The Effects of Pre-Loaded Betaine Supplementation on Thermoregulation and Exercise Metabolism in the Heat

This will be a double blind, placebo-controlled, randomized, counterbalanced, crossover study designed to assess the impact of preloaded betaine supplementation on thermoregulation and exercise metabolism in the heat. The study, outlined in Figure 7 and described in detail below, will consist of seven total visits to the Institute of Sports Science and Medicine (ISSM) or Sandels laboratories at Florida State University, two of which will be experimental visits. On the first visit, participants will be informed as to the details of the study before giving their oral and written informed consent (Appendix A). Thereafter, anthropometrics will be measured and participants will complete an incremental exercise test on an electronically-braked cycle ergometer to volitional exhaustion to determine peak oxygen consumption (VO2 peak). Days 1-6 participants will consume a full dosage of supplementation, whereas day 0 and 7 participants will consume half a dose of the supplement, with the last dosage being consumed 60 minutes prior to experimental visits, days 7 and 21. On days 2 and 4, familiarization trials will be completed to standardize training loads and to reduce any potential learning effect. These visits will be implemented in the heat. On day 7, participants will complete the first experimental trial described in detail below. Afterwards, participants will enter a seven day washout period 167 before crossing over to the second supplemental condition on day 14. On days 16 and 18, participants will undergo the same familiarization trials as they did on days 2 and 4. On day 21, participants will complete their second experimental trial. Each experimental trial will be separated by 14 days. This study will be approved by the Florida State University Insitutional Review Board (Appendix B).