Final answer:
For muscle strength and mass, the ACSM recommends 6-12 reps per set with appropriate resistance, and for muscular endurance, a lower resistance with 15-25 reps. Resistance training stimulates hypertrophy, and progressive overload is essential for continued muscle growth and increased strength.
Step-by-step explanation:
To develop muscle strength and muscle mass, the American College of Sports Medicine (ACSM 2018) recommends selecting a resistance that allows the individual to complete 6 to 12 repetitions per set. For improving muscular endurance, a lower resistance (<50% 1-RM) and 15 to 25 reps are recommended. Exercise activities like resistance training promote muscle fiber hypertrophy
. As the muscle fibers, specifically the fast glycolytic (FG) fibers, are exposed to resistance, they experience micro-tears that, through proper rest and nutrition, heal and become thicker, leading to an increase in overall muscle size known as hypertrophy.
Muscles adapt to the increased load through resistance training, necessitating the progressive addition of more weight to challenge the muscle and stimulate further growth and strength gains. Connective tissue development also plays a significant role in accommodating the growing muscle mass and strength.