Influence of workload and recovery on injuries in elite male volleyball players
- Timoteo, Thiago, Debien, Paula, Miloski, Bernardo, Werneck, Francisco, Gabbett, Tim, Bara Filho, Mauricio
- Authors: Timoteo, Thiago , Debien, Paula , Miloski, Bernardo , Werneck, Francisco , Gabbett, Tim , Bara Filho, Mauricio
- Date: 2021
- Type: Text , Journal article
- Relation: Journal of strength and conditioning research Vol. 35, no. 3 (2021), p. 791-796
- Full Text: false
- Reviewed:
- Description: ABSTRACT: Timoteo, TF, Debien, PB, Miloski, B, Werneck, FZ, Gabbett, T, and Filho, MGb. Influence of workload and recovery on injuries in elite male volleyball players. J Strength Cond Res 35(3): 791-796, 2021-The aim of this study was to investigate the influence of workload and recovery on injury rates in elite male volleyball players. Data were collected from 14 male professional volleyball players over a 27-week season. Workloads were monitored daily using the session rating of perceived exertion, and recovery status was appraised using the Total Quality Recovery (TQR) scale. The players were exposed to 4,573.31 hours (h) of training and games with an overall injury incidence of 13.99 per 1,000 hours. Overuse accounted for 83% (11.58 injuries/1,000 hours) and trauma accounted for 17% (2.40 injuries per 1,000 hours) of all injuries. There was a higher incidence of injuries (p = 0.003), higher weekly workload (p = 0.008), and acute:chronic workload ratio (ACWR) (p < 0.001) in the pre-season compared with the competitive period. Healthy players had lower ACWR (p = 0.002) compared with the injured players. The TQR was higher for the healthy group compared with the injured group (p < 0.001). The greater odds of injury was related to higher ACWR (risk factor) (p = 0.014) and lower TQR values (p = 0.004) (protection factor). Athlete's workloads and the state of recovery may be related to injuries in volleyball. The results presented in this study emphasize the importance of controlling these variables in professional volleyball teams to prevent injuries. Copyright © 2018 National Strength and Conditioning Association.
Self-reported wellness profiles of professional australian football players during the competition phase of the season
- Gallo, Tania, Cormack, Stuart, Gabbett, Tim, Lorenzen, Christian
- Authors: Gallo, Tania , Cormack, Stuart , Gabbett, Tim , Lorenzen, Christian
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 31, no. 2 (2017), p. 495-502
- Full Text:
- Reviewed:
- Description: With the prevalence of customized self-report measures in high-performance sport, and the incomplete understanding of athletes' perceived wellness in response to matches and training load, the objective of this study was to explore weekly wellness profiles within the context of the competitive season of professional Australian football. Internal match load, measured through the session-rating of perceived exertion method, match-to-match microcycle, stage of the season, and training load were included in multivariate linear models to determine their effect on weekly wellness profile (n = 1,835). There was a lower weekly training load on a 6-day microcycle compared with a 7-day and 8-day microcycle. Match load had no significant impact on weekly wellness profile, while there was an interaction between microcycle and days postmatch. There was a likely moderately lower wellness Z-score 1 day postmatch for an 8-day microcycle (mean; 95% confidence interval: -1.79; -2.02 to -1.56) compared with a 6-day (-1.19; -1.30 to -1.08) and 7-day (-1.22; -1.34 to -1.09) cycle (d; 95% confidence interval: -0.82; -1.3 to -0.36, -0.78; -1.3 to -0.28, respectively). The second half of the season saw a possibly small reduction in overall wellness Z-score than the first half of the season (0.22; 0.12-0.32). Finally, training load had no effect on wellness Z-score when controlled for days postmatch, microcycle, and stage of the season. These results provide information on the status of players in response to matches and fixed conditions. Knowing when wellness Z-score returns to baseline relative to the length of the microcycle may lead practitioners to prescribe the heaviest load of the week accordingly. Furthermore, wellness "red flags" should be made relative to the microcycles and stage of the season to determine an athlete's status relative to their typical weekly profile. © 2016 National Strength and Conditioning Association.
