Progressive Resistance Training (PRT) 
Progressive Resistance Training is an effective intervention for improving physical functioning in older people, including improving strength and the performance of some simple and complex activities.
It involves incrementally increasing load (weight) during resistance exercise across a program period of 6, 8 or 12 weeks.
Individuals are asked to number their rate of perceived exertion (RPE) between 6 (no exertion) to 20 (maximal exertion). Each number represents a heart rate value such as 6 being 60 bpm which is the average resting heart rate and 20 being 200bpm which is the average maximum one can reach.
PRT programs can be designed and implemented under Exercise Physiology supervision.