Muscle Fitness program
The combination of strength and endurance results in muscular endurance - the ability to perform many repetitions against a given resistance for a prolonged period of time (1).
It is a crucial element of fitness for athletes such as distance runners, swimmers, cyclists and rowers. It's also important for success in many team sports like soccer, field hockey and Australian rules football.
Traditionally, muscular endurance programs have used moderate loads lifted for 12-25 repetitions. However, this is completely inadequate for many sports such as boxing, canoeing, distance running, cycling, swimming, rowing, x-country skiing, triathlon and many others.
Any form of training must mirror the specific demands of the sport. In resistance training, this means that the load used should match the resistance that must be overcome while competing. The number of repetitions or the duration of exercise bouts in a session should approach that during the event.
Recall that muscular endurance training makes up only one part of the annual strength program - even for endurance athletes. It should follow a phase of maximal strength training. This makes sense because the greater an athlete's maximal strength, the greater their potential for strength endurance - i.e. the more force they will be able to apply over a prolonged period. Heavy strength training has also been shown to improve exercise economy in endurance athletes (3, 4, 5). For more information on the the annual strength program see the the sport specific approach to strength training programs.
Different sports require different levels of muscular endurance. While each program will vary according to the athlete's needs, muscular endurance can be split into 3 groups:
Athletes like baseball pitchers, sprinters, 50-m freestyle swimmers, martial artists, wrestlers, fencers, tennis players and so on must produce powerful movements and repeat them several times with little or no rest. In order to maintain the same amount of power with each effort, a certain level of power endurance is required.