How Often Should You Strength Train?
A practical explanation of strength-training frequency for adults.
Public-health guidance includes muscle-strengthening work on at least two days per week for adults. That is a population-level baseline rather than an individualized prescription.
Program design changes the answer
Training history, exercise selection, effort, volume and recovery all affect sensible frequency.
Also see rest days.
Health note: Exercise needs vary. If you have a chronic condition, disability, injury, or concerns about starting exercise, seek appropriate professional guidance.