Understanding your result
How it's estimated
Each session type has a baseline recovery window (e.g. legs and powerlifting ~72 h, moderate cardio ~24 h). We then adjust for how hard you trained, your sleep, age and nutrition — the factors that most affect how fast muscle repairs.
Recovery = base hours × intensity × sleep × age factor
⚕️ A general training guide, not medical advice. Persistent pain, swelling or a sharp injury needs rest and, if it continues, a clinician. Listen to your body over any calculator.
Questions
How long should muscles rest between workouts?
Typically 48–72 hours for a trained muscle group after hard resistance work; lighter or cardio sessions recover faster. Poor sleep and higher age extend it.
Can I train the same muscle daily?
Generally not at high intensity — muscles grow during recovery. Alternate muscle groups or intensities to train more often.
Sources
Evidence-based · last reviewed July 2026