Types of Muscle Action

1. Types of Muscle Action • Static (isometric) • Dynamic • isotonic • concentric • eccentric • set resistance • variable resistance • isokinetic

2. Static • No movement • No cost • Travels well

3. Static • A major disadvantage is that strength gains are specific to the joint angle used during training.

4. Dynamic • Isotonic resistance training involves concentric and eccentric contractions of the muscle group performed against a constant or variable resistance. • Free weights • Nautilus

5. Dynamic • Isokinetic resistance training • Accommodating resistance • Speed controlled • Cybex

6. Isokinetic Training • Isokinetic training involves dynamic, shortening contractions of a muscle group against an accommodating resistance that matches the force produced by the muscle group throughout the entire range of motion.

7. Isokinetic Training • Isokinetic training is done at speeds that vary between 24 and 300 degrees per second depending on the needs of the individual.

8. Comparison • All of the resistance training methods are effective for developing strength and muscle endurance.

9. Comparison • Dynamic training is preferable to static training (isometric) because dynamic training develops greater strength and muscular endurance.

10. Comparison • Motivation is generally superior with dynamic training, because the individual receives visual feedback concerning the amount of weight lifted, and can set explicit goals.

11. Comparison • Static exercise can effectively counteract strength loss and muscular atrophy when a body part is temporarily immobilized due to injury.

12. Comparison • Static exercise is also especially useful when circumstances do not allow the use of dynamic exercise (e.g., limited space and equipment).

13. Comparison • Isokinetic exercise combines the advantages of dynamic (full range of motion) and static (maximum force exerted) exercise.

14. Comparison • Since the resistance is accommodating, isokinetic training overcomes the weakness of using either a constant or variable resistance exercise mode.

15. Comparison • In addition, isokinetic training as fast speeds apparently produces strength gains not only at the training velocity but also at speeds slower than the training velocity.

16. Comparison • Isokinetic training is not the best choice, however, when the goal of training is an increase in muscle size.

17. Eccentric Muscle Action • Eccentric contractions apparently are essential for muscle hypertrophy.

18. Muscular Fitness • Muscular strength and endurance are developed through the overload principle - by increasing resistance to movement or the frequency or duration of activity to levels above those normally experienced.

19. Muscular Fitness Continuum

20. Muscular Fitness • Muscular strength is best developed by using weights that develop maximal or nearly maximal muscle tension with relatively few repetitions

21. Muscular Fitness • Muscular endurance is best developed by using lighter weights with a greater number of repetitions.

22. Improvement Muscle strength and endurance gains will be determined by: • Training • Nutrition • Genetics • Hormone secretion

23. Specificity • The development of muscular fitness is specific to the muscle group that is exercised, the type of contraction, and the training intensity.

24. Specificity • Strength and endurance gains are also specific to the speed and range of motion used during training.

25. Overload • To promote strength and endurance gains, the muscle group must be exercised at work loads that are greater than normal for the client.

26. Intensity • Intensity is inversely related to the number of repetitions.

27. Intensity • A set consists of a given number of consecutive repetitions of the exercise.

28. Training Volume • Training volume is the total amount of weight lifted during the workout and is calculated by summing the products of the weight lifted, repetitions, and sets for each exercise.

29. Intensity • Intensity is expressed either as a percentage of the individual’s 1-RM or as the maximum weight that can be lifted for a given number of repetitions of an exercise (e.g., 8-RM equals the maximum weight that can be lifted for 8 repetitions).

30. Muscular Strength Intensity • In most cases, the exercise intensity should be at least 60% of maximum to stimulate the development of strength.

31. Muscular Strength Intensity • More rapid strength gains may be achieved, however, by exercising the muscle at or near maximum (80 to 100%) resistance. • Optimal health and fitness

32. Muscular Strength Intensity • At this intensity, most individuals are able to perform 6 to 8 repetitions (6 to 8 RM) of the exercise.

33. Intensity • The intensity of resistance training can be manipulated by varying the weight, the number of repetitions, the length of the rest interval between exercises, or the number of sets of exercises completed.

34. Determining Maximum • There are several ways of determining someone’s maximal capacity. • The direct technique is to measure 1-RM for each exercise you would include in someone’s program

35. Determining Maximum • 1-RM Testing (Kraemer & Fry, 1995) • 1. Have your client warm-up by completing 5 to 10 reps of the exercise at 40% to 60% of the estimated 1-RM • During a 1-min rest, have the client stretch the muscle group. This is followed by 3-5 reps of the exercise at 60%-80% of the estimated 1-RM

36. Determining Maximum • 3. Increase the weight conservatively, and have the client attempt the 1-RM lift. If the lift is successful, the client should rest 3-5 mins before attempting the next weight increment. Follow this procedure until the client fails to complete the lift. The 1-RM typically is achieved within 3-5 trials.

37. Determining Maximum • 4. Record the 1-RM value as the maximum weight lifted for the last successful trial. • Risk of injury associated with 1-RM testing in adults is 2.4%

38. Determining Maximum • Indirect techniques (estimates) include basing maximum on • Start with 45% of body mass

39. Determining Maximum • Prediction equations (p 128 Heyward) are based on the numbers of reps (<10) to fatigue in one set • Men (Brzycki, 1993): • 1-RM = wt lifted (lb)/[1.0278-(reps* 0.0278)] Example • 1-RM = 100lb/[1.0278-(7 reps*0.0278)] • = 120 lbs

40. Determining Maximum • Middle-aged women (40-50) • 1-RM = (1.06*wt in Kg)+(0.58*reps)-(0.2*age)-3.41 • Older women (60-70) • 1RM = (0.92 * Wt lifted in Kg) + (0.79*reps) – 3.73 • [Kuramoto and Payne, 1995]

41. Progression • You must periodically increase the training volume (how much work you do).

42. Progression • Progression needs to be gradual, because doing too much too soon may cause musculoskeletal injuries and excessive muscle soreness.

43. Progression • The number of repetitions a client is able to perform will indicate when the resistance needs to be increased throughout the training program.

44. Progression • The rate of improvement slows, and eventually plateaus, as clients progress through the program and move closer to their genetic ceiling.

45. Sets • Although improvements in muscular fitness may result from performing only one set of a given exercise, research suggests that multiple sets (3 or more) are more beneficial for optimal gains in muscular fitness.

46. Frequency • Improvements in muscular fitness may result from exercising just one day per week, especially for clients with below-average muscular fitness.

47. Frequency • However, research suggests that exercising 3 times per week improves both the rate and amount of strength gain.

48. Variations of Frequency • Most exercise specialists advocate a split routine, in which different muscle groups are targeted on consecutive days, in order to allow at least one day of recovery for each muscle group.

49. Variations of Training Volume • To prevent overtraining and to optimize strength and power gains for peak performance, many athletes who train year-round divide their resistance training program into cycles.

50. Variations of Training Volume • This method is known as periodization.