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Carbohydrate vs protein supplementation for recovery of neuromuscular function following prolonged load carriage.

Blacker SD, Williams NC, Fallowfield JL, Bilzon JLj, Willems ME - J Int Soc Sports Nutr (2010)

Bottom Line: Isometric knee extension force decreased immediately after load carriage with no difference between conditions.Voluntary activation decreased immediately after load carriage and returned to pre-exercise values at 24 h in all conditions (P = 0.086).Following reductions immediately after load carriage, knee extensor and flexor peak torque (60 degrees .s(-1)) recovered to pre-exercise values at 72 h.

View Article: PubMed Central - HTML - PubMed

Affiliation: University of Chichester, Faculty of Sport, Education and Social Sciences, West Sussex, UK.

ABSTRACT

Background: This study examined the effect of carbohydrate and whey protein supplements on recovery of neuromuscular function after prolonged load carriage.

Methods: TEN MALE PARTICIPANTS (BODY MASS: 81.5 +/- 10.5 kg, age: 28 +/- 9 years, O(2)max: 55.0 +/- 5.5 ml.kg(-1).min(-1)) completed three treadmill walking tests (2 hr, 6.5 km.h(-1)), carrying a 25 kg backpack consuming 500 ml of either: (1) Placebo (flavoured water) [PLA], (2) 6.4% Carbohydrate Solution [CHO] or (3) 7.0% Whey Protein Solution [PRO]. For three days after load carriage, participants consumed two 500 ml supplement boluses. Muscle performance was measured before and at 0, 24, 48 and 72 h after load carriage, during voluntary and electrically stimulated contractions.

Results: Isometric knee extension force decreased immediately after load carriage with no difference between conditions. During recovery, isometric force returned to pre-exercise values at 48 h for CHO and PRO but at 72 h for PLA. Voluntary activation decreased immediately after load carriage and returned to pre-exercise values at 24 h in all conditions (P = 0.086). During recovery, there were no differences between conditions for the change in isokinetic peak torque. Following reductions immediately after load carriage, knee extensor and flexor peak torque (60 degrees .s(-1)) recovered to pre-exercise values at 72 h. Trunk extensor and flexor peak torque (15 degrees .s(-1)) recovered to pre-exercise values at 24 h (P = 0.091) and 48 h (P = 0.177), respectively.

Conclusion: Recovery of neuromuscular function after prolonged load carriage is improved with either carbohydrate or whey protein supplementation for isometric contractions but not for isokinetic contractions.

No MeSH data available.


Related in: MedlinePlus

Peak torque of the knee flexors during isokinetic contractions (60°·s-1) Measurements were made before and after (0, 24, 48 and 72 h) 120 minutes of treadmill walking at 6.5 km·h-1 (n = 10) on a level gradient (0%) carrying a 25 kg backpack with consumption of 250 ml (at 0 and 60 minutes) of a beverage containing either placebo (PLA - Black square), carbohydrate (6.4%) (CHO - Black triangle) or protein (7%) (PRO - Black circle) and twice daily (500 ml, morning and evening) for the 3 days after load carriage (n = 10). Symbols show difference from pre measurement for PLA (* P < 0.05), CHO († P < 0.05), PRO (# P < 0.05).
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Figure 3: Peak torque of the knee flexors during isokinetic contractions (60°·s-1) Measurements were made before and after (0, 24, 48 and 72 h) 120 minutes of treadmill walking at 6.5 km·h-1 (n = 10) on a level gradient (0%) carrying a 25 kg backpack with consumption of 250 ml (at 0 and 60 minutes) of a beverage containing either placebo (PLA - Black square), carbohydrate (6.4%) (CHO - Black triangle) or protein (7%) (PRO - Black circle) and twice daily (500 ml, morning and evening) for the 3 days after load carriage (n = 10). Symbols show difference from pre measurement for PLA (* P < 0.05), CHO († P < 0.05), PRO (# P < 0.05).

Mentions: Peak torque (60°·s-1) of knee flexors changed over time (P < 0.001) but there was no difference between conditions (P = 0.762) (Figure 3). Knee flexor peak torque (60°·s-1) decreased below pre-exercise value (P < 0.001) and remained suppressed at 24 h (P = 0.001) and 48 h (P = 0.012) fully recovering by 72 h (P = 0.109). Knee flexor peak torque (180°·s-1) decreased immediately after load carriage in all conditions (P = 0.010) and fully recovered 24 h (P = 0.397) remaining at pre-exercise value for all conditions at 48 and 72 h (P > 0.05). There was no difference between conditions (P = 0.481).


