Reading Personal Trainer:
During the early stages of fitness training, especially with entry level athletes, any strength training will give some improvements in strength development. As the athlete builds a better strength foundation a new program should be developed to maximise the athlete’s natural abilities. Every person is different and will adapt differently in response to exercise.
The beginning stage of fitness is called the anatomical adaptation phase to adapt the muscles to cope with heavier loads during the later stages of training. Load training should be increased without too much discomfort to the athlete.
Circuit training can be used to develop the foundations of strength training before starting the other training phases.
Circuit training includes body weight exercises, medicine balls, light weights and any other strength training machine. A short circuit may include 6-9 exercises, medium 9-12, or long 12-15 exercises and can be repeated several times depending on the number of exercises included. When deciding the number of stations, repetitions, and the load the athlete must consider their fitness level. Total workout during the anatomical adaptation phase should not cause discomfort .
Circuit training is useful for building the foundations of strength, however it is not the only approach. Circuit training should alternate muscle groups, which facilitates recovery. The rest intervals between stations can be anywhere between 60-90 seconds, with 1-3 minutes between circuits. Variety is important with circuit training and easy to implement.
Circuit training is used by most military forces to build muscular endurance in athletes. However other forms of training are also conducted in order to build muscular strength, speed and power (depending on the military force).
I personally know a Hungarian champion pro boxer who only ever did circuit training and boxing training to get to his professional level. This is perhaps not the norm as most athletes will include weight sessions to improve muscular strength and if the athlete needs to bulk up then muscular hypertrophy will be included prior to a muscular strength stage.
If in doubt as how to progress your training then visit the training phases article which explains the different stages of training and the principles behind them.