A study shows that sleep-deprived runners experience changes in their movement patterns, including reduced cadence and increased ground contact time.

A new study from KU Leuven in Belgium indicates that a lack of sleep significantly alters how individuals move while running. Researchers found that sleep-deprived runners exhibit less leg stiffness before impact, leading to longer ground contact times and a decrease in steps per minute. This research is the first to specifically examine how sleep deprivation influences running biomechanics rather than just physiological factors like heart rate.

Study methodology and findings

The study involved 11 women and 10 men who completed two treadmill runs one week apart. For one session, participants were kept awake, while they followed their normal sleep routine for the other. Researchers used motion-capture cameras and waist-mounted accelerometers to track movement. While running styles differ between individuals, the study found that within a single person, sleep deprivation consistently resulted in taking between one and three fewer steps per minute at the same speed.

Implications for injury risk

The observed changes include increased ground contact time, which is sometimes recommended to reduce joint load. However, experts suggest these biomechanical shifts may contribute to higher injury risks. Maura Seynaeve of KU Leuven noted that the knee appears to be loaded more heavily during these sessions, which could potentially lead to increased knee injuries. Michael Grandner of the University of Arizona College of Medicine supported this, noting that altered movement patterns may be a mechanism for increased injury risk.