Discussion
±, nutritional beverage, MCAs
ADVERSE EFFECTS
The purpose of this investigation was to examine the effectiveness of three different beverages (CHO, CHO-P, and PLA) on short-term recovery from repeated bouts of exhaustive exercise in male endurance MCAs. The results support our hypothesis that CHO-P (0.8 g/kg bm CHO + 0.4 g/kg bm PRO) was equivalent to CHO (1.2 g/kg bm) for promoting an increase in time to exhaustion (TTE) performance following a 2-hour recovery period. Both CHO and CHO-P were superior to PLA (electrolytes and water) for supporting short-term recovery in masters class endurance athletes. The other main finding of this investigation was that both CHO and CHO-P appeared to be equally effective and significantly better than PLA in promoting HRR as assessed via the HRRi.A similar study with younger participants [On an individual level, unadjusted values indicated 63% (5 of 8) of participants in the PLA group demonstrated a decline in TTE performance averaging a − 68 sec change from the first to second bout of exercise, with a range of −16 to −185 sec. In comparison, only one of seven participants in the CHO group experienced a decrease in TTE performance (−18-sec) during the subsequent exercise bout, with the range of The MCAs who completed this study identified with a specific sport (i.e. primarily cycling but also running), and while as a group cannot be considered professional road cyclists, time-trial and exercise capacity testing are considered valid performance measurements for endurance athletes who regularly engage in prolonged high-intensity exercise that require periods of sustained power output [Three previously published studies that have examined post-exercise isocaloric CHO (1.2 g/kg bm) and CHO-P (0.8 g/kg bm CHO + 0.4 g/kg PRO) drinks and recovery from exhaustive exercise in young endurance-trained males have demonstrated that glycogen resynthesis postexercise is not necessarily the primary determinant of endurance-based performance outcomes [TTE at 90% PPO, while significantly improved during a subsequent bout of exercise relative to PLA, was not different between the CHO and CHO-P groups. CHO-P was not superior to CHO for improving acute TTE performance during a subsequent bout of high-intensity exercise; however, the addition of protein to a recovery beverage may have longer-term benefits. Doering et al. (2016) reported that a group of masters triathletes consumed 0.3 ± 0.2 g/kg bm of protein in the post-exercise recovery meal, which is slightly less than the recommended amount of 0.4 g/kg bm that has been found to maximally stimulate muscle protein synthesis in older adults [We found that adding protein to the recovery drink did not interfere with the acute performance benefits also seen in the CHO group. The inclusion of protein in the recovery drink has additional benefits, such as creating a more anabolic environment. As a result, athletes may be able to adjust more quickly to changes in their training schedules when they add protein to their diet. In support, Churchward-Venne et al. (2020) reported that whole-body net protein balance was The current investigation utilized a novel index to examine HRR relative to total work. Results indicated an improved recovery for both the CHO and CHO-P conditions at each of the three time points postexercise, with no difference between conditions. In comparison, the PLA condition was inadequate for promoting HRR at 1-, 2-, and 5-min postexercise as evidenced by a significantly higher HRRi value. The findings of an improved recovery for the CHO and CHO-P conditions are similar to the findings of Moreno and colleagues (2013) and others [Even though in the current study PLA provided similar amounts of water and electrolytes, it is possible that HRR may not be a suitable indicator for assessing recovery of parasympathetic activity either with fluid alone (i.e. water), within the first 5 min of exercise cessation, or following high-intensity exercise [There are several limitations to this study, including the rate of compliance completing the electronic 24-hour dietary assessment. In addition, dietary intake was not standardized among participants prior to the experimental protocol; however, statistical analysis revealed no significant differences in energy intake or macronutrient distribution between the three treatment groups for those athletes that did comply. We did not standardize dietary intake on the day of the experimental protocol nor was the high-intensity exercise examined in a fasted state. We also did not quantify or restrict caffeine intake 24 hours prior to testing. The goal of this investigation was to examine recovery from high-intensity exercise in an applied manner which allowed for exercise testing without a drastic change to the participant’s habitual diet or nutritional pre-exercise practice [This is the first study to examine the effect of an isocaloric CHO vs CHO-P drink on performance during a repeated bout of exhaustive exercise following a 2-hour recovery period in MCAs. The primary novel outcome of this study was that CHO-P was equally effective as CHO for enhancing performance in a subsequent bout of high-intensity exercise with a limited time to recover. In addition, the incorporation of a novel index to examine HRR relative to total work (HRRi) indicated an improved recovery for both the CHO-P and CHO conditions within the first 5 min of exercise cessation, in comparison to a water and electrolyte solution. This study found that the use of an adequate CHO-containing nutritional beverage significantly improved recovery in the group of masters class endurance athletes, while replacing a portion of the carbohydrate content with protein had no adverse effects on either recovery or performance.