Elsevier

Nutrition

Volume 53, September 2018, Pages 34-37
Nutrition

Applied nutritional investigation
Protein supplementation enhances cerebral oxygenation during exercise in elite basketball players

https://doi.org/10.1016/j.nut.2018.01.015Get rights and content

Highlights

  • High-protein supplementation accelerates fatigue recovery in cycling performance.

  • High-protein supplementation enhances cerebral oxygen saturation during cycling.

  • Enhanced cerebral oxygen saturation relieves cerebral blood demand during cycling.

  • Increased peak insulin is associated with improved exercise hemodynamic response.

Abstract

Objective

The 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.

Methods

This was a randomized, counterbalanced crossover study. Fifteen Division 1 collegiate basketball players (18–20 y) consumed 6.25 kcal/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.

Results

Before 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 (P < 0.01) and attenuated increases in cerebral blood perfusion (total hemoglobin; P < 0.01) during the cycloergometer exercise; and resulted in a 16% longer cycling time (from 474 ± 49 s to 553 ± 78 s, P < 0.05), compared with the low-protein trial.

Conclusion

Enhanced 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.

Introduction

Carbohydrate has long been considered the most important fuel for maximizing sports performance based on the fact that a low-carbohydrate diet may limit glucose supply to both muscle and the central nervous system [1]. Because protein cannot be used to support anaerobic metabolism in fast-contracting muscles, it is thought to be a less-relevant substrate to support high-intensity exercise. This viewpoint has been revised by several studies consistently showing an enhanced performance when a minor fraction of carbohydrate is replaced by protein in an isocaloric supplement consumed after a fatiguing challenge [2], [3], [4]. These data demonstrate that the role of protein supplementation on accelerated fatigue recovery is less likely related to substrate supply for energy production in fast-contracting muscle [5].

Brain is the supreme commander of muscle fiber recruitment [6] and a critical determinant of muscle performance [7]. Beneficial effects of whey protein supplementation on brain function have been suggested by several studies. In animals, improved brain mitochondria functions with suppressed free radical levels by whey protein supplementation suggest its action on brain oxygen efficiency [8]. In humans, improved brain function by consumption of major components of whey protein also has been found in antenatal stress and perinatal brain injury models [9]. In a double-blind, placebo-controlled study, intake of whey protein–enriched diet significantly alters mental function measures among patients [10]. Taken together with the evidence of decreased blood pressure and increased flow-mediated vascular dilation in hypertensive adults [11], the present study hypothesized that whey protein consumption may improve brain hemodynamic regulation against physical stress.

Recent findings on cerebral oxygenation during exercise at different ambient oxygen concentrations have demonstrated that cerebral oxygenation is a limiting factor for high-intensity performance [5]. To our knowledge, scientific report regarding brain hemodynamic response during exercise after whey protein supplementation is rarely available. The aim of the present study was to determine whether changing whey protein content in carbohydrate-based supplementation influences cerebral hemodynamic response against high-intensity exercise in elite basketball players, when the supplement was consumed during a 2-h recovery after a 1-h exercise challenge. Cerebral hemodynamic response to exercise and aerobic fitness have been reported to be associated with insulin and glucose levels [12]. Therefore, insulin and glucose responses after the protein supplementation also were measured during the recovery before the cycling performance test.

Section snippets

Ethics, consent, and permission

The present study was approved by the institutional review board at the University of Taipei. This study initially recruited 16 young Division 1 (top 8 in the nation) collegiate basketball players. During the experiment, one player was dropped out. The remaining 15 participants were 18 to 20 y of age, with an average weight of 78.4 ± 10.8 kg, height of 182.2 ± 7.1 cm, and body mass index (BMI) of 23.5 ± 0.5 kg/m2. All participants provided voluntary written informed consent after receiving an

Results

To assess the effect of protein supplementation on fatigue recovery, basketball players were challenged by a 1-h cycling at 70% VO2max and recovered at rest for 2 h. Protein supplement was orally delivered in liquid form immediately after exercise. Blood glucose was assessed every 30 min during recovery before cycling performance time trial. Fasting glucose (Fig. 1A) and insulin (Fig. 1B) concentrations did not differ between either trial. After protein supplementation, it was found that

Discussion

Previous studies have demonstrated that incorporating more protein in carbohydrate-based supplementation enhances fatigue recovery, as assessed by endurance performance [2], [3], [4]. Results of the present study confirmed the ergogenic benefit of protein supplementation on endurance performance to a similar extent when it was supplemented during a relatively short recovery time after exercise [4]. The key finding of the present study is that increasing protein content in a carbohydrate-based

Conclusion

The current data confirmed findings from previous studies that increasing protein ratio in carbohydrate-based supplement for exercised individuals enhanced fatigue recovery in high-intensity endurance performance. The present study further provided new evidence to suggest that the improved fatigue recovery in high-endurance performance is associated with increased cerebral oxygenation and less blood demand to the frontal brain, suggesting an oxygen-sparing effect. Increased peak insulin with

References (17)

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This work was supported by Beijing Competitor PROC; University of Taipei, Taiwan; Ministry of Science and Technology, Taiwan. The sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. CYC and CHK contributed equally to this study. KCH, YJ, BW, and CFH designed the study. KCH, HYW, YYW, CY, and KWT collected and analyzed the data. KCH, YJ, BW, and CFH were responsible for data interpretation and manuscript preparation. All authors approved the final version of the paper. The authors have no conflicts of interest to declare.

1

CYC ([email protected]) and CHK ([email protected]) contributed equally to this work.

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