Proceedings of the Fourteenth International Society of Sports Nutrition (ISSN) Conference and Expo

Proceedings of the Fourteenth International Society of Sports Nutrition (ISSN) Conference and Expo

Correspondence: Vincent Martin

Background

Electrostimulation training (ES) can increase muscle power, but this aggressive modality of training may also increase muscle fatigue and possibly delay recovery (1). It has been demonstrated that Native whey (NW) supplementation, may reduce neuromuscular fatigue induced by strength training programs (2, 3).

The aim of this study was therefore to evaluate the impact of NW supplementation and a training program consisting in ES and voluntary training, on recovery and training gains.

Material and methods

Forty-two moderately active men (21.5±3.2 years) were involved in this pilot, double-blinded trial and followed a 12-week training program; 6 weeks ES (3/week) and 6 weeks ES combined with plyometric and sprint training sessions (2-3/week). They were randomly allocated into 3 groups supplemented 5d/week with one of three isocaloric beverages; 30 g of carbohydrates (Control), or 15 g of carbohydrates and 15 g of protein from NW or from standard whey protein isolate (WPI).

Recovery of maximal concentric power (Pmax) was measured before, immediately after, and 30 min, 60 min, 24 h, 48 h after three ES sessions; the first (at week1 (W1)), the fourth (W2) and last (W12). Muscle performance was evaluated before (W0), after 6 (W6) and 12 weeks of training (W12); maximal voluntary contraction force (CMV), evoked twitch amplitude (Pt), anatomical cross-sectional area (CSA) and maximal voluntary activation level (VAL) of the knee extensors were measured.

Results

Pmax recovery was initiated at 30 min in NW, 24 h in WPI and 48 h in Control (P<0.01). Training gains also differed between groups, with CMV increase between W0 and W12 by +11.8% in NW (P<0.001), +7.1% in WPI (P<0.05), and no change in Control. However, between W6 and W12, only NW showed gains in CMV. VAL remained unchanged in NW throughout the follow-up, while it decreased at W12 in WPI (-3.5%, P<0.05), and at W6 and W12 in Control (-3.9%, P<0.05). Pt and CSA improved as a result of training, and did not differ between groups.

Conclusions

As suggested by these results, NW, as compared to WPI and Control, initiates power recovery process earlier. The strength gains observed along the entire training period in NW are possibly associated with this early recovery process, and could be explained not only by the muscle hypertrophy observed in all groups, but also by the preserved VAL, that decreased in WPI and Control, suggesting that overtraining occurred in these 2 groups

Author Disclosure Information

V. Martin : Contracted Research – Including Principle Investigator;

Study funded by Lactalis Ingredients.

References

1. Zory RF, Jubeau MM, and Maffiuletti NA : Contractile impairment after quadriceps strength training via electrical stimulation. Journal of strength and conditioning research 2010, 24(2):458-64.

2. Babault N, Deley G, Le Ruyet P, Morgan F, and Allaert FA : Effects of soluble milk protein or casein supplementation on muscle fatigue following resistance training program: a randomized, double-blind, and controlcebo-controlled study. Journal of the International Society of Sports Nutrition 2014, 11-36.

3. Gryson C, Ratel S, Rance M, Penando S, Bonhomme C, Le Ruyet P, Duclos M, Boirie Y, and Walrand S : Four-month course of soluble milk proteins interacts with exercise to improve muscle strength and delay fatigue in elderly participants. Journal of the American Medical Directors Association 2014, 15(12):958e1-9.