Strength Training

Effects of Strength Training Hypertrophy Hyperplasia?? Decreased body fat %, increased LBM Does NOT increase VO2max Circuit training can provide MILD increase May increase LT during cycling

Possible Neural Factors of Strength Gains w Recruitment of additional motor units for greater force production w Counteraction of autogenic inhibition allowing greater force production w Reduction of coactivation of agonist and antagonist muscles w Changes in the discharge rates of motor units w Changes in the neuromuscular junction

MODEL OF NEURAL AND HYPERTROPHIC FACTORS

Selecting the Appropriate Resistance Strength—few reps and high resistance (6-RM) Muscular endurance—many reps and low resistance (20-RM) Power—several sets of few reps and moderate resistance; emphasize speed of movement Muscle size—more than 3 sets of 6-RM to 12-RM loads; short rest periods

Resistance Training Actions Static (isometric) actions Dynamic actions w Free weights w Eccentric training w Variable resistance w Isokinetic actions w Plyometrics Electrical stimulation training

ACSM Recommendations for Resistance Training Perform exercises for all major muscle groups (8 -10 exercises) Minimum of 1 set of 8-12 repetitions to the point of volitional fatigue 10-15 reps may be appropriate for elderly Perform exercises 2-3 d/wk Adhere to proper technique Perform exercises through full ROM

ACSM Recommendations (cont.) Perform concentric and eccentric contractions in a controlled manner Maintain a normal breathing pattern (avoid Valsalva Maneuver) If possible, exercise w/ a training partner

Periodization w Changes in exercise stimulus over a specific period to keep an individual from overtraining w Cycle of five phases: four active phases followed by one active recovery phase w Each phase gradually decreases volume and gradually increases intensity

Varied Multiple Set Program 3 days per week 1 strength day- 5 repetitions 1 endurance day- 15 repetitions 1 hypertrophy day- 10 repetitions Less boredom

Acute Muscle Soreness w Results from an accumulation of the end products of exercise in the muscles w Usually disappears within minutes or hours after exercise

Delayed-Onset Muscle Soreness (DOMS) w Results primarily from eccentric action w Is associated with damage or injury within muscle w May be caused by inflammatory reaction inside damaged muscles w May be due to edema (accumulation of fluid) inside muscle compartment w Is felt 12 to 48 hours after a strenuous bout of exercise

Sequence of Events in DOMS 1. Structural damage 2. Tissue edema and inflammation 3. Increased cell tension and strain from edema and agents (prostaglandins and histamine) cause pain. 4. Additional muscle tissue breakdown and pain due to formation of proteases, phospholipases, and oxygen radicals. 5. Cells repair themselves and form protective proteins that prevent muscle soreness during subsequent workouts.

Gender Differences in Strength Females have less absolute strength 50% less upper body 30% less lower body Little or no difference in relative strength (strength per cross-sectional area of muscle)

MEN’S vs WOMEN’S STRENGTH

ST FIBER DISTRIBUTION

Neuromuscular Adaptations in Women w Women's magnitude of strength gained from resistance training is similar to men's. w Women generally don't gain as much muscle size as men do from resistance training. w Less muscle mass is a result of lower testosterone levels.