- Authors: Gallo, Tania , Cormack, Stuart , Gabbett, Tim , Lorenzen, Christian
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 31, no. 2 (2017), p. 495-502
- Full Text:
- Reviewed:
- Description: With the prevalence of customized self-report measures in high-performance sport, and the incomplete understanding of athletes' perceived wellness in response to matches and training load, the objective of this study was to explore weekly wellness profiles within the context of the competitive season of professional Australian football. Internal match load, measured through the session-rating of perceived exertion method, match-to-match microcycle, stage of the season, and training load were included in multivariate linear models to determine their effect on weekly wellness profile (n = 1,835). There was a lower weekly training load on a 6-day microcycle compared with a 7-day and 8-day microcycle. Match load had no significant impact on weekly wellness profile, while there was an interaction between microcycle and days postmatch. There was a likely moderately lower wellness Z-score 1 day postmatch for an 8-day microcycle (mean; 95% confidence interval: -1.79; -2.02 to -1.56) compared with a 6-day (-1.19; -1.30 to -1.08) and 7-day (-1.22; -1.34 to -1.09) cycle (d; 95% confidence interval: -0.82; -1.3 to -0.36, -0.78; -1.3 to -0.28, respectively). The second half of the season saw a possibly small reduction in overall wellness Z-score than the first half of the season (0.22; 0.12-0.32). Finally, training load had no effect on wellness Z-score when controlled for days postmatch, microcycle, and stage of the season. These results provide information on the status of players in response to matches and fixed conditions. Knowing when wellness Z-score returns to baseline relative to the length of the microcycle may lead practitioners to prescribe the heaviest load of the week accordingly. Furthermore, wellness "red flags" should be made relative to the microcycles and stage of the season to determine an athlete's status relative to their typical weekly profile. © 2016 National Strength and Conditioning Association.
- Oranchuk, Dustin, Drinkwater, Eric, Lindsay, Riki, Helms, Eric, Harbour, Eric, Storey, Adam
- Authors: Oranchuk, Dustin , Drinkwater, Eric , Lindsay, Riki , Helms, Eric , Harbour, Eric , Storey, Adam
- Date: 2019
- Type: Text , Journal article
- Relation: International Journal Sports Physiology and Performance Vol. 14, no. 3 (2019), p. 378-384
- Full Text: false
- Reviewed:
- Description: The power clean and other weightlifting movements are commonly used in the development of muscle power. However, there is a paucity of research examining the use of the hook grip (HG) in weightlifting performance. Therefore, the purpose of this study was to compare 1-repetition maximum (1RM) and kinetic, kinematic, and qualitative variables across a range of loads (75-100%) during power-clean performance with an HG and a closed grip. A total of 11 well-trained men (power-clean 1RM = 113.4 [15.9] kg, 1.34 × body mass) with at least 3 mo of HG experience volunteered to participate. Following a familiarization session, 1RM testing with the HG and closed grip were completed 5-7 d apart in a randomized order. Barbell kinetic and kinematic variables were recorded via a force platform and dual linear position transducer system. All subjects had a greater 1RM with the HG than with the closed grip (P < .001, effect size [ES] = 0.43). Peak velocity (ES = 0.41-0.70), peak power (ES = 0.43-0.61), peak force (ES = 0.50-0.57), and catch height (ES = 0.40-0.96) were significantly greater (P < .05) when using the HG at all or most of the submaximal intensities. In addition, subjects reported significantly greater perceptions of grip security, power, and technical competency at submaximal but not maximal loads. Athletes and coaches who implement weightlifting movements in their physical preparation should adopt the HG where possible. Furthermore, researchers and sport scientists should control and report the grip type used when performing weightlifting-type movements.
