Author ORCID Identifier

Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation




Kinesiology and Health Promotion

First Advisor

Dr. Mark Abel


Direct current (DC) potential is an objective measure of the functional state of the human organism. It is a sensitive and accurate indicator of short- and long-term adaptations to stress, adaptive capacities, and it is an important marker of athlete readiness. Sleep is posited to be the most efficacious strategy for improving recovery to enhance sport performance, and adequate sleep is considered vital to normal psycho-physiological function. Thus, optimal sleep may enhance the functional state, in turn enhancing an athlete’s adaptability to training stress. However, little is known about the relationship between sleep and DC potential. Therefore, the purpose of this study was to examine the effect of acute (one-night) and extended (two-night) sleep quantity and quality on DC potentials in collegiate American football players. Twenty-four Division 1 American football players (Age: 20.6 ± 1.30 yr; Height: 183.4 ± 6.40 cm; Body mass: 114.40 ± 24.60 kg) wore a wrist-worn actigraphy band seven days per week over the course of 136 days, which spanned the pre-season training camp and competitive season, to measure sleep quantity and quality. DC potential was assessed six days per week using the Omegawave Ltd (Espoo, Finland) athlete monitoring system either 30 minutes upon waking or 75-120 minutes prior to the onset of the football training session. Sleep quantity was stratified into duration categories and sleep quality was stratified within sleep latency, number of awakenings, and sleep efficiency variables. Sleep quantity and quality were evaluated using acute (one night) and extended (rolling average of two consecutive nights) sleep outcomes. Within subject comparisons of DC potential were made across sleep quantity and quality categories using repeated-measures analysis of variance to examine the influence of acute and extended sleep quantity and quality on DC potential outcomes. The level of significance was set at p ≤ 0.025. Statistically significant main effects were identified for acute sleep (F3,16 = 4.68, p < .02, η2p = 0.47) and extended sleep durations (F2,17 = 7.71, p < 0.005, η2p = 0.48). Specifically, for acute sleep durations, there was a 17.1% increase in DC potentials (3.59, p < 0.01, Cohen’s d = 0.52, SE 1.18) for sleep durations ≥ 7 hours to < 9 hours, compared to sleeping < 6. For extended sleep, there was a 20% increase in DC potentials (4.53, p < 0.002, Cohen’s d = 0.68, SE = 1.13) when recording a two-day sleep average of ≥ 7.5 hours and < 9 hours, compared to an extended sleep duration of < 6 hours. A statistically significant main effect was also identified for extended wake episodes (F2,19 = 4.5, p = 0.025, η2p = 0.32). For extended sleep periods with > 4 wake episodes there was a 12% increase in DC potentials (2.57 ± 2.24mV, p < 0.25, Cohen’s d = 0.34) compared to extended sleep periods with 2-3 wake episodes. There was not a significant effect of acute (p ≥ 0.20) sleep quality or extended latency (p > 0.18) and efficiency (p > 0.08) on DC potentials. These findings suggest that sleep quantity affects DC bio-potentials and thus the functional state of the athlete. Specifically, sleep durations between 7.00/7.50 to 9 hours correspond with higher measures of DC potentials compared to lesser durations. Given the effect of sleep quantity on biological markers for training adaptability, practitioners should prioritize sleep in the training process and educate athletes on proper sleep hygiene and sleep quantity to enhance their readiness to train.

Digital Object Identifier (DOI)