease in self-paced 10-km time trial (p = 0.03) but no significant change in time to exhaustion. The time taken to reach onset of blood lactate accumulation (OBLA, defined as the point where blood lactate reaches 4 mmol·L⁻¹) was significantly increased following 2 weeks of HIT (p = 0.003). The change in time trial performance was correlated to the change in time taken to reach OBLA (R² = 0.63; p = 0.001). We concluded that a very short duration HIT is a very effective training regimen to improve aerobic performance in subelite triathletes and this is associated with a delay in blood lactate build-up.
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Affiliation(s)
- John Jakeman
- Department of Sport and Health Sciences, Oxford Brookes University, Oxford OX3 0BP, England
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Gakamsky DM, Dhillon B, Babraj J, Shelton M, Smith SD. Exploring the possibility of early cataract diagnostics based on tryptophan fluorescence. J R Soc Interface 2011; 8:1616-21. [PMID: 21508010 DOI: 10.1098/rsif.2010.0608] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A novel route for early cataract diagnostics is investigated based on the excitation of tryptophan fluorescence (TF) at the red edge of its absorption band at 317 nm. This allows penetration through the cornea and aqueous humour to provide excitation of the ocular lens. The steepness of the red edge gives the potential of depth control of the lens excitation. Such wavelength selection targets the population of tryptophan residues, side chains of which are exposed to the polar aqueous environment. The TF emissions around 350 nm of a series of UV-irradiated as well as control lenses were observed. TF spectra of the UV cases were red-shifted and the intensity decreased with the radiation dose. In contrast, intensity of non-tryptophan emission with maximum at 435 nm exhibited an increase suggesting photochemical conversion of the tryptophan population to 435 nm emitting molecules. We demonstrate that the ratio of intensities at 435 nm to that around 350 nm can be used as a measure of early structural changes caused by UV irradiation in the lens by comparison with images from a conventional slit-lamp, which can only detect defects of optical wavelength size. Such diagnostics at a molecular level could aid research on cataract risk investigation and possible pharmacological research as well as assisting surgical lens replacement decisions.
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Affiliation(s)
- Dmitry M Gakamsky
- Royal Society Industry Fellow at Edinburgh Instruments, Livingston, EH54 7DQ, UK
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Cuthbertson DJ, Babraj J, Smith K, Wilkes E, Fedele MJ, Esser K, Rennie M. Anabolic signaling and protein synthesis in human skeletal muscle after dynamic shortening or lengthening exercise. Am J Physiol Endocrinol Metab 2006; 290:E731-8. [PMID: 16263770 DOI: 10.1152/ajpendo.00415.2005] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We hypothesized a differential activation of the anabolic signaling proteins protein kinase B (PKB) and p70 S6 kinase (p70(S6K)) and subsequent differential stimulation of human muscle protein synthesis (MPS) after dynamic shortening or lengthening exercise. Eight healthy men [25 +/- 5 yr, BMI 26 +/- 3 kg/m(-2) (means +/- SD)] were studied before and after 12 min of repeated stepping up to knee height, and down again, while carrying 25% of their body weight, i.e., shortening exercise with the "up" leg and lengthening exercise with contralateral "down" leg. Quadriceps biopsies were taken before and 3, 6, and 24 h after exercise. After exercise, over 2 h before the biopsies, the subjects ingested 500 ml of water containing 45 g of essential amino acids and 135 g of sucrose. Rates of muscle protein synthesis were determined via incorporation over time of [1-(13)C]leucine (<or=6 h after exercise) or [1-(13)C]valine (21-24 h after exercise) and phosphorylation of signaling proteins by Western analysis. PKB and p70(S6K) phosphorylation increased approximately 3-fold after 3 h and remained elevated at 6 and 24 h. After exercise, rates of myofibrillar and sarcoplasmic protein synthesis were unchanged over the period including exercise and 3 h of recovery but had increased significantly at 6 (approximately 3.0- and 2.4-fold, respectively) and 24 h (approximately 3.2- and 2.0-fold, respectively), independently of the mode of exercise. Short-term dynamic exercise in either shortening or lengthening mode increases MPS at least as much as resistance exercise and is associated with long-term activation of PKB and p70(S6K).
