The Importance of Rest Days For Runners

Updated: 29/01/2026

As athletes, it’s incredibly easy to fall into the trap of thinking that progress only happens when we’re running further or faster. In reality, this mindset is one of the quickest routes to your physio’s treatment table. Progress in running isn’t just built by training harder. It’s built by training smarter, and rest is a non-negotiable part of that equation.

Progressive overload refers to the gradual increase of a training variable in order to continually challenge the body and force adaptation. For runners, this usually means slowly increasing weekly mileage, increasing intensity or paces, or adding more demanding sessions over time.

This process is essential for improvement, but continuous increases without interruption are not safe. Your body needs time to repair, replenish, and adapt to the stress you place on it. When progressive overload is paired with adequate rest, the body can actually absorb the training and become stronger, faster, and more resilient. Without rest, overload simply becomes overload.

Rest days are when training stress is converted into meaningful adaptation. Running places cumulative load on muscles, bones, connective tissue, the nervous system, and hormonal balance, and while training provides the stimulus for change, rest is what allows these systems to recover, recalibrate, and become more resilient.

Physically, rest supports muscle repair while also giving slower-adapting tissues such as tendons, ligaments, and bone time to strengthen, which is critical for reducing overuse injury risk. At the same time, recovery restores nervous system function, improving coordination, efficiency, and perceived effort so running feels smoother rather than forced. Rest also allows stress hormones to normalise, energy stores to be replenished, inflammation to resolve, and immune function to recover, creating an internal environment where training adaptations can actually occur. Mentally, stepping back from structured training reduces psychological fatigue, helps maintain motivation, and supports long-term consistency.

In short, rest doesn’t interrupt progress. It makes progress possible.

When recovery is repeatedly delayed or ignored, training stress accumulates faster than the body can adapt, shifting running from a stimulus for improvement to a source of breakdown. Over time, this imbalance can quietly undermine your body and mind, leaving you more vulnerable to injuries, chronic fatigue, and long-term setbacks.

Consistently under-recovering can lead to a wide range of issues, including:

• Overuse injuries affecting bone, muscle, or connective tissue

• Persistent fatigue and declining performance

• RED-S (Relative Energy Deficiency in Sport), particularly when combined with inadequate fuelling

• Hormonal disruptions

• Poor sleep quality and disrupted sleep patterns

Planned recovery interrupts this cycle before it becomes a problem. By deliberately scheduling rest, runners allow adaptation to occur while maintaining training consistency, reducing the likelihood of injury-driven, unplanned breaks. In this sense, rest days are not lost training time but a strategy for protecting future training.

Recovery does not always require complete inactivity. Low-impact, low-intensity movement such as swimming, cycling, walking, or gentle yoga can promote circulation and recovery without adding meaningful stress, while intentionally slowing down reinforces the purpose of the day. Importantly, rest days should still be fuelled appropriately, as the energy demands of repair and adaptation often match, or exceed, those of training days.

Rest days are not a sign of weakness or lost motivation. They are a strategic tool that allows training to work. If you want consistency, longevity, and real progress in running, rest isn’t optional. It’s part of the plan.