CHAPTER 10 RESISTANCE TRAINING: PROGRAMMING AND PROGRESSIONS | ACE PERSONAL TRAINER MANUAL MUSCULAR STRENGTH/POWER/ENDURANCE RELATIONSHIPS
MUSCULAR STRENGTH IS THE FOUNDATION OF ALL PHYSICAL ACTIVITIES. Every movement humans make requires a certain percentage of maximal muscular strength. The standard measure of muscular strength is the highest resistance that can be moved through the full movement range at a controlled movement speed, which is referred to as the one-repetition maximum (1-RM). Muscular endurance is closely related to muscular strength, and is typically assessed by the number of repetitions that can be performed with a given submaximal resistance. Most people can complete approximately 10 repetitions with 75% of their 1-RM weightload. For example, if a client’s maximal bench press is 100 pounds (45 kg), he or she can probably perform 10 repetitions with 75 pounds (34 kg) (75% of the 1-RM). If training increases this client’s 1-RM bench press to 120 pounds (54 kg), he or she can most likely complete 10 repetitions with 90 pounds (41 kg) (75% of the new 1-RM). That is, this client’s “relative muscular endurance” maintains the same ratio to his or her maximal strength. However, when the client’s 1-RM bench press increases to 120 pounds (54 kg), he or she can perform approximately 15 repetitions with 75 pounds (34 kg), because this weightload is now only 62.5% of his or her maximal strength. Therefore, this client’s “absolute muscular endurance” increases as muscular strength increases. Muscular power is the product of muscular strength and movement speed. Assuming that an individual’s movement speed remains the same, an increase in muscular strength is accompanied by a proportional increase in muscular power. However, the relationship between the exercise weightload and muscular power is somewhat complex, and is best represented by an inverted U curve (Figure 10-2). Training with light resistance enables fast movement speed, but results in a relatively low power output due to the low strength component. Training with heavy resistance enables a high strength component, but requires slow movement speed, and therefore results in a relatively low power output. Training with medium resistance and moderate-to-fast movement speeds produces the highest power output and is the most effective means for increasing muscular power.
Figure 10-2 The relationship between the exercise weightload and muscular power
Low strength High Power Low Resistance Component
TRAINING VARIABLES: FACTORS AFFECTING STRENGTH DEVELOPMENT AND PROGRAM DESIGN
THERE ARE SEVERAL EXERCISE PERFORMANCE FACTORS THAT AFFECT THE RATE and degree of strength development. These training variables include volume, intensity, tempo, rest intervals, and frequency.