A 90 minute soccer match induces eccentric hamstring muscles fatigue
- Kakavas, Georgios, Malliaropoulos, Nikos, Gabbett, Tim, Mitrotasios, Michalis, Van Dyk, Nicol, Bikos, Georgios, Maffulli, Nicola
- Authors: Kakavas, Georgios , Malliaropoulos, Nikos , Gabbett, Tim , Mitrotasios, Michalis , Van Dyk, Nicol , Bikos, Georgios , Maffulli, Nicola
- Date: 2021
- Type: Text , Journal article
- Relation: Muscles, Ligaments and Tendons Journal Vol. 11, no. 2 (2021), p. 318-323
- Full Text:
- Reviewed:
- Description: Background/Purpose of the study. Hamstring injuries are the most prevalent muscle injuries in both amateur and professional soccer (football) players. Eccentric strength deficits and muscle strength imbalances have been associated with an increased risk of muscle injuries. The current study is a non-randomised observational study investigating whether fatigue significantly reduces peak eccentric strength of the hamstring muscle group. Methods. Twenty-two right leg dominant professional football players participated in this study. None were injured or were rehabilitating from an injury at the time of testing. The eccentric strength of the hamstring muscles was determined using the Nordic exercise on a Norbord device prior to a 90 minute soccer match and after its end. Results. There was a significant decrease in eccentric strength at the end of the match (before the match: M = 306.91, SD = 59.26; after the match: Mean = 277.77 ± SD = 60.35 p =.000, Cohen’s d =.50). The imbalance in eccentric hamstring muscle strength between dominant and non-dominant limb before the match remained unchanged after its end. Conclusions. A professional football match significantly impacts on the ability of players to produce high speed eccentric strength in the hamstring muscle groups. Resistance to fatigue and eccentric strength, particularly at high speeds, are considerable factors in conditioning of professional soccer players. Eccentric muscle strength fatigue of the hamstring muscle group after a 90 min soccer match may provide a possible explanation for the greater risk of hamstring injuries under fatigue conditions. © 2021, CIC Edizioni Internazionali s.r.l.. All rights reserved.
- Authors: Kakavas, Georgios , Malliaropoulos, Nikos , Gabbett, Tim , Mitrotasios, Michalis , Van Dyk, Nicol , Bikos, Georgios , Maffulli, Nicola
- Date: 2021
- Type: Text , Journal article
- Relation: Muscles, Ligaments and Tendons Journal Vol. 11, no. 2 (2021), p. 318-323
- Full Text:
- Reviewed:
- Description: Background/Purpose of the study. Hamstring injuries are the most prevalent muscle injuries in both amateur and professional soccer (football) players. Eccentric strength deficits and muscle strength imbalances have been associated with an increased risk of muscle injuries. The current study is a non-randomised observational study investigating whether fatigue significantly reduces peak eccentric strength of the hamstring muscle group. Methods. Twenty-two right leg dominant professional football players participated in this study. None were injured or were rehabilitating from an injury at the time of testing. The eccentric strength of the hamstring muscles was determined using the Nordic exercise on a Norbord device prior to a 90 minute soccer match and after its end. Results. There was a significant decrease in eccentric strength at the end of the match (before the match: M = 306.91, SD = 59.26; after the match: Mean = 277.77 ± SD = 60.35 p =.000, Cohen’s d =.50). The imbalance in eccentric hamstring muscle strength between dominant and non-dominant limb before the match remained unchanged after its end. Conclusions. A professional football match significantly impacts on the ability of players to produce high speed eccentric strength in the hamstring muscle groups. Resistance to fatigue and eccentric strength, particularly at high speeds, are considerable factors in conditioning of professional soccer players. Eccentric muscle strength fatigue of the hamstring muscle group after a 90 min soccer match may provide a possible explanation for the greater risk of hamstring injuries under fatigue conditions. © 2021, CIC Edizioni Internazionali s.r.l.. All rights reserved.
