Research article
Carbohydrate vs protein supplementation for recovery of neuromuscular function following prolonged load carriage
-
* Corresponding author: Mark ET Willems m.willems@chi.ac.uk
1 University of Chichester, Faculty of Sport, Education and Social Sciences, West Sussex, UK
2 Institute of Naval Medicine, Gosport, Hampshire, UK
3 University of Bath, School for Health, Bath, UK
Journal of the International Society of Sports Nutrition 2010, 7:2 doi:10.1186/1550-2783-7-2
Published: 12 January 2010Abstract
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, 
O2max: 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°·s-1) recovered to pre-exercise values at 72 h. Trunk extensor and flexor peak torque (15°·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.