Effective Circuit Training for Aerobics Fitness

The primary functions of circuit training for aerobic conditioning in the fitness centre is to provide a mode of training with sufficient variety to ensure program adherence, to cater for as many people as possible, in as little space as possible, for as little cost as possible. Fortunately, these requirements can be met by an alternative form of circuit training, which is far more effective than the conventional circuits.

Effective aerobic training in a circuit format simply requires longer duration stations with an exercise progression which uses the same muscle groups for as many consecutive stations as possible (given boredom and equipment constraints). Furthermore, when changing the muscle groups used, rather than simply jumping form predominantly lower body to upper body exercises, new muscle groups should be phased in via the use of full body exercises.

The more similar consecutive exercises are the less important the duration of the stations. However, experience has indicated that stations of few minutes seem to provide the best compromise between effective aerobic conditioning and boredom prevention.

An initial problem in running a circuit class or prescribing a circuit program for people used to conventional circuits is that they often tend to go too hard too soon and find it difficult to last the duration of each station. A well designed cardiovascular circuit should in fact feel easier as the length of time spent at each station is increased. A circuit class or program of 20-40 minutes duration, if performed in a continuous manner at even effort, will be most effective if exercisers operate at, or just below, their anaerobic threshold (AnT).

Absolute heart rate levels are of no consequence in determining whether someone is exercising at the appropriate intensity. The appropriate heart rate will vary significantly between individuals (even of the same age and fitness level) and is dependent on the following factors.

1. Their maximum heart rate, which is inversely proportional to heart size (which is dependent on such factors as genetics, body size, age and training background).

2. The percentage of maximum heart rate at which their AnT occurs. This is primarily a function of the total volume of aerobic training undertaken, although it is also influenced by fiber type distribution and is largely exercise specific.

As an individual's AnT increases with training he or she is able to exercise at higher workloads for the same level of perceived exertion and can comfortably maintain a higher heart rate for the duration of an exercise session.

If optimal improvements in aerobic fitness are desired, some higher intensity interval training may be incorporated in the program. For well trained individuals gains in maximal aerobic power are best achieved by including some training where one operates at maximum aerobic power outputs (the lowest exercise intensity required to induce maximum heart rate). The most effective means of performing maximal aerobic power training is to build the exercise intensity slowly over two to three minutes (so as to give aerobic metabolism time to build up and thus minimize the accumulation of lactic acid) to the AnT exercise intensity, and then increase the intensity to a level which stimulates a maximum heart rate response for approximately two minutes.

This form of training is best carried out by people who are already well trained and have relatively high AnT's because only these individuals can operate at maximum heart rate levels for short intervals without extreme discomfort due to high lactate accumulation. MV02 interval training should be only carried out once or twice weekly for optimal results and in order to prevent overtraining.

Such training can be incorporated into a circuit program by performing two to four stations at a higher intensity levels (maximum or near maximum heart rates) and using stations in between for active recovery. This type of interval training is probably best placed near the end of the circuit class or program.

The most appropriate equipment for cardiovascular circuit training is that which effectively works as many large muscle groups as possible and lends itself to aerobic intensity exercise. Equipment which provides visual feedback as to the power output is preferable because this tends to motivate participants. At least some, if not most of the equipment should allow full body exercise particularly when general cardiovascular conditioning and / or weight loss is the goal. Where it is not possible to use full body machines equipment utilizing major lower body muscle groups should be employed.

The employment of specific upper body and abdominal exercises will result in a reduction in total oxygen consumption and energy expenditure, but are of value where specific peripheral aerobic conditioning in those muscles is of prime concern for particular sportspeople.

Conventional cardiovascular training ergometers arc the most effective pieces of equipment to use in aerobic circuits. Equipment such as exercise cycles, steppers and treadmills, will effectively work the large gluteal, quadricep and hamstring muscle groups of the lower body. Bionic cycles and rowing ergometers are excellent full body machines which not only induce the highest oxygen uptake, but also allow effective phasing between muscle groups.

Many non-equipment exercises such as free squatting, shuttle runs, skipping and step-ups can be used, although instructors should be aware that it may be difficult to keep participants motivated for the duration of each station with some of these activities. Instructors should also be aware that activities such as skipping and shuttle runs are very expensive in terms of the space utilized.

Free weights, pin loaded and many hydraulic machines are considerably less effective in achieving cardiovascular training goals as they often do not work a large number of muscle groups and more importantly, they do not lend themselves well to long durations of continuous activity.

A simple, but practical and highly effective circuit might utilize just treadmills, bionic cycles, rowing ergometers, cycles and stepping machines repeated in series as many times as necessary to cater for class numbers.