Match-play running demands and technical performance among elite gaelic footballers : does divisional status count?
- McGahan, Jason, Mangan, Shane, Collins, Kieran, Burns, Con, Gabbett, Tim, O'Neill, Cian
- Authors: McGahan, Jason , Mangan, Shane , Collins, Kieran , Burns, Con , Gabbett, Tim , O'Neill, Cian
- Date: 2021
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 35, no. 1 (2021), p. 169-175
- Full Text:
- Reviewed:
- Description: The aim of the current study was to compare positional differences in running demands and technical performance variables among elite Gaelic football teams from separate divisions. Data were obtained from a division 1 (26.7 ± 2.9 years, 179.2 ± 21.3 cm, 89.9 ± 21.2 kg) and a division 3 (25.7 ± 3.5 years, 183.0 ± 4.7 cm, 84.4 ± 6.5 kg) team. Match-play running variables were collected using 4-Hz global positioning system (GPS) units (VX Sport; Visuallex Sport, Lower Hutt, New Zealand) (Match data sets; division 1: n = 107, division 3: n = 97). Selected variables assessed were high-speed running distance (HSR) (
- Authors: McGahan, Jason , Mangan, Shane , Collins, Kieran , Burns, Con , Gabbett, Tim , O'Neill, Cian
- Date: 2021
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 35, no. 1 (2021), p. 169-175
- Full Text:
- Reviewed:
- Description: The aim of the current study was to compare positional differences in running demands and technical performance variables among elite Gaelic football teams from separate divisions. Data were obtained from a division 1 (26.7 ± 2.9 years, 179.2 ± 21.3 cm, 89.9 ± 21.2 kg) and a division 3 (25.7 ± 3.5 years, 183.0 ± 4.7 cm, 84.4 ± 6.5 kg) team. Match-play running variables were collected using 4-Hz global positioning system (GPS) units (VX Sport; Visuallex Sport, Lower Hutt, New Zealand) (Match data sets; division 1: n = 107, division 3: n = 97). Selected variables assessed were high-speed running distance (HSR) (
Investigation in to the positional running demands of elite gaelic football players : how competition data can inform training practice
- McGahan, Jason, Burns, Con, Lacey, Sean, Gabbett, Tim, O'Neil, Cian
- Authors: McGahan, Jason , Burns, Con , Lacey, Sean , Gabbett, Tim , O'Neil, Cian
- Date: 2020
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 34, no. 7 (2020), p. 2040-2047
- Full Text:
- Reviewed:
- Description: This study investigated the positional running demands of elite Gaelic football players during match play and compared these demands with typical training activities used to prepare players for competition. Global positioning system (GPS) data were obtained from 30 elite Gaelic football players (26.9 ± 3.5 years, 182.8 ± 6.1 cm, 84.6 ± 8.1 kg) across a full season (13 competitive games and 78 training sessions). Only players who completed the full match and respective training sessions were included (n = 107 match files and n = 1,603 training files). Data were collected using 4-Hz GPS units (VX Sport, Lower Hutt, New Zealand). Mean high speed (
- Authors: McGahan, Jason , Burns, Con , Lacey, Sean , Gabbett, Tim , O'Neil, Cian
- Date: 2020
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 34, no. 7 (2020), p. 2040-2047
- Full Text:
- Reviewed:
- Description: This study investigated the positional running demands of elite Gaelic football players during match play and compared these demands with typical training activities used to prepare players for competition. Global positioning system (GPS) data were obtained from 30 elite Gaelic football players (26.9 ± 3.5 years, 182.8 ± 6.1 cm, 84.6 ± 8.1 kg) across a full season (13 competitive games and 78 training sessions). Only players who completed the full match and respective training sessions were included (n = 107 match files and n = 1,603 training files). Data were collected using 4-Hz GPS units (VX Sport, Lower Hutt, New Zealand). Mean high speed (
Common high-speed running thresholds likely do not correspond to high-speed running in field sports
- Freeman, Brock, Talpey, Scott, James, Lachlan, Opar, David, Young, Warren
- Authors: Freeman, Brock , Talpey, Scott , James, Lachlan , Opar, David , Young, Warren
- Date: 2023
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 37, no. 7 (2023), p. 1411-1418
- Full Text: false
- Reviewed:
