Adding protein to a carbohydrate supplement

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The below may be of interest:

Adding protein to a carbohydrate supplement provided after endurance

exercise enhances 4E-BP1 and RPS6 signaling in skeletal muscle

J. on, Daisuke Hara, Zhenping Ding, and L. Ivy

J Appl Physiol 104: 1029-1036, 2008. First published January 31,

2008; doi:10.1152/japplphysiol.01173.2007

8750-7587/08 $8.00

To examine the role of both endurance exercise and nutrient

supplementation on the activation of mRNA translation signaling

pathways postexercise, rats were subjected to a 3-h swimming

protocol. Immediately following exercise, the rats were provided with

a solution containing either 23.7% wt/vol carbohydrates (CHO), 7.9%

wt/vol protein (Pro), 31.6% wt/vol (23.7% wt/vol CHO + 7.9% wt/vol

Pro) carbohydrates and Pro (CP), or a placebo (EX). The rats were

then killed at 0, 30, and 90 min postexercise, and phosphorylation

states of mammalian target of rapamycin (mTOR), ribosomal S6 kinase

(p70S6K), ribosomal protein S6 (rpS6), and 4E-binding protein 1 (4E-

BP1), were analyzed by immunoblot analysis in the red and white

quadriceps muscle. Results demonstrated that rat groups provided with

any of the three nutritional supplements (CHO, Pro, CP) transiently

increased the phosphorylation states of mTOR, 4E-BP1, rpS6, and

p70S6K compared with EX rats. Although CHO, Pro, and CP supplements

phosphorylated mTOR and p70S6K after exercise, only CP elevated the

phosphorylation of rpS6 above all other supplements 30 min

postexercise and 4E-BP1 30 and 90 min postexercise. Furthermore, the

phosphorylation states of 4E-BP1 (r2 = 0.7942) and rpS6 (r2 = 0.760)

were highly correlated to insulin concentrations in each group.

These results suggest that CP supplementation may be most effective

in activating the mTOR-dependent signaling pathway in the

postprandial state postexercise, and that there is a strong

relationship between the insulin concentration and the activation of

enzymes critical for mRNA translation.

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Carruthers

Wakefield, UK