The effect of a short-term high-intensity circuit training program on work capacity, body composition, and blood profiles in sedentary obese men: a pilot study

Abstract

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.

Figure 1

Measurements of exercise intensity. (a) The total work completed (primary y-axis) and the working heart rate (secondary y-axis). Significant (P < 0.05) differences between the first exercise session and exercise sessions 8–12 are indicated by an *. (b) Rate of perceived exertion for each exercise session throughout the HICT program. All data represent means ± SD.

Figure 2

Heart rate and blood pressure measurements. (a) Resting heart rate for each participant measured prior to each exercise session. Significant (P < 0.05) differences between the first exercise session and exercise sessions 10–12 are indicated by an *. Differences between before and after HICT program for (b) resting HR, (c) systolic BP, and (d) diastolic BP. Significant (P < 0.05) differences are indicated by an * and all data represent means ± SD.

Figure 3

Body composition measurements. Differences between before and after HICT for (a) body mass index, (b) body fat percentage, (c) percentage of body fat tissue, (d) percentage of lean tissue, and (e) percent of fat found in the arm, leg, and trunk. Significant (P < 0.05) differences are indicated by an * and all data represent means ± SD.