- Description: The purpose of this study was to clarify what percentage of maximum speed is associated with various running gaits. Fifteen amateur field sport athletes (age = 23 ± 3.6 years) participated in a series of 55-meter running trials. The speed of each trial was determined by instructions relating to 5 previously identified gait patterns (jog, run, stride, near maximum sprint, and sprint). Each trial was filmed in slow motion (240 fps), whereas running speed was obtained using Global Positioning Systems. Contact time, stride angle, and midstance free-leg knee angle were determined from video footage. Running gaits corresponded with the following running speeds, jogging = 4.51 m·s-1, 56%Vmax, running = 5.41 m·s-1, 66%Vmax,striding = 6.37 m·s-1, 78%Vmax, near maximum sprinting = 7.08 m·s-1, 87%Vmax, and sprinting = 8.15 m·s-1, 100%Vmax. Significant (p < 0.05) increases in stride angle were observed as running speed increased. Significant (p < 0.05) decreases were observed in contact time and midstance free-leg knee angle as running speed increased. These findings suggest currently used thresholds for high-speed running (HSR) and sprinting most likely correspond with jogging and striding, which likely underestimates the true HSR demands. Therefore, a higher relative speed could be used to describe HSR and sprinting more accurately in field sports. © 2023 NSCA National Strength and Conditioning Association. All rights reserved.
The effects of α-lactalbumin supplementation and handgrip contraction on soleus motoneuron excitability
- Mackay-Phillips, Karen, Orssatto, Lucas, Polman, Remco, Van der Pols, Jolieke, Trajano, Gabriel
- Authors: Mackay-Phillips, Karen , Orssatto, Lucas , Polman, Remco , Van der Pols, Jolieke , Trajano, Gabriel
- Date: 2023
- Type: Text , Journal article
- Relation: European Journal of Applied Physiology Vol. 123, no. 2 (2023), p. 395-404
- Full Text:
- Reviewed:
- Description: Introduction: We tested two strategies that hypothetically increase serotonin availability (
- Description: Introduction: We tested two strategies that hypothetically increase serotonin availability (α-lactalbumin consumption and a remote submaximal handgrip contraction) on estimates of persistent inward currents (PICs) amplitude of soleus muscle in healthy participants. Methods: With a randomised, double-blind, and cross-over design, 13 healthy participants performed triangular-shaped ramp contractions with their plantar flexors (20% of maximal torque), followed by a 30-s handgrip sustained contraction (40% of maximal force) and consecutive repeated triangular-shaped contractions. This was performed before and after the consumption of either 40 g of α-lactalbumin, an isonitrogenous beverage (Zein) or an isocaloric beverage (Corn-starch). Soleus motor units discharge rates were analysed from high-density surface electromyography signals. PICs were estimated by calculating the delta frequency (ΔF) of motor unit train spikes using the paired motor unit technique. Results: ΔF (0.19 pps; p = 0.001; d = 0.30) and peak discharge rate (0.20 pps; p < 0.001; d = 0.37) increased after the handgrip contraction, irrespective of the consumed supplement. No effects of α-lactalbumin were observed. Conclusions: Our results indicate that 40 g of α-lactalbumin was unable to modify intrinsic motoneuron excitability. However, performing a submaximal handgrip contraction before the plantar flexion triangular contraction was capable of increasing ΔF and discharge rates on soleus motor units. These findings highlight the diffused effects of serotonergic input, its effects on motoneuron discharge behaviour, and suggest a cross-effector effect within human motoneurons. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature. Erratum: Correction to: The effects of α‑lactalbumin supplementation and handgrip contraction on soleus motoneuron excitability - The original version of this article unfortunately contained a mistake. The corrected details are given below for your reading. The author’s name Karen Mackay-Phillips was incorrectly written as Karen Mackay Phillips. In section “Overview”, first sentence should read as “The current study was part of an experiment that has been divided in two parts, where some variables are presented in a companion paper (https:// doi. org/ 10. 1007/ s00421- 022- 05103-1).”. © 2022 Springer-Verlag GmbH Germany, part of Springer Nature.
