Training age is the number of years an athlete has been training consistently. It predicts the rate of adaptation: beginners (0-2 years) respond rapidly to almost any stimulus; intermediates (2-5 years) need periodisation and progressive overload; advanced athletes (5+ years) require highly specific programming to make marginal gains. Training age also determines appropriate programme complexity — beginners should not use advanced programmes designed for experienced athletes. Training age resets partially after extended layoffs.
- 0-2 years = beginner (fastest gains)
- 2-5 years = intermediate
- 5+ years = advanced (marginal gains)
- Programme complexity should match training age