134 Calisthenics
Increasing the number of repetitions per set develops endurance. For example, if an
individual can perform only 10-12 sit-ups using proper technique, the exercise will develop
muscle strength. Once an individual can perform over 15 repetitions per set, muscle
endurance is being developed. Table 8-1 outlines the strength-endurance continuum and
illustrates the training schedules used to develop various degrees of endurance. Note that
strength and short-term efforts have no effect on aerobic capacity because the aerobic/
endurance system is not recruited with maximal or heavy loads. In contrast, sustained
efforts with a light load recruit the aerobic system and have minimal effect on strength.
Generally, activities of longer duration require more muscle endurance. SEALs should
modify their training programs according to the principles of strength and endurance
specific to mission requirements.
*RM = Repetitions Maximum Effort
Modified from Sharkey, BJ: Physiology of Fitness, 3rd Ed. Champaign, IL: Human Kinetics, 1990, p 91.
In general, calisthenics develop muscle endurance. There are two occasions,
however, when calisthenics develop muscle strength. The first occasion depends on
individual fitness level and how many repetitions can be performed. Individuals who can
only perform a low number of repetitions of a calisthenic exercise (less than 10-12) will
develop muscle strength. Those who can perform a higher number (more than 10-12) will
develop muscle endurance. For example, when you first start doing pull-ups you may only
be able to perform 9 repetitions. At this point, you are developing muscle strength. As your
performance improves, and you are able to perform over 12 repetitions, you begin to
develop muscle endurance.
Table 8-1. The Strength-Endurance Continuum
STRENGTH
SHORT-TERM
EFFORT
INTERMEDIATE
EFFORT
SUSTAINED
EFFORT
Goal
Maximum
force
3 sets
3 times/week
Endurance with
heavy load
3 sets
3 times/week
Endurance with
intermediate load
2 sets
3 times/week
Endurance with
light load
1 set
3 times/week
Recommendation 6-10 RM* 6 - 12 RM 12-50 RM Over 100 RM
Enhances
Strength
Muscle
contractile
proteins: actin
and myosin;
connective
tissue
Some strength;
anaerobic
metabolism
Some aerobic and
anaerobic
metabolism; slight
strength
improvement
Aerobic
enzymes; fat
utilization
Does Not Alter CapacityAerobic CapacityAerobic Strength
