The objective of this study was to determine how a high-intensity circuit-training (HICT) program affects key physiological health markers in sedentary obese men. Eight obese (body fat percentage >26%) males completed a four-week HICT program, consisting of three 30-minute exercise sessions per week, for a total of 6 hours of exercise. Participants' heart rate (HR), blood pressure (BP), rating of perceived exertion, total work (TW), and time to completion were measured each exercise session, body composition was measured before and after HICT, and fasting blood samples were measured before throughout, and after HICT program. Blood sample measurements included total cholesterol, triacylglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, glucose, and insulin. Data were analyzed by paired t-tests and one-way ANOVA with repeated measures. Statistical significance was set to P < 0.05. Data analyses revealed significant (P < 0.05) improvements in resting HR (16% decrease), systolic BP (5.5% decrease), TW (50.7%), fat tissue percentage (3.6%), lean muscle tissue percentage (2%), cholesterol (13%), triacylglycerol (37%), and insulin (18%) levels from before to after HICT program. Overall, sedentary obese males experienced a significant improvement in biochemical, physical, and body composition characteristics from a HICT program that was only 6 hours of the total exercise.
Alex’s Notes: Circuit-training is hard. Well, it can be if you are giving it your all. It is a combination of resistance training and endurance work that incorporates both multi-joint resistance training and callisthenic exercises that keeps the heart rate elevated for the duration of the training session. There are many health benefits of both resistance training and endurance training that are independent of one another, and thus circuit training may be a method of achieving the best of both in a short amount of time. This study aimed to see if a short-duration circuit training program would improve cardiovascular responses, body composition, blood profile, and physical performance in eight healthy but obese individuals.
The program was 4-weeks long with training sessions 3x/week. It wasn’t a push-over routine either, with participants completing 3 sets of 8-12 reps in the squat, bench press, partial-curl-up, dead-lift, burpee, bent-over row, and shoulder press in a circuit fashion. As for results, performance definitely improved as the total weight lifted increased by over 50% from the first to the last session. Resting heart rate, blood pressure, body-fat, total cholesterol and other biochemical markers also significantly decreased.
Granted the study was on obese individuals, but given how efficacy has become key in exercise programming and a “lack of time” is the most quoted deterrent for participating in an exercise program, short duration high-intensity exercise (circuit training) may come to the forefront as the exercise prescription of choice for those who are at risk of chronic disease.