Effects of Exercise on Muscles

(immobilization or denervation) Muscle inactivity (immobilization or denervation) results in muscle weakness and wasting (atrophy)

Regular exercise leads to increased muscle size, strength, and endurance. Results of increased muscle use Increase in muscle size Increase in muscle strength Increase in muscle efficiency (muscle becomes more fatigue resistant)

Different types of exercise leads to different muscular results

Aerobic or Endurance Training more flexible muscle more fatigue resistance muscles increased blood supply muscle cells form more mitochondria muscle cells store more oxygen muscles do not increase in size

Resistance, Weight, or Isometric training individual muscle cells enlarge cells make more contractile filaments the amount of connective tissue that reinforces the muscle also increases

WHERE DO WE GET ENERGY FOR EXERCISE?? Brief power exercise (6 seconds) rely on breakdown of ATP stored in muscles If high energy is needed for up to 60 seconds, anaerobic respiration continues with production of lactic acid If intensity diminishes and time extends 2 – 4 minutes, aerobic respiration (ATP production) increases to 99% of needed energy

WHY DO ATHLETES TRAIN?? To stimulate structural and functional adaptations that will improve specific tasks.

TRAINING PROGRAMS SHOULD FOCUS ON: frequency of workout length of workout type of training speed intensity duration of exercise repetition of activity rest intervals

PRINCIPLES: OVERLOAD: Increase intensity greater than normal by increasing frequency, intensity, and duration of exercise. SPECIFICITY: specific training for specific results. Anaerobic (weights training) results in strength and power adaptations Endurance exercises increase cardiovascular fitness (as well as only muscles exercised in the specific task) You must overload the muscles used in the specific sport in order to see the gains in training Little improvements shown with dissimilar exercise, significant improvements shown with exercise similar to the sport.

WHAT CAUSES SPECIFICITY?? Training improvements are most beneficial due to the improved aerobic fitness of the specific muscles used in a specific sport! Muscles specific to the sport have a greater aerobic capacity – higher endurance because these muscles can generate more ATP aerobically, there is less lactic acid build up due to less % anaerobic respiration. This increase in aerobic capacity is due to a greater regional blood flow because of increased microcirculation and changed cardiac distribution of blood flow. An example is how the vastus lateralis has a greater aerobic capacity on bicyclists than distance runners!

INDIVIDUAL DIFFERENCES: Different people will respond differently to training stimulus Starting fitness is a factor Same intensity but maybe at different cardiovascular stress levels (heart rate may vary) High levels of conditioning can be lost by all during times of inactivity