Strong evidence

Acute sleep loss measurably impairs physical performance.

In practice

A bad night doesn't mean skipping the session — it means expecting less from it. Keep the movements, drop a set, don't chase a personal best, and rate the effort honestly so next week's targets aren't set off a bad day.

What it doesn't say

Effects vary by task and by how much sleep was lost. This is about acute loss, not the long-term consequences of chronic short sleep.

Source

• Craven J, McCartney D, Desbrow B, Sabapathy S, Bellinger P, Roberts L, Irwin C (2022). Effects of acute sleep loss on physical performance: a systematic and meta-analytical review. Sports Medicine, 52:2669–2690. doi.org/10.1007/s40279-022-01706-y