What we know about detraining:

https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Rightwards arrow" aria-label="Emoji: Rightwards arrow">Strength can be maintained for 3-4 weeks before decline

https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Rightwards arrow" aria-label="Emoji: Rightwards arrow">Muscles start to atrophy after 2-3 weeks

https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Rightwards arrow" aria-label="Emoji: Rightwards arrow">Endurance decreases by 4-25% after 3-4 weeks

https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Rightwards arrow" aria-label="Emoji: Rightwards arrow">VO2 max declines by 6-20% at around 4 weeks

- To maintain strength & hypertrophy during 4+ weeks off, train once per week.

- To maintain endurance during 4+ weeks off, you can lower volume by 60-90% and frequency by 20-30%. Intensity should remain the same.

Sources:

- McMaster et. al, 2013
- Costa et. al, 2016
- McMahon et. al, 2014
- Fisher et. al, 2013
- Mujika et. al, 2001
- Mujika et. al, 2000