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Esmarck B, Diederichsen L, Hall G, Babraj J, Smith K, Rennie MJ, Kjaer M. Similar 24h anabolic response to intact and hydrolysed whey protein ingested postexercise in elderly subjects. FASEB J 2006. [DOI: 10.1096/fasebj.20.5.a1469-c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Birgitte Esmarck
- Institute of Sports MedicineBispebjerg University HospitalBispebjerg Bakke 23Copenhagen2400Denmark
- Copenhagen Muscle Research CenterRigshospitaletDept. 7652, Tagensvej 20Copenhagen N2200Denmark
| | - Louise Diederichsen
- Institute of Sports MedicineBispebjerg University HospitalBispebjerg Bakke 23Copenhagen2400Denmark
| | - Gerrit Hall
- Copenhagen Muscle Research CenterRigshospitaletDept. 7652, Tagensvej 20Copenhagen N2200Denmark
| | - John Babraj
- Division of Molecular PhysiologyUniversity of DundeeDundeeUnited Kingdom
| | - Kenneth Smith
- School of Biomedical SciencesUniversity of NottinghamDerbyNottinghamUnited Kingdom
| | - Michael J Rennie
- School of Biomedical SciencesUniversity of NottinghamDerbyNottinghamUnited Kingdom
| | - Michael Kjaer
- Institute of Sports MedicineBispebjerg University HospitalBispebjerg Bakke 23Copenhagen2400Denmark
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Babraj J, Cuthbertson D, Smith K, Rickhus P, Rennie M. Ageing and human bone collagen synthesis. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- John Babraj
- Molecular PhysiologyUniversity of DundeeMSI/WTB complex, Dow streetDundeeDD1 4HNUnited Kingdom
| | - Daniel Cuthbertson
- Molecular PhysiologyUniversity of DundeeMSI/WTB complex, Dow streetDundeeDD1 4HNUnited Kingdom
| | - Kenneth Smith
- Biomedical SciencesUniversity of NottinghamUttoxeter RoadDerbyDE22 3DTUnited Kingdom
| | - Peter Rickhus
- Dept of Orthopeadic SurgeryNinewells Hospital and Medical SchoolNinewells AvenueDundeeDD2 9STUnited Kingdom
| | - Michael Rennie
- Biomedical SciencesUniversity of NottinghamUttoxeter RoadDerbyDE22 3DTUnited Kingdom
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Atherton PJ, Babraj J, Smith K, Singh J, Rennie MJ, Wackerhage H. Selective activation of AMPK-PGC-1alpha or PKB-TSC2-mTOR signaling can explain specific adaptive responses to endurance or resistance training-like electrical muscle stimulation. FASEB J 2005; 19:786-8. [PMID: 15716393 DOI: 10.1096/fj.04-2179fje] [Citation(s) in RCA: 333] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Endurance training induces a partial fast-to-slow muscle phenotype transformation and mitochondrial biogenesis but no growth. In contrast, resistance training mainly stimulates muscle protein synthesis resulting in hypertrophy. The aim of this study was to identify signaling events that may mediate the specific adaptations to these types of exercise. Isolated rat muscles were electrically stimulated with either high frequency (HFS; 6x10 repetitions of 3 s-bursts at 100 Hz to mimic resistance training) or low frequency (LFS; 3 h at 10 Hz to mimic endurance training). HFS significantly increased myofibrillar and sarcoplasmic protein synthesis 3 h after stimulation 5.3- and 2.7-fold, respectively. LFS had no significant effect on protein synthesis 3 h after stimulation but increased UCP3 mRNA 11.7-fold, whereas HFS had no significant effect on UCP3 mRNA. Only LFS increased AMPK phosphorylation significantly at Thr172 by approximately 2-fold and increased PGC-1alpha protein to 1.3 times of control. LFS had no effect on PKB phosphorylation but reduced TSC2 phosphorylation at Thr1462 and deactivated translational regulators. In contrast, HFS acutely increased phosphorylation of PKB at Ser473 5.3-fold and the phosphorylation of TSC2, mTOR, GSK-3beta at PKB-sensitive sites. HFS also caused a prolonged activation of the translational regulators p70 S6k, 4E-BP1, eIF-2B, and eEF2. These data suggest that a specific signaling response to LFS is a specific activation of the AMPK-PGC-1alpha signaling pathway which may explain some endurance training adaptations. HFS selectively activates the PKB-TSC2-mTOR cascade causing a prolonged activation of translational regulators, which is consistent with increased protein synthesis and muscle growth. We term this behavior the "AMPK-PKB switch." We hypothesize that the AMPK-PKB switch is a mechanism that partially mediates specific adaptations to endurance and resistance training, respectively.
