Ying Jiao

Protein supplementation enhances cerebral oxygenation during exercise in elite basketball players

OBJECTIVEnThe aim of the present study was to examine cerebral oxygenation during high-intensity exercise in elite basketball players who consumed supplements with different whey protein contents after a short postexercise recovery to determine whether changing whey protein content in carbohydrate-based supplementation influences cerebral hemodynamic response when the supplement was consumed during a 2-h recovery after a 1-h exercise challenge.nnnMETHODSnThis was a randomized, counterbalanced crossover study. Fifteen Division 1 collegiate basketball players (18-20u2009y) consumed 6.25u2009kcal/kg of either high-protein (36% protein in total calorie) or an isocaloric low-protein (12% protein in total calorie) control supplement in a carbohydrate-based drink immediately after a 1-h cycling (70% of maximal oxygen consumption [VO2max]). After a 2-h rest, the athletes were challenged on a cycloergometer at 80% VO2max. Blood perfusion (total hemoglobin) and oxygen saturation of frontal brain were continuously measured by near-infrared spectroscopy during the cycling.nnnRESULTSnBefore the cycloergometer test, high-protein supplementation increased peak insulin response and lowered glucose increases during the recovery compared with the low-protein trial. High-protein supplementation enhanced increases in cerebral oxygen saturation (Pu2009<u20090.01) and attenuated increases in cerebral blood perfusion (total hemoglobin; Pu2009<u20090.01) during the cycloergometer exercise; and resulted in a 16% longer cycling time (from 474u2009±u200949u2009s to 553u2009±u200978u2009s, Pu2009<u20090.05), compared with the low-protein trial.nnnCONCLUSIONnEnhanced fatigue recovery after consumption of a high-protein supplement is associated with enhanced cerebral oxygenation against exercise challenge, which spares brain blood demand for periphery.

Aged cells in human skeletal muscle after resistance exercise

It remains unclear how exercise, as an entropic event, brings benefit against human aging. Here we examined longitudinal changes of p16Ink4a+ senescent cells in skeletal muscle of young men (aged 22.5±1.7 y) before and after resistance exercise (0 h and 48 h) with multiple biopsies at two different protein availabilities: low protein (14%) and isocaloric high protein (44%) supplemented conditions. Immunohistochemistry analysis of muscle cross-sections using p16Ink4a and CD34 antibodies confirmed that the detected senescent cells were endothelial progenitor cells. Leukocyte infiltration into skeletal muscle increased during resistance exercise. The senescent cells in muscle decreased (-48%, P < 0.01) after exercise for 48 h. Low protein supplementation resulted in greater infiltrations of both CD68+ phagocytic macrophage and leukocyte, further decreased p16Ink4a+ senescent cells (-73%, P < 0.001), and delayed increases in regenerative CD163+ macrophage in skeletal muscle, compared with high protein supplemented condition. Significant gain in muscle mass after 12 weeks of training occurred only under high protein supplemented condition. Conclusion: Rapid senescent cell clearance of human skeletal muscle during resistance exercise seems to associate with enhanced in situ phagocytosis. High protein availability accelerates resolution of muscle inflammation and promotes muscle increment after training.