Detraining and Ageing Flashcards
What is detraining?
Cessation of exercise training. Detraining may occur due to planned or unplanned reduced volume/intensity.
What did Rasch & Morehouse, 1957 report about strength gains?
Strength gains diminish at a slower rate than which they are gained.
What dictates the loss of strength with cessation of resistance training?
Depends on the inital level of conidtioning
Length of training/detraining period
Subjects involved - older subjects lose strength padidly after 12 weeks of detraining
What is In-season detraining? Is this detrimentsal to performance.
Loss of performance when an individual reduces or cuts out resistance training whilst undertaking other sports specific training.
Athletes in sports with high strength components ca tolerate periods of no resistance training.
What did Staron, Hagerman & Hikida 1981 report about long term detraining with elite powerlifters?
Sevon months detraining and dieting period.
Resulted in a physiological shift from a strength profile to an aerobic profile.
Increase peak oxygn consumption (Vo2 peak). Increased mitochondrial density and oxidative enzyme profile.
NO aerobic training however = reduction in muscle fibre which contributed to decrease in thigh girth.
Other Detraining effects on sporting performance?
24 weeks of heavy RT = 13% increase in vertical jump ability, 12 weeks of Detraining = decrease in vertical jump ability however it was still 2% over baseline.
Bone mineral density decreased after 6 months
Detraining effects in terms of health?
Chronuc detraining = health probelms post career. Obesity and sedentary lifestyle can lead to increased risk of CV disease.
What effect does Detraining have on muscle activity?
4 weeks of Immobilisation =
Biceps brachii and brachioradialis activity reduced by 38% and 29% respectively.
Women displayed a greater reduction of EMG activity compared to men.
What is the impact of immpbilisation on fibre types?
Decline in proportion of type I fibres and an increase in the proportion of type II fibres. This is termed the slow-to-fast hypothesis.
What is the impact of limb unloading on muscle mass and metabolic alterations?
The effect on muscle mass and function is greater in older men whereas metabolic alterations are greater in younger adult men. Older participants had difficulty regaining pre-inactivity conditions.
Limb Suspension Vs. Limb Unloading?
All reduce the mass and strength of muscle.
Limb suspension - preferential effect on slow-twitch muscles, Increase in contractile speed due to changes in fibre type.
Leg Unloading - Impairment of activation, In contrast to suspension, maximal shortening velocity was reduced in type I fibres and increased in type II fibres.
What are the effects of ageing on muscle strength?
-Strength peaks between 20 and 30 years old, then slowly declines until around the age of 50.
After 50yr old, 12% to 15% per decade have eeem reported.
After 65 more rapid losses 30% per decade
What are the ageing effects on muscle power?
Skeletal muscle power has been shown to decline earlier and more rapdily than strength
Significant differences in power revealed between age groups and falls status = relevant measurement of fall risk and function.
What are the effects of ageing on gait?
Propulsive power generation during push-off declines considerably in old age.
What are the effects of ageing on muscle mass? ‘Sarcopenia’
After the age of 25 there is a progressive decrease in size and number of muscle fibres
40% decrease in muscle mass between 25 and 80 years of age.
Loss of preferential type II fibres and frocd per cross-sectional area.
