Effect of whey vs. soy protein supplementation on recovery kinetics following speed endurance training in competitive male soccer players: a randomized controlled trial

Abstract

Background Soccer-specific speed-endurance training induces short-term neuromuscular fatigue and performance deterioration over a 72-h recovery period, associated with elevated markers of exercise-induced muscle damage. We compared the effects of whey vs. soy protein supplementation on field activity, performance, muscle damage and redox responses following speed-endurance training in soccer players. Methods Ten well-trained, male soccer players completed three speed-endurance training trials, receiving whey protein (WP), soy protein (SP) or an isoenergetic placebo (PL; maltodextrin) according to a randomized, double-blind, crossover, repeated-measures design. A pre-loading period was applied in each trial during which protein supplementation was individually adjusted to reach a total protein intake of 1.5 g/kg/day, whereas in PL protein intake was adjusted at 0.8–1 g/kg/day. Following pre-loading, two speed-endurance training sessions (1 and 2) were performed 1 day apart, over a 3-day experimental period. During each session, field activity and heart rate were continuously monitored using global positioning system and heart rate monitors, respectively. Performance (isokinetic strength of knee extensors and flexors, maximal voluntary isometric contraction, speed, repeated sprint ability, countermovement jump), muscle damage (delayed-onset of muscle soreness, creatine kinase activity) and redox status (glutathione, total antioxidant capacity, protein carbonyls) were evaluated at baseline (pre), following pre-loading (post-load), and during recovery from speed-endurance training. Results High-intensity and high-speed running decreased (P ≤ 0.05) during speed-endurance training in all trials, but WP and SP mitigated this response. Isokinetic strength, maximal voluntary isometric contraction, 30-m speed, repeated sprint ability and countermovement jump performance were similarly deteriorated during recovery following speed-endurance training in all trials (P ≤ 0.05). 10 m speed was impaired at 24 h only in PL. Delayed-onset of muscle soreness, creatine kinase, total antioxidant capacity and protein carbonyls increased and glutathione decreased equally among trials following speed-endurance training (P ≤ 0.05), with SP inducing a faster recovery of protein carbonyls only at 48 h (P ≤ 0.05) compared to WP and PL. Conclusions In conclusion, increasing daily protein intake to 1.5 g/kg through ingestion of either whey or soy protein supplements mitigates field performance deterioration during successive speed-endurance training sessions without affecting exercise-induced muscle damage and redox status markers. Trial registration Name of the registry: clinicaltrials.gov. Trial registration: NCT03753321. Date of registration: 12/10/2018.

The Effects of Dietary Protein Supplementation on Exercise-Induced Inflammation and Oxidative Stress: A Systematic Review of Human Trials

“…Of the 34 included studies, 19 used a parallel group design [ 48 , 49 , 51 , 52 , 53 , 54 , 55 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 ], 3 had three treatment arms [ 52 , 54 , 63 ], and 2 had four treatment arms [ 68 , 74 ]. The remaining 15 studies employed a crossover design [ 8 , 30 , 50 , 56 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 ], three of which had three treatment arms [ 50 , 80 , 81 ].…”

“…The mean age of all the participants was 24 years, with an age range of 19–40 years. Nineteen studies recruited healthy athletes or highly trained professionals [ 8 , 30 , 48 , 50 , 55 , 56 , 65 , 70 , 71 , 74 , 76 , 77 , 78 , 79 , 80 , 82 , 83 , 84 , 85 ], and nine studies were conducted on recreationally active participants or participants that habitually performed resistance exercise training 1 to 2 days a week [ 51 , 53 , 54 , 66 , 67 , 69 , 72 , 73 , 81 ]. Six studies were on untrained participants [ 49 , 52 , 63 , 64 , 68 , 75 ].…”

“…Whey protein. Of the twelve studies with whey protein supplementation, only two demonstrated favorable anti-inflammatory or antioxidant effects [ 30 , 50 ], with the remaining ten reporting no effects [ 51 , 54 , 63 , 66 , 75 , 76 , 78 , 80 , 81 , 82 ].…”

“…Whey protein isolate. Seven studies examined the effect of whey protein isolate on markers of exercise-induced inflammation and oxidative stress; none of them reported changes with the intervention [ 54 , 63 , 66 , 75 , 76 , 80 , 82 ]. In Baba et al [ 75 ], whey protein isolate (22.8 g) before, during, and after exercise did not attenuate IL-6 4 h post-exercise ( p = 0.055).…”

A new generation of soy proteins for sustainable food production

“…Soy contains in its composition a significant amount of high-value protein, dietary fiber, minerals that determine its nutritional value and attract numerous researchers to find the most effective ways to use soy and its processed products in order to create new types of functional products and increase their nutritional value [9]. Soy proteins are traditionally produced in various forms: soy flour, soy protein concentrate, and soy protein isolate.…”