The benefits of Circuit Training
Circuit training has long been used to improve strength and fitness. It was first formally studied and refined by R.E. Morgan and G.T. Anderson in 1953 at the Universityof Leeds1 but had been a staple of military training for far longer.
The core objectives of circuit training are to increase muscle strength, endurance, flexibility and coordination. Studies at BaylorUniversityand The Cooper Institute have suggested that circuit training is the most time efficient way in which to improve cardiovascular fitness and muscular endurance2.
Whilst boxing clubs, the armed forces and more traditional gyms have maintained use of circuits, popularity has waned in recent years. However, due to the multiple fitness benefits it provides it is now beginning to enjoy a renaissance, with many clubs now offering circuit classes of varying intensities
What does it involve?
The term circuit training does not refer to one particular exercise; instead it describes a series of exercises performed in a consecutive manner3. A "circuit" refers to one completion of the exercises within a set programme, usually including a combination of both aerobic exercise and strength (resistance) training. A good circuit training course works the different sections in the body individually, ensuring that no two consecutive exercises work the same muscle group.
The training is built around ‘stations’ or exercises performed in a certain order, with a minimal rest in between (sometimes as short as how long it takes to cross from one station to the next or to swap equipment). These stations can last from 30 seconds to several minutes depending on the demands of the exercise, if any resistance is used, and the fitness of the participants.
Effective aerobic and simple resistance exercises you can choose from include star jumps, jogging or running on the spot, skipping ropes, squat-thrusts, push-ups, crunches, using a treadmill or other cardiovascular exercise machines. When one circuit is complete, you simply begin the first exercise again for another circuit. A total of 1-3 circuits are typical, with 2-3 minutes rest between each circuit4. 3-4 brief sessions per week are an effective way to develop all-round fitness.
What are the benefits?
Circuit training is a flexible workout, in that you can choose which exercises to include and the combination that best helps you to accomplish your exercise goals.
The most motivating circuit sessions involve small groups within a gym environment, allowing beginners to be guided by more experienced individuals, as well as benefiting from the supervision of the instructor. However, it can also be performed in isolation and in very limited spaces.
The circuit science bit
There are several established physiological responses to circuit training:
- Greater cardiovascular endurance
When performed consistently over 8-12 weeks, circuit training can increase aerobic oxygen consumption and VO2 max, resulting in greater stamina and overall fitness 5. - Increased muscular endurance and strength
Resistance training overloads muscles for improved endurance and strength. Strength training is particularly important for women, who lose muscle mass of 1% per year in their 30s and 40s, along with those aged 65 to help minimize bone loss. - Significant caloric expenditure
The amount of calories burned per workout depends on its intensity and duration, the exercises selected and the exerciser’s body weight. Circuit training has been reported to burn approximately 500-600 kcal/ hour 7 (depending on body weight) however, this number increases significantly when exercisers also perform aerobic intervals. During circuit training, heart rates fluctuate between aerobic and anaerobic zones, demanding more calories than either a traditional steady-state cardio or strength session alone. - Improved body composition and higher metabolism
Research demonstrates that circuit training decreases fat mass 6, and strength training increases lean body mass, which is more metabolically active than fat. Routine strength training builds muscles that burn more calories both during exercise and at rest (basal metabolic rate) for a higher metabolism, which helps with fat loss and weight management.
So can anybody do it?
A common misconception is that circuit training is only for fit people. However, circuit training can be tailored to suit everybody. I point out to my clients who are concerned that they will not be able to complete a session that nobody can make the stations any harder for them or will keep score of the reps they do. If you leave a circuit class knowing you couldn’t have worked any harder, no more can be asked of you.
As you get fitter, the number of reps you can do in a given time will increase. You can also progress by decreasing the rest intervals between stations. As a result, circuits can be demanding no matter what your fitness level.
Conclusion
Circuit training is an excellent way to develop and maintain fitness with limited time, space and or equipment. Used by many professional athletes to maintain off-season fitness and prepare for the rigours of pre season training, it also offers the fitness enthusiast a powerful and varied tool to change body composition and develop many areas of fitness. All of my clients who undertake my circuit classes demonstrate increased balance, core strength and stability and muscular endurance during their PT sessions. So why not try circuit training for just a month to keep your workouts fresh and your body challenged; you may find yourself getting fitter whilst spending less time in the gym.
About the author
Anthony Brett BSc PGCE (PE) Cert Dip (Clinical Nutrition) is an experienced trainer, nutritionist and NLP Practitioner. He runs his own training company Pro Edge Nutrition Strength and Conditioning in Liverpool and is based at The Gym Group Liverpool 1.
www.ProEdgeNSC.com
07796 598 857
Anthony@proedgensc.com
References:
1. Kraviz, L., (1996). New insights into circuit training. Universityof New Mexico. Retrieved from: http://www.unm.edu/~lkravitz/Article%20folder/circuits05.html
2. Robert D Chetlin, Resistance Training - Contemporary Issues in Resistance Training: What Works? Fit Society, AmericanCollegeofSports Medicine, September 2002.
3. Scholich M. (1992) Circuit Training for All Sports.Toronto: Sports Books Publishers.
4. Fleck SJ and Kraemer WJ. (2004) Designing Resistance Training Programs: 3rd Edition.Champaign,IL: Human Kinetics.
5. Osterberg, K. L. & Melby, C. L., 2000. Effect of acute resistance exercise on post exercise oxygen consumption and resting metabolic rate in young women. International Journal of Sport Nutrition and Exercise Metabolism, 10 (1), 71-81.
6. Gettman, Larry R. and Michael L. Pollock (1981). Circuit weight training: A critical review of its physiological benefits. The Physician and Sports medicine, 9: 44-60.
7.Nutristrategy (2011). Calories burned during exercise. Retrieved from: http://www.nutristrategy.com/activitylist.htm
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