Effects of Three Commercially Available Sports Drinks on Substrate Metabolism and Subsequent Endurance Performance in a Postprandial State

Abstract

Purpose: To examine the effects of commercially available sports beverages with various components on substrate metabolism and subsequent performance. Methods: Two studies were conducted in a double-blinded, counterbalanced manner. Study I was designed to determine the glycemic index, while study II determined the utilization of substrates and subsequent exercise performance. Ten healthy male participants (age 21.70 ± 2.41 years, height 176.60 ± 5.23 cm, weight 66.58 ± 5.38 kg, V̇O2max 48.1 ± 8.4 mL/kg/min) participated in both study I and study II. Three types of commercially available sports beverage powders were used. The powders consisted primarily of oligosaccharides (low molecular weight carbohydrates, L-CHO), hydrolyzed starch (high molecular weight CHO, H-CHO), and whey protein powder with carbohydrate (CHO-PRO). They were dissolved in purified water with identical CHO concentration of 8% (w/v). In study I, each participant underwent two oral glucose tolerance tests (OGTT) and one glycemic response test for each sports drink. In study II, participants cycled for 60 min at 70% V̇O2max, one hour after consuming a standardized breakfast. One of four prescribed beverages (L-CHO, H-CHO, CHO-PRO, and Placebo control, PLA) was served at 0, 15, 30, 45 min during the exercise. Six hours after the first exercise session, participants came back for a “time to exhaustion test” (TTE). Blood samples were drawn at 0, 30, and 60 min in the first exercise session, while arterial blood gas analysis was conducted at 0, 30, and 60 min in both sessions. Subjective feelings (rating of perceived exertion and abdominal discomfort) were also evaluated every 30 min during exercise. Results: Compared to the reference standardized glucose solution, the glycemic index of the L-CHO beverage was 117.70 ± 14.25, while H-CHO was 105.50 ± 12.82, and CHO-PRO was 67.23 ± 5.88. During the exercise test, the insulin level at 30 and 60 min was significantly lower than baseline following the treatment of L-CHO, H-CHO, and PLA (p < 0.05). The CHO oxidation rate at 60 min in the first exercise session was significantly higher than that at 60 min in the second exercise session following the L-CHO treatment (p < 0.05). Time to exhaustion was not significantly different (p > 0.05). Conclusion: The CHO sports beverage with additional PRO maintains insulin production during endurance cycling at 70% V̇O2max in the postprandial state. L-CHO sports beverage suppresses fat utilization during the subsequent exercise performance test. The subsequent exercise performance (as evaluated by TTE) was not influenced by the type of CHO or the addition of PRO in the commercially available sports beverages used in the present study.

Non-Alcoholic Beverages, Old and Novel, and Their Potential Effects on Human Health, with a Focus on Hydration and Cardiometabolic Health

“…While sport drinks necessity continues to be debated, it does appear that they do make an impact on recovery, especially in terms of glucose levels. In another study evaluating the effects of commercially available sports drinks on substrate metabolism and subsequent endurance performance in a postprandial state, the carbohydrate sports beverage with additional protein was shown to maintain insulin production during endurance cycling at 70% O 2 max in the postprandial state [ 71 ]. This is an interesting finding because if we consider intake of such a beverage in a non-exercise regime then the induction of insulin secretion may plausibly over time contribute to insulin resistance.…”

“…This is an interesting finding because if we consider intake of such a beverage in a non-exercise regime then the induction of insulin secretion may plausibly over time contribute to insulin resistance. Additionally, one needs to consider the amount of simple carbohydrate typically found in those drinks (which is considerable) and how that can contribute to significant simple sugar intake raising significant concerns associated with simple sugar intake discussed earlier [ 71 ].…”

Post-exercise Glucose Response Following Whey Protein Ingestion in Healthy Young People: A Randomized Pilot Study

“…In healthy humans receiving whey protein before and during a 120 minute cycling challenge, blood glucose was reduced compared to those who consumed alanine and placebo [17]. Qin et al [33] provided participants with a whey protein carbohydrate combination drink during a long exercise session. Following the exercise bout, they found a smaller AUC for blood glucose with the whey protein condition, but it was not significant.…”

The Effect of Ingesting Carbohydrate and Proteins on Athletic Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

“…Some studies [15,18] did not include a preceding exercise bout to deplete muscle glycogen levels, while others [10,11,13,14,16,17] did include a depletion ride. Furthermore, the majority of trials have investigated the effect of carbohydrates and proteins (CHO-PRO) when recovery time is limited [11,13,14,19,20]. Under these circumstances it may not be possible to restore substrate losses and promote muscle damage repair [2].…”