PepsiCo Global R&D

The results of a prior study PEP-2311 suggested there was a positive dose-response effect of glycerol and sodium on fluid balance and fluid retention. In addition, inclusion of glycerol resulted in an upward shift in the relationship between sodium concentration and fluid balance. The practical interpretation is that addition of glycerol enables a reduction in sodium concentration compared with a 0% glycerol drink.
In this follow-up study, the investigators hypothesize that 1) fluid balance will be sustained (greater than or not different from baseline) and significantly greater than placebo for 120 min after drinking the test no/low/moderate carbohydrate beverages and 2) fluid balance will not differ between the carbohydrate-electrolyte beverages, but both will be greater than placebo.

Sports science testing by investigators at Gatorade Sports Science Institute has revealed that many athletes arrive at practice with a high urine specific gravity indicating they are hypohydrated. Though the data showed that most athletes don't lose more than 2% of their body weight in sweat during a training session, it is not known what the cumulative effects of living and training in a hot environment are over the course of a week. Previous research has indicated that prescribing fluid intake is more effective than education in improving drinking behavior during exercise. No studies to date have compared the impact of fluid intake prescription versus education in adolescent boys and girls playing outdoor and indoor sports.
Comparing sexes and training environment may provide more clarity around potential barriers and challenges to proper hydration for each environment.

Heart rate variability (HRV) is a measure of the variation in time between each heartbeat.
It is an indirect and ubiquitous biomarker of performance readiness and recovery measured by most consumer-grade wearable fitness trackers. However, there is little documented on the relationship between HRV, training load, and performance measures in the Real-World.
Whoop wrist-worn activity trackers have been validated against the gold-standard Electrocardiography (ECG) for HRV and HR measurements. Whoop leverages photoplethysmography (PPG) technology to continuously track (HR, HRV, respiratory rate, energy expenditure) and provides, daily, individual insights, trends, and coaching to improve strain, sleep, and recovery. Research has demonstrated that heart rate variability (HRV) guided training may be more optimal compared to predetermined training for aerobic exercise improvements.
The purpose of this study is to assess the feasibility of providing personalized training recommendations based on HRV measured by a consumer-grade wearable (Whoop) in a real-world setting to better understand the HRV relationship with performance.