EXS-401 | Exercise Physiology & Training
Adaptations Master Guide — Principles, Aerobic
Systems, and Overtraining Insights (2025 Edition)
Overload principle - exercise at intensities greater than normal to produce adaptations that enable
the body to function more efficiently
Overload principle requires appropriate manipulation of: - - training frequency
- intensity
- duration
- exercise mode
Specificity principle - refers to adaptations in metabolic and physiologic systems that depend on
the type of overload imposed and muscle mass activated
Individual differences principle - - individuals do not respond identically to an identical training
stimulus
- individuals have different strengths and levels of aerobic capacity at the start of a training
program
- training programs should reflect individual needs and capacities
Reversibility principle - detraining occurs and results in measurable reductions in physiological
function and exercise capacity
Physiological examples of individuals who are confined to bed: - - 1% reduction in aerobic
capacity per day
- decreased capillary density by 15-25%
- decreased VO2max by 25%
- total loss of training improvements occur over several months
Responders vs. non-responders - improvement among individuals completing the same exercise
program is typically variable
Anaerobic system changes - - increase fiber size and function of fast twitch muscle fibers
- increased levels of anaerobic substrates
- increased quantity and activity of enzymes that control glucose metabolism
Adaptations Master Guide — Principles, Aerobic
Systems, and Overtraining Insights (2025 Edition)
Overload principle - exercise at intensities greater than normal to produce adaptations that enable
the body to function more efficiently
Overload principle requires appropriate manipulation of: - - training frequency
- intensity
- duration
- exercise mode
Specificity principle - refers to adaptations in metabolic and physiologic systems that depend on
the type of overload imposed and muscle mass activated
Individual differences principle - - individuals do not respond identically to an identical training
stimulus
- individuals have different strengths and levels of aerobic capacity at the start of a training
program
- training programs should reflect individual needs and capacities
Reversibility principle - detraining occurs and results in measurable reductions in physiological
function and exercise capacity
Physiological examples of individuals who are confined to bed: - - 1% reduction in aerobic
capacity per day
- decreased capillary density by 15-25%
- decreased VO2max by 25%
- total loss of training improvements occur over several months
Responders vs. non-responders - improvement among individuals completing the same exercise
program is typically variable
Anaerobic system changes - - increase fiber size and function of fast twitch muscle fibers
- increased levels of anaerobic substrates
- increased quantity and activity of enzymes that control glucose metabolism
