The Effect of Total Sleep Time on Ultra-Endurance Triathlon Performance

Abstract

PURPOSE: The primary purpose was to determine the effect of sleep time on performance during a 3-day multistage ultra-endurance triathlon (stage 1: 10km swim, 144.8km bike; stage 2: 275.8 km bike; stage 3: 84.4km run). Secondarily, we determined if performance time predicts sleep time. METHODS: Eighteen triathletes (age: 37±7.9y; height: 175±7cm; weight: 70±9kg) partook in sleep analysis pre, during, and post triathlon using an actigraphy wrist band. Participants wore the band to record sleep time for five days (1-2 days pre-race, 3 race days, 1-day post-race), except during racing. Bands were collected before each stage to download the previous night’s data, then re-distributed after each stage. Performance times were recorded after each stage, and following total completion of the race. The data was analyzed via linear regression. RESULTS: Total sleep time (mean±SD; pre-race: 393.9±81.1 min, pre-stage 1: 342±90.2min, pre-stage 2: 347.5±54.6min, pre-stage 3: 299.7±107.0min, post-race: 308.8±86.3min) significantly decreased over time (P<0.05). Sleep time predicted performance in multiple stages. Specifically, pre-stage 3 sleep time explained 30% and 43% of the variation in stage 3 performance (R2=0.30, p=0.035), and total finishing time (R2=0.43, p=0.008). Performance time also predicted sleep time. Specifically, stage 1 performance explained 37% and 47% of the variation in pre-stage 2 sleep time (R2=0.37, p=0.010), and pre-stage 3 sleep time (R2=0.47, p=0.005). Stage 2 performance explained 39% the variation in pre-stage 3 sleep time (R2=0.39, p=0.014). Total race sleep time (Pre-stage 1, 2, and 3) was averaged; 33% of the variation in total finishing time can be predicted by average total racing sleep time (R2=0.33, p=0.015). No additional relationships were seen. A cutoff value was found at 401.6 min of average total race-night sleep time, indicating the top 25% of race finishers slept for ≥401.6 min. CONCLUSIONS: During a multistage ultra-endurance triathlon, performance time can be predicted by sleep time the night before. In addition, faster performance times during each stage predicts more sleep time. Based on our results, average total race-night sleep time of roughly 402 min (6.7h/night) leads to faster finishing time in the Ultraman Florida. This study was supported by FSU and FatigueScience.