Resistance Training Flashcards
Skeletal muscle
- considered plastic in response to training and detraining
-
Fibres are classified due to ?
speed of contraction and characteristics
Max hypertrophy must work
- at 80-95% recruiting all fibres in this range
- relative intensity vs 1rm: to maximise strength must go to fatigue
Sarcomeres
- removed when shortened (hypotrophy)
- added when lengthened (hypertrophy)
strength improvements are very rapid
Time course of adaptations to training
- Early increases are neural (skill, reduced inhibition and improved synchronisation).
- However, there is still a good correlation between x-sectional area and strength (especially in a heterogenous population).
- Early changes in strength are paralleled by changes in EMG; later changes in strength are not matched by changes in EMG (and are therefore attributed to ‘myogenic’ changes)
Myogenic
structural changes
- improvements in strength and force with training
Neural adaptations
- to strength training can involve recruitment of high threshold motor units not previously recruitable and an increased firing rate of motor units.
- only for new trainers who haven’t exercised before
Retraining
- will retain strength more quickly then the first time
can increase force with training but no change in what?
EMG
Agonist muscles
- make a greater contribution to movement after strength training and reduce co-contraction of antagonist
Co-contraction of the antagonist
- provides joint stability
- improves movement coordination
- most common in high velocity moments where precision and braking are required
Body builders
- don’t need to be measured on strength
- tend to do high reps, endurance sessions
- more type 1 fibres than type 2
- differs from weightlifters and powerlifters
Hypertrophy
- grow in size
Hyperplasia
- enlargement of an organ or tissue caused by an increase in the reproduction rate of its cells, often as an initial stage in the development of cancer.
To increase muscle fibres must …
split existing muscle fibres
Resistance training can
- reduce total cholesterol by 2.7%
- reduce LDL by 4.6%
- reduce TG by 6.4%
- increase HDL by 1.4%
endurance training impairs or betters strength training
impairs
Reasons for this interference
- Fatigue that reduces the quality of the training and impairs the rate of adaptation.
- Related to this is the problem of energy depletion - this will also reduce the quality of the second session if energy and fluid replacement is not met post-exercise.
- Fibre types -> endurance training will lead to adaptations to type I fibres and an increase in mitochondrial density.
- Mitochondria may occupy the space which would otherwise be taken up by contractile proteins (body builders vs power lifters).
Upper body strength decreases with endurance running could be because
- the release of catabolic hormones in response to a fall in blood glucose during endurance work; non-active muscle proteins may be catabolised for gluconeogenesis
lot of endurance work
- drop of blood glucose - release of cortisol (breaks down protein into amino acids which go to liver) and glucagon - potentially catabolic stripping away muscle
endurance fitness
- important for athletes who engage in high intensity intermittent training due to time or recovery of creatine phosphate and removal of lactic acid
eccentric exercise
- A persons ability to complete an eccentric- isometric-concentric contraction is limited by the force production in the concentric phase.
- contracting but in a lengthening situation
- if unaccostomed can result in loss f strength, reduction of ROM, muscle soreness, elevated plasma CK activity and limb
Delayed onset of muscle soreness (DOMS)
- tearing in sarcomeres and can take some time to resolve (can get swelling, sore to touch - can get blood test to measure by creatine kinase, if high it means muscle damaged)
muscles repair themselves stronger so will prevent DOMS occurring again - occurs 12-48 hours after exercise
- mostly eccentric muscle action
- soreness can be improtant part of maximising resistance training response
- if repeat same exercise 6 weeks later will not cause same amount of damage
periodization of cyclic training
- Change in training volume (decrease) and intensity (increase) over the course of the year/season
- Rest or reduced training periods / provides variety
Resistance training for normal aging
- increased adiposity
- reduced muscle mass (sarcopenia)
- reduced strength
- reduced aerobic capacity
- reduced BMD
Dietary insufficency
- low protein diets have been shown to lead to a loss in muscle mass and function
- protein intakes of at least 1g/kg of body weight per day may be more appropriate
Plyometric training
muscles exert max force in short intervals of time - to increase power
- jumping (harvest elastic energy)
Hormonal decline
- decrease growth hormone
- decrease testosterone and estrogen
Effect of training
- max force can exert resistance training
- important in remaining independent?
Sarcopenia consequences
- decrease BMR - decrease 15% between 3rd and 8th decades
- decrease bone mineral density
- decrease aerobic capacity
- decrease functional capacity - walking, stair climbing
Normal vs Osteoporotic bone
- decrease in the amount of bone
- deterioation in bone structure
Benefits of exercise for older adults
- increase muscle mass and strength
- increase cardiorespiratory fitness
- steadiness of bone mass/BMD (modest effect 1-3%)
- increase spontaneous physical activity
- increase dynamic balance
- increase gait speed, stair-climbing power
- decrease body fat
- decrease chronic diseases
- decrease all-cause mortality
