Sleep plays a crucial role in how accurately you can judge your Reps in Reserve (RIR), which is the number of repetitions you believe you can still perform before reaching failure during an exercise set. When you get enough quality sleep, your brain functions better, improving your ability to assess your physical limits accurately.
Lack of sleep impairs cognitive functions such as reaction time, attention, and decision-making. These cognitive declines can make it harder to gauge how many reps you have left in a set, leading to either stopping too early or pushing too far, which can increase injury risk or reduce training effectiveness. Studies show that after even one night of poor sleep, reaction times slow and accuracy in tasks requiring focus drops significantly[3]. This cognitive fatigue translates into less precise self-monitoring during workouts.
Moreover, good sleep enhances physical performance aspects like speed, coordination, and muscle control, which are essential for maintaining proper form and effort during reps. Research on athletes indicates that sleeping between 7 to 10 hours improves sprint times, reaction speed, and shooting accuracy, suggesting that sleep quality directly influences physical precision and control[1]. This improved physical control helps you better sense your exertion levels and thus estimate your RIR more accurately.
On the other hand, poor sleep quality, such as that caused by evening exposure to smartphones, reduces total sleep time and sleep efficiency, leading to increased daytime sleepiness and decreased physical performance[2]. This sleep disruption can blunt your ability to judge effort and fatigue during training, making your RIR estimates less reliable.
In summary, sufficient and high-quality sleep supports both the mental clarity and physical readiness needed to accurately assess your Reps in Reserve. Without it, your judgment of how many reps you can perform safely and effectively becomes less precise, potentially impacting your training outcomes.
Sources
https://sportsxlab.com/de/sleepcyclesperformancesandinjuryinathlete/
https://www.theupside.us/p/upside-studies-1-soccer-study-evening
https://www.psychiatrypodcast.com/psychiatry-psychotherapy-podcast/episode-251-combatting-the-negative-effects-of-sleep-deprivation
