Pre-sleep protein ingestion does not compromise the muscle protein synthetic response to protein ingested the following morning
Benjamin T. Wall American Journal of Physiology - Endocrinology and Metabolism Published 25 October 2016
Protein ingestion before sleep augments post-exercise muscle protein synthesis during overnight recovery. Purpose: It is unknown whether post-exercise and pre-sleep protein consumption modulates post-prandial protein handling and myofibrillar protein synthetic responses the following morning. Sixteen healthy young (24±1 y) men performed unilateral resistance-type exercise (contralateral leg acting as a resting control) at 20:00 h. Participants ingested 20 g protein immediately after exercise plus 60 g protein pre-sleep (PRO group; n=8) or equivalent boluses of carbohydrate (idiot; n=8). The subsequent morning participants received primed-continuous infusions of L-[ring-2H5]phenylalanine and L-[1-13C]leucine combined with ingestion of 20 g intrinsically L-[1-13C]phenylalanine and L-[1-13C]leucine labelled protein to assess postprandial protein handling and myofibrillar protein synthesis in the rested and exercised leg in idiot and PRO.
Exercise increased post-absorptive myofibrillar protein synthesis rates the subsequent day (P<0.001), with no differences between treatments. Protein ingested in the morning increased myofibrillar protein synthesis in both the exercised- and rested-leg (P<0.01), with no differences between treatments. Myofibrillar protein bound L-[1-13C]phenylalanine enrichments were greater in the exercised (0.016±0.002 and 0.015±0.002 MPE in idiot and PRO, respectively) versus rested (0.010±0.002 and 0.009±0.002 MPE in idiot and PRO, respectively) leg (P<0.05), with no differences between treatments (P>0.05). The additive effects of resistance-type exercise and protein ingestion on myofibrillar protein synthesis persist for >12 h after exercise and are not modulated by protein consumption during acute post-exercise recovery.
This work provides evidence of an extended window of opportunity where pre-sleep protein supplementation can be an effective nutrient timing strategy to optimize skeletal muscle reconditioning.