Coingestion of protein and carbohydrate in the early recovery phase, compared with carbohydrate only, improves endurance performance despite similar glycogen degradation and AMPK phosphorylation
Research output: Contribution to journal › Journal article › Research › peer-review
The present study compared the effects of post exercise carbohydrate plus protein (CHO+PROT) and carbohydrate (CHO) only supplementation on muscle glycogen metabolism, anabolic cell signalling and subsequent exercise performance. Nine endurance-trained males cycled twice to exhaustion (muscle glycogen decreased from ~495 to ~125 mmol·kg dw-1) and received either CHO only (1.2 g·kg-1·h-1) or CHO+PROT (0.8/0.4 g·kg-1·h-1) during the first 90 min of recovery. Glycogen content was similar before the performance test after 5 h of recovery. Glycogen synthase (GS) fractional activity increased after exhaustive exercise and remained activated 5 h after despite substantial glycogen synthesis (176.1±19.1 and 204.6±27.0 mmol·kg dw-1 in CHO and CHO+PROT, respectively; p=0.15). Phosphorylation of GS at site 3 and site 2+2a remained low during recovery. After the 5 h recovery, cycling time to exhaustion was improved by CHO+PROT supplementation compared to CHO supplementation (54.6±11.0 vs 46.1±9.8 min; p=0.009). After the performance test, muscle glycogen was equally reduced in PRO+CHO and CHO. Akt Ser473 and p70s6k Thr389 phosphorylation was elevated after 5 h of recovery. There were no differences in Akt Ser473, p70s6k Thr389 or TSC2 Thr1462 phosphorylation between treatments. Nitrogen balance was positive in CHO+PROT (19.6±7.6 mg nitrogen·kg-1, p=0.04) and higher than CHO (-10.7±6.3 mg nitrogen·kg-1, p=0.009).
Conclusion: CHO+PROT supplementation during exercise recovery improved subsequent endurance performance relative to consuming CHO only. This improved performance after CHO+PROT supplementation could not be accounted for by differences in glycogen metabolism or anabolic cell signaling, but may have been related to differences in nitrogen balance.
|Journal||Journal of Applied Physiology|
|Number of pages||14|
|Publication status||Published - 2020|
- Faculty of Science - Exercise, Glycogen synthase, Akt/PKB, Protein synthesis, Nitrogen balance