Carbohydrate vs protein supplementation for recovery of neuromuscular function following prolonged load carriage.

Blacker SD, Williams NC, Fallowfield JL, Bilzon JLj, Willems ME - J Int Soc Sports Nutr (2010)

Peak torque of the knee flexors during isokinetic contractions (60°·s-1) Measurements were made before and after (0, 24, 48 and 72 h) 120 minutes of treadmill walking at 6.5 km·h-1 (n = 10) on a level gradient (0%) carrying a 25 kg backpack with consumption of 250 ml (at 0 and 60 minutes) of a beverage containing either placebo (PLA - Black square), carbohydrate (6.4%) (CHO - Black triangle) or protein (7%) (PRO - Black circle) and twice daily (500 ml, morning and evening) for the 3 days after load carriage (n = 10). Symbols show difference from pre measurement for PLA (* P < 0.05), CHO († P < 0.05), PRO (# P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2821364&req=5

Figure 3: Peak torque of the knee flexors during isokinetic contractions (60°·s-1) Measurements were made before and after (0, 24, 48 and 72 h) 120 minutes of treadmill walking at 6.5 km·h-1 (n = 10) on a level gradient (0%) carrying a 25 kg backpack with consumption of 250 ml (at 0 and 60 minutes) of a beverage containing either placebo (PLA - Black square), carbohydrate (6.4%) (CHO - Black triangle) or protein (7%) (PRO - Black circle) and twice daily (500 ml, morning and evening) for the 3 days after load carriage (n = 10). Symbols show difference from pre measurement for PLA (* P < 0.05), CHO († P < 0.05), PRO (# P < 0.05).
Mentions: Peak torque (60°·s-1) of knee flexors changed over time (P < 0.001) but there was no difference between conditions (P = 0.762) (Figure 3). Knee flexor peak torque (60°·s-1) decreased below pre-exercise value (P < 0.001) and remained suppressed at 24 h (P = 0.001) and 48 h (P = 0.012) fully recovering by 72 h (P = 0.109). Knee flexor peak torque (180°·s-1) decreased immediately after load carriage in all conditions (P = 0.010) and fully recovered 24 h (P = 0.397) remaining at pre-exercise value for all conditions at 48 and 72 h (P > 0.05). There was no difference between conditions (P = 0.481).

Bottom Line: Isometric knee extension force decreased immediately after load carriage with no difference between conditions.Voluntary activation decreased immediately after load carriage and returned to pre-exercise values at 24 h in all conditions (P = 0.086).Following reductions immediately after load carriage, knee extensor and flexor peak torque (60 degrees .s(-1)) recovered to pre-exercise values at 72 h.

View Article: PubMed Central - HTML - PubMed

Affiliation: University of Chichester, Faculty of Sport, Education and Social Sciences, West Sussex, UK.

ABSTRACT

Background: This study examined the effect of carbohydrate and whey protein supplements on recovery of neuromuscular function after prolonged load carriage.

Methods: TEN MALE PARTICIPANTS (BODY MASS: 81.5 +/- 10.5 kg, age: 28 +/- 9 years, O(2)max: 55.0 +/- 5.5 ml.kg(-1).min(-1)) completed three treadmill walking tests (2 hr, 6.5 km.h(-1)), carrying a 25 kg backpack consuming 500 ml of either: (1) Placebo (flavoured water) [PLA], (2) 6.4% Carbohydrate Solution [CHO] or (3) 7.0% Whey Protein Solution [PRO]. For three days after load carriage, participants consumed two 500 ml supplement boluses. Muscle performance was measured before and at 0, 24, 48 and 72 h after load carriage, during voluntary and electrically stimulated contractions.

Results: Isometric knee extension force decreased immediately after load carriage with no difference between conditions. During recovery, isometric force returned to pre-exercise values at 48 h for CHO and PRO but at 72 h for PLA. Voluntary activation decreased immediately after load carriage and returned to pre-exercise values at 24 h in all conditions (P = 0.086). During recovery, there were no differences between conditions for the change in isokinetic peak torque. Following reductions immediately after load carriage, knee extensor and flexor peak torque (60 degrees .s(-1)) recovered to pre-exercise values at 72 h. Trunk extensor and flexor peak torque (15 degrees .s(-1)) recovered to pre-exercise values at 24 h (P = 0.091) and 48 h (P = 0.177), respectively.

Conclusion: Recovery of neuromuscular function after prolonged load carriage is improved with either carbohydrate or whey protein supplementation for isometric contractions but not for isokinetic contractions.

No MeSH data available.


Related in: MedlinePlus