- Authors: Mackay-Phillips, Karen , Orssatto, Lucas , Polman, Remco , Van der Pols, Jolieke , Trajano, Gabriel
- Date: 2023
- Type: Text , Journal article
- Relation: European Journal of Applied Physiology Vol. 123, no. 2 (2023), p. 395-404
- Full Text:
- Reviewed:
- Description: Introduction: We tested two strategies that hypothetically increase serotonin availability (
- Description: Introduction: We tested two strategies that hypothetically increase serotonin availability (α-lactalbumin consumption and a remote submaximal handgrip contraction) on estimates of persistent inward currents (PICs) amplitude of soleus muscle in healthy participants. Methods: With a randomised, double-blind, and cross-over design, 13 healthy participants performed triangular-shaped ramp contractions with their plantar flexors (20% of maximal torque), followed by a 30-s handgrip sustained contraction (40% of maximal force) and consecutive repeated triangular-shaped contractions. This was performed before and after the consumption of either 40 g of α-lactalbumin, an isonitrogenous beverage (Zein) or an isocaloric beverage (Corn-starch). Soleus motor units discharge rates were analysed from high-density surface electromyography signals. PICs were estimated by calculating the delta frequency (ΔF) of motor unit train spikes using the paired motor unit technique. Results: ΔF (0.19 pps; p = 0.001; d = 0.30) and peak discharge rate (0.20 pps; p < 0.001; d = 0.37) increased after the handgrip contraction, irrespective of the consumed supplement. No effects of α-lactalbumin were observed. Conclusions: Our results indicate that 40 g of α-lactalbumin was unable to modify intrinsic motoneuron excitability. However, performing a submaximal handgrip contraction before the plantar flexion triangular contraction was capable of increasing ΔF and discharge rates on soleus motor units. These findings highlight the diffused effects of serotonergic input, its effects on motoneuron discharge behaviour, and suggest a cross-effector effect within human motoneurons. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature. Erratum: Correction to: The effects of α‑lactalbumin supplementation and handgrip contraction on soleus motoneuron excitability - The original version of this article unfortunately contained a mistake. The corrected details are given below for your reading. The author’s name Karen Mackay-Phillips was incorrectly written as Karen Mackay Phillips. In section “Overview”, first sentence should read as “The current study was part of an experiment that has been divided in two parts, where some variables are presented in a companion paper (https:// doi. org/ 10. 1007/ s00421- 022- 05103-1).”. © 2022 Springer-Verlag GmbH Germany, part of Springer Nature.
