- Intensity of work
e.g., 100% maximum muscle strength is possible for a maximum of 6 seconds, 75% at 21 secs, 50% at 60 secs, 25% at 3.5 mins, 15% at >4 mins
- Repetition of the work
- Muscle size (small muscles fatigue quicker)
- Boredom (reduces concentration & increases fatigue)
- Fitness (Flexibility, strength and stamina)
- Duration and Frequency
