Effect of dietary protein content during recovery from high-intensity cycling on subsequent performance and markers of stress, inflammation, and muscle damage in well-trained men

Abstract

Nutrition is an important aspect of recuperation for athletes during multi-day competition or hard training. Post-exercise carbohydrate is likely to improve recovery, but the effect of protein is equivocal. The objective of this study was to determine the effect of post-exercise dietary protein content imposed over a high-carbohydrate background on subsequent performance. Using a crossover design, 12 cyclists completed 3 high-intensity rides over 4 days. Day 1 comprised 2.5 h intervals, followed by repeat-sprint performance tests on days 2 (15 h post) and 4 (60 h post), interspersed with a rest day. During 4 h recovery on days 1 and 2, cyclists ingested either 1.4 g.kg(-1).h(-1) carbohydrate, 0.7 g.kg(-1).h(-1) protein and 0.26 g.kg(-1).h(-1) fat (protein-enriched) or 2.1 g.kg(-1).h(-1) carbohydrate, 0.1 g.kg(-1).h(-1) protein, and equal fat (control). At other times, cyclists ingested a standardized high-carbohydrate diet. Anabolism was gauged indirectly by nitrogen balance, stress and inflammation via cortisol and cytokines, skeletal-muscle membrane disruption by creatine kinase, and oxidative stress by malonyl dealdehyde. Sprint mean power was not clearly different on day 2 (0.0%; 95%CL: +/-3.9%), but on day 4 it was 4.1% higher (+/-4.1%) in the protein-enriched condition relative to control. Reduced creatine kinase was possible (26%; +/-30%) but effects on oxidative stress, inflammatory markers, and cortisol were inconclusive or trivial. Overnight nitrogen balance was positive in the protein-enriched condition on day 1 (249+/-70 mg N.kg FFM(-1); mean+/-SD), but negative (-48+/-26 mg N.kg FFM(-1)) in the control condition. A nutritive effect of post-exercise protein content was not discernible short term (15 h), but a delayed performance benefit (60 h) was observed following protein-enriched high-carbohydrate ingestion.

Curcumin supplementation likely attenuates delayed onset muscle soreness (DOMS)

“…>5 %) (Hopkins et al 2009). Readers are referred elsewhere for published descriptions, examples, and statistical rationale for magnitude-based inference (Rowlands et al 2008a(Rowlands et al , 2014Batterham and Hopkins 2006;Hopkins 2006).…”

“…Other nutritional supplements with antioxidant or anti-inflammatory properties have also been shown to lower post-exercise muscle soreness and damage markers. These supplements include: dairy protein (Rowlands et al 2008b;Saunders 2007;Cockburn et al 2008;Cooke et al 2010) and tart cherries (Howatson et al 2009;Kuehl et al 2010). Other supplements with antioxidant or anti-inflammatory properties include exotic berries (acai, goji), quercetin, green tea and fish oils; however, there appears to be reduced translation in benefits from rodents to well-trained humans (Nieman et al 2012).…”

l-Arginine but not l-glutamine likely increases exogenous carbohydrate oxidation during endurance exercise

“…The baseline score was included as a covariate adjustment for the analysis of the psychometric data. Inferences about the population values of statistics were made via magnitude-based inference (Hopkins et al 2009) using the methodology described recently (Rowlands et al 2008a). Uncertainty was presented as 90% confidence limits (CL).…”

Protein-leucine ingestion activates a regenerative inflammo-myogenic transcriptome in skeletal muscle following intense endurance exercise

“…muscle functional plasticity (23,57,71), work performance (16,23,32,56,60,66), and metabolic health (3,35,59). In humans, improved muscle performance following postexercise protein or amino acid ingestion was associated with increased myofibrillar protein fractional synthesis rate (FSR) in the first 3-4 h postexercise (11,24) and evidence for reduced muscle damage 24 -48 h later (lower blood creatine kinase) (42,56,60,66).…”

“…In humans, improved muscle performance following postexercise protein or amino acid ingestion was associated with increased myofibrillar protein fractional synthesis rate (FSR) in the first 3-4 h postexercise (11,24) and evidence for reduced muscle damage 24 -48 h later (lower blood creatine kinase) (42,56,60,66). Myofibrillar protein turnover may be an important component of muscle plasticity to exercise (23).…”