Effects of α-lactalbumin on strength, fatigue and psychological parameters: a randomised double-blind cross-over study
- Mackay-Phillips, Karen, Orssatto, Lucas, Polman, Remco, Van der Pols, Jolieke, Trajano, Gabriel
- Authors: Mackay-Phillips, Karen , Orssatto, Lucas , Polman, Remco , Van der Pols, Jolieke , Trajano, Gabriel
- Date: 2023
- Type: Text , Journal article
- Relation: European Journal of Applied Physiology Vol. 123, no. 2 (2023), p. 381-393
- Full Text:
- Reviewed:
- Description: Purpose: The neurotransmitter serotonin has a strong effect on behaviour and motor control. Regarding motor control, serotonin contributes to the development of fatigue and is also involved in the ability of motor neurones to operate across a large range of forces (gain control). The consumption of tryptophan-rich supplements (such as
- Description: Purpose: The neurotransmitter serotonin has a strong effect on behaviour and motor control. Regarding motor control, serotonin contributes to the development of fatigue and is also involved in the ability of motor neurones to operate across a large range of forces (gain control). The consumption of tryptophan-rich supplements (such as α-lactalbumin) is of interest because this amino acid is the only precursor for brain serotonin synthesis. Therefore, the purpose of this study was to determine the effects of α-lactalbumin supplementation on neuromuscular performance. Methods: Using a randomised double-blind cross-over design, 16 healthy participants performed plantar flexor and handgrip maximal voluntary contractions, a 30-s submaximal handgrip contraction, and a plantar flexor fatigue protocol before and 90 min after consuming either 40 g of α-lactalbumin, an isonitrogenous beverage (Zein) or an isocaloric beverage (corn-starch). Sleepiness, mood, and cognition were assessed to evaluate any psychological effects. Results: α-Lactalbumin decreased force steadiness by 25% during the sustained submaximal handgrip contraction (p < 0.01) and induced greater fatigue (15% reduction in total torque–time integral, p = 0.01) during the fatigue protocol. These effects were not observed for the other control beverages. No effects were found for maximal or explosive strength, or psychological measurements. Conclusions: 40 g of α-lactalbumin increased handgrip force variability and reduced performance during fatiguing muscle contractions but did not influence brief maximal contractions or psychological parameters in healthy individuals. These findings support the hypothesis that the consumption of α-lactalbumin can increase motor neurone input–output gain and exacerbate central fatigue during sustained maximal exercise. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
- Authors: Mackay-Phillips, Karen , Orssatto, Lucas , Polman, Remco , Van der Pols, Jolieke , Trajano, Gabriel
- Date: 2023
- Type: Text , Journal article
- Relation: European Journal of Applied Physiology Vol. 123, no. 2 (2023), p. 381-393
- Full Text:
- Reviewed:
- Description: Purpose: The neurotransmitter serotonin has a strong effect on behaviour and motor control. Regarding motor control, serotonin contributes to the development of fatigue and is also involved in the ability of motor neurones to operate across a large range of forces (gain control). The consumption of tryptophan-rich supplements (such as
- Description: Purpose: The neurotransmitter serotonin has a strong effect on behaviour and motor control. Regarding motor control, serotonin contributes to the development of fatigue and is also involved in the ability of motor neurones to operate across a large range of forces (gain control). The consumption of tryptophan-rich supplements (such as α-lactalbumin) is of interest because this amino acid is the only precursor for brain serotonin synthesis. Therefore, the purpose of this study was to determine the effects of α-lactalbumin supplementation on neuromuscular performance. Methods: Using a randomised double-blind cross-over design, 16 healthy participants performed plantar flexor and handgrip maximal voluntary contractions, a 30-s submaximal handgrip contraction, and a plantar flexor fatigue protocol before and 90 min after consuming either 40 g of α-lactalbumin, an isonitrogenous beverage (Zein) or an isocaloric beverage (corn-starch). Sleepiness, mood, and cognition were assessed to evaluate any psychological effects. Results: α-Lactalbumin decreased force steadiness by 25% during the sustained submaximal handgrip contraction (p < 0.01) and induced greater fatigue (15% reduction in total torque–time integral, p = 0.01) during the fatigue protocol. These effects were not observed for the other control beverages. No effects were found for maximal or explosive strength, or psychological measurements. Conclusions: 40 g of α-lactalbumin increased handgrip force variability and reduced performance during fatiguing muscle contractions but did not influence brief maximal contractions or psychological parameters in healthy individuals. These findings support the hypothesis that the consumption of α-lactalbumin can increase motor neurone input–output gain and exacerbate central fatigue during sustained maximal exercise. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
- «
- ‹
- 1
- ›
- »