Effect of carbohydrate-protein supplement timing on acute exercise-induced muscle damage

Abstract

PurposeTo determine if timing of a supplement would have an effect on muscle damage, function and soreness.MethodsTwenty-seven untrained men (21 ± 3 yrs) were given a supplement before or after exercise. Subjects were randomly assigned to a pre exercise (n = 9), received carbohydrate/protein drink before exercise and placebo after, a post exercise (n = 9), received placebo before exercise and carbohydrate/protein drink after, or a control group (n = 9), received placebo before and after exercise. Subjects performed 50 eccentric quadriceps contractions on an isokinetic dynamometer. Tests for creatine kinase (CK), maximal voluntary contraction (MVC) and muscle soreness were recorded before exercise and at six, 24, 48, 72, and 96 h post exercise. Repeated measures ANOVA were used to analyze data.ResultsThere were no group by time interactions however, CK significantly increased for all groups when compared to pre exercise (101 ± 43 U/L) reaching a peak at 48 h (661 ± 1178 U/L). MVC was significantly reduced at 24 h by 31.4 ± 14.0%. Muscle soreness was also significantly increased from pre exercise peaking at 48 h.ConclusionEccentric exercise caused significant muscle damage, loss of strength, and soreness; however timing of ingestion of carbohydrate/protein supplement had no effect.

Co-ingestion of carbohydrate and pea protein does not enhance muscle recovery after strenuous exercise

“…Additionally, in accordance to our study, White et al 2 , Breen et al 18 , Betts et al 19 , and Green et al 20 showed that the co-ingestion of CHO and PRO does not improve the recovery of isometric force.…”

“…That is because most studies showing significant effects have maximum CK levels between 250 and 600 U/L 10,11,14,35 , while those showing no significant effects have typically reported peak CK levels in the 1000-1400 U/L region 2,20 . Considering that the subjects in the present study already had high plasma CK before the LRT, it is reasonable to suppose that our results could have been influenced by this fact, which makes comparison particularly difficult since in other studies subjects usually had normal CK before performing physical tests.…”

The efficacy of protein supplementation during recovery from muscle-damaging concurrent exercise

“…Much of the research relating to EIMD suffers from a limitation, which is often acknowledged, in that there is a lack of control concerning habitual diet (Cockburn et al, 2008, Howatson et al, 2012, White et al, 2008. This is problematic on two counts; with underlying discrepancies in macronutrient intake affecting bioavailability of a given substrate and a likely variance in the energy balance within or between experimental groups.…”

“…The evidence is equivocal, with research suggesting efficacy (Cockburn et al, 2008, Etheridge et al, 2008, Hoffman et al, 2010) and a lack of benefits (Green et al, 2008, White et al, 2008, Wojcik et al, 2001) for protein or coingested-protein supplementation to attenuate indices of EIMD. Fractional synthesis rates and fractional net balance are still elevated at 48 h following resistance exercise (Phillips et al, 1997).…”

Nutritional strategies for post-exercise recovery: a review

“…29,30 Elevated levels of these enzymatic markers are associated with decreased performance. 30 Due to the applied nature of recovery studies, the majority of the literature examining muscle damage has included multiple indicators of muscle damage: bloodborne creatine kinase (CK), subjective measures of muscle soreness (using a visual scale). 31 However, CK has been criticised as an effective indicator of muscle damage because of poor correlations with direct measures of muscle damage.…”