Weight Training Programs
Strength gains initially start slowly as the body accommodates to the stimulus and program, then accelerate rapidly, and then they slow down and level off. The weaker the initial strength, the greater the percentage of improvements
Weight training has been associated with reduced mitochondrial density in the muscle cell, increased concentrations of creatine phosphate, ATP, and glycogen, and increased lean body mass and muscle cross sectional area.
Hypertrophy of muscle is perhaps the most obvious result of weight training. Transient hypertrophy occurs during, and for several hours after, exercise. It is the result of accumulation of fluid in the interstitial and intracellular spaces of the muscle. The more permanent hypertrophy can be a result of four factors:
- Increase in the number and size of myofibrils per muscle fiber
- Increases in the amounts of contractile proteins (actin and myosin)
- Increase in capillary density per muscle fiber (more as a result of endurance training)
- Increased amounts of connective, tendinous and ligamentous tissues
Strength and cross sectional area of muscle fibers are strongly associated with each other. The larger the muscle fiber the greater the number of actin myosin filaments, therefore a greater number of cross bridges are possible to produce muscular force during contractions. The cross section of a limb does not correlate as strongly with strength because the limb is composed of fat, bones, skin, connective tissues, and blood. Factors that influence the amount of hypertrophy from training are:
- Individual differences in adaptations to training
- Genetic potential of the individual
- Amount of nutritious food consumed
- The severity and duration of the overload imposed
With resistance training, selective hypertrophy of fast-twitch muscles results in an increase in the fast-twitch to slow-twitch ratio of fiber area. The rapid increase in strength during the initial stages of weight training programs is not due to increased muscle, but to changes in the nervous system. Learning facilitates the increase in strength. In addition, after one becomes accustomed to resistance training, reduced apprehension and psychological inhibition also account for strength increases. The neurological components in strength acquisition include
- Increases in motor unit synchronizations
- Inhibition of co‑contraction of antagonists
- Increased activation of prime movers
- More precise and efficient modes of motor unit recruitment
The improved neural functioning and coordination are the most prominent factors in strength increases during the initial 3 to 5 weeks of resistance training. Strength depends on the ability of the nervous system to appropriately activate the muscles and this can be improved quickly.
Using a Weight Training Log
Demonstration and Description of Exercises
General Principles for
Common Training Mistakes
Weight Training Adaptations
Benefits of Weight Training
Voluntary Muscular Activity
The General Adaptation
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