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Affiliation(s)
- P J Atherton
- School of Life Sciences, University of Dundee, UK
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Cuthbertson D, Smith K, Babraj J, Leese G, Waddell T, Atherton P, Wackerhage H, Taylor PM, Rennie MJ. Anabolic signaling deficits underlie amino acid resistance of wasting, aging muscle. FASEB J 2004; 19:422-4. [PMID: 15596483 DOI: 10.1096/fj.04-2640fje] [Citation(s) in RCA: 814] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The nature of the deficit underlying age-related muscle wasting remains controversial. To test whether it could be due to a poor anabolic response to dietary amino acids, we measured the rates of myofibrillar and sarcoplasmic muscle protein synthesis (MPS) in 44 healthy young and old men, of similar body build, after ingesting different amounts of essential amino acids (EAA). Basal rates of MPS were indistinguishable, but the elderly showed less anabolic sensitivity and responsiveness of MPS to EAA, possibly due to decreased intramuscular expression, and activation (phosphorylation) after EAA, of amino acid sensing/signaling proteins (mammalian target of rapamycin, mTOR; p70 S6 kinase, or p70(S6k); eukaryotic initiation factor [eIF]4BP-1; and eIF2B). The effects were independent of insulin signaling since plasma insulin was clamped at basal values. Associated with the anabolic deficits were marked increases in NFkappaB, the inflammation-associated transcription factor. These results demonstrate first, EAA stimulate MPS independently of increased insulin availability; second, in the elderly, a deficit in MPS in the basal state is unlikely; and third, the decreased sensitivity and responsiveness of MPS to EAA, associated with decrements in the expression and activation of components of anabolic signaling pathways, are probably major contributors to the failure of muscle maintenance in the elderly. Countermeasures to maximize muscle maintenance should target these deficits.
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Affiliation(s)
- Daniel Cuthbertson
- Division of Molecular Physiology, School of Life Sciences, University of Dundee, Dundee, Scotland
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Babraj J, Cuthbertson DJ, Rickhuss P, Meier-Augenstein W, Smith K, Bohé J, Wolfe RR, Gibson JNA, Adams C, Rennie MJ. Sequential extracts of human bone show differing collagen synthetic rates. Biochem Soc Trans 2002; 30:61-65. [PMID: 12023825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Type I collagen is the major bone protein. Little is known quantitatively about human bone collagen synthesis in vivo, despite its importance for the understanding of bone formation and turnover. Our aim was to develop a method that could be used for the physiological and pathophysiological investigation of human bone collagen synthesis. We have carried out preliminary studies in patients undergoing hip replacement and in pigs to validate the use of the flooding dose method using (13)C- or (15)N-labelled proline and we have now refined our techniques to allow them to be used in a normal clinical or physiological setting. The results show that the application of a flooding dose causes bone free-proline labelling to equilibrate with that of blood in pigs and human beings, so that only 150 mg of bone will provide enough sample to prepare and measure the labelling of three fractions of bone collagen (dissolved in NaCl, acetic acid and pepsin/acetic acid) which have the same relative labelling (1.0:0.43:0.1) as measured by GC-combustion-isotope ratio MS. The rates of incorporation were substantially faster than in skeletal muscle samples taken at the same time. The results suggest that different fractions of human bone collagen turnover at markedly higher rates than had been previously considered. This approach should allow us to discover how growth and development, food, activity and drugs affect bone collagen turnover and to measure the effects on it of ageing and bone disease.
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Affiliation(s)
- J Babraj
- Division of Molecular Physiology, School of Life Sciences, University of Dundee, Dundee DD1 4HN, Scotland, U.K.
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