One Night of Acute Sleep Deprivation Alters Running Biomechanics and Running Economy in Recreational Runners.

PURPOSE: This study examined the effects of one night of sleep deprivation on lower-limb biomechanics and running economy while running at different intensities.

METHODS

Sixteen healthy recreational runners (7 male, 9 female) completed a randomized crossover study comparing one night of total sleep deprivation (SDEP) with normal sleep (CON). In each condition, participants completed submaximal treadmill running at intensities corresponding to 90% LT1, LT1, and 90% LT2, followed by a fourth interval to exhaustion at LT2. Spatiotemporal, kinematic, and kinetic data were collected using an instrumented treadmill and 3D motion capture, while metabolic rate was assessed via indirect calorimetry.

RESULTS

Sleep-deprived subjects were running with a lower cadence (p=.030), longer ground contact time (p<0.001), and higher duty factor (p=0.012). Peak vertical ground reaction force and loading rate were reduced in SDEP (p=0.002 and p=0.011). Knee flexion angle and peak knee extensor moment during the stance phase were larger in SDEP (p=0.015 and p=0.037). Average positive knee power increased in SDEP (p=0.019), while average positive ankle power decreased in SDEP (p =0.019). SDEP also led to a decrease in leg stiffness (p=0.028). Gross metabolic power was significantly reduced in SDEP compared to CON, suggesting improved running economy (p<0.001). Time to exhaustion during the last running interval was reduced by 13.2% in SDEP compared to CON (p=0.023).

CONCLUSIONS

Sleep deprivation increased duty factor, shifted joint contributions from distal to proximal muscles and reduced leg stiffness while also reducing gross metabolic power at a given speed. Despite these efficiency gains, participants fatigued more quickly at their second lactate threshold.