Pretraining Characteristics and Exercise Adherence
Tables - present the mean ± SDs pre- and posttraining values for the metabolic syndrome parameters, body composition, cardiorespiratory fitness, physical activity, and basal metabolic rate by treatment condition. There were no significant differences among the three conditions at baseline for any outcome measure (all p > 0.1; Tables -). presents the summary data for exercise adherence, volume, and intensity. Both the LIET and HIET groups had similar exercise adherence, with ~79 ± 3% and ~83 ± 3% of the assigned exercise sessions completed within each exercise condition, respectively. We did not observe a differential rate in dropouts among the three conditions (). During LIET exercise sessions the mean RPE was ~ 11; for HIET, the mean RPE was ~15 during the HIET sessions and ~12 during the LIET sessions. By design, the mean velocity per session and the mean RPE per session were significantly higher in the HIET group during their HIET days compared to the LIET group. There were no statistically significant differences between the two training groups for the total estimated caloric energy expenditure.
The effects of 16-weeks of either no exercise training (Control, n = 7), low-intensity exercise training (LIET, n = 11), or high-intensity exercise training (HIET, n = 9)on the parameters associated with the metabolic syndrome.
Table 3 The effects of exercise training intensity on various cardiometabolic risk factors in obese women with the metabolic syndrome following 16 weeks of either no exercise training (Control, n = 7), light-intensity exercise training (LIET, n = 11), or high-intensity (more ...)
Mean (SEM)[median] exercise data by treatment group.
Metabolic Syndrome Parameters
By design, all participants had elevated waist circumference and at least two of the following; elevated fasting blood glucose, low HDL-C, hypertriglyceridemia, and were normotensive to mildly hypertensive at baseline (). HIET significantly reduced waist circumference (p = 0.001), which was significantly greater than the reductions observed in response to Control and LIET (p = 0.039 and p = 0.035, respectively; ) after adjusting for the baseline values. LIET significantly reduced systolic blood pressure (p = 0.002), which was significantly greater than the reduction observed in response to Control (p = 0.023; ) after adjusting for the baseline values. However, the remaining metabolic syndrome parameters remained unchanged.
HIET significantly reduced total abdominal fat (p < 0.001, ), AVF (p = 0.010; and ) and abdominal subcutaneous fat (p = 0.034; and ) after adjusting for the baseline values. There were no significant changes observed in any of these parameters within the Control or LIET conditions. The reductions in total abdominal fat and abdominal subcutaneous fat cross-sectional areas in the HIET condition were significantly greater than those observed in the LIET condition (p = 0.017 and p = 0.033, respectively) after adjusting for the baseline values. Although the reduction in AVF within HIET condition (-24 cm2) was much greater than that observed within Control condition (-2 cm2) and the LIET condition (-7 cm2) these differences did not reach the level of statistical significance across conditions (p = 0.098 and p = 0.153, respectively). HIET also significantly reduced total mid-thigh fat (p = 0.001; and ). We did not observe a significant change in total mid-thigh skeletal muscle among the three treatment conditions (p > 0.1; and ). HIET significantly reduced total body weight (p = 0.013), BMI (p = 0.009), and fat mass (p = 0.011) ().
The effects of 16-weeks of either no exercise training (Control, n = 7), low-intensity exercise training (LIET, n = 11), or high-intensity exercise training (HIET, n = 9) on measures of body composition in obese women with the metabolic syndrome.
Figure 2 Effects 16 weeks of no exercise training (Control, n = 7), low-intensity exercise training (LIET, n = 11), and high-intensity exercise training (HIET, n = 9) on abdominal subcutaneous abdominal fat (B), visceral fat (A), total mid-thigh skeletal muscle (more ...)
LIET and HIET significantly elevated VO2 Peak (p = 0.047, p = 0.004, respectively; ). The increase in VO2 Peak in the HIET condition exceeded that for Control and LIET conditions (p = 0.016, p = 0.078, respectively; ). VO2 LT was unchanged after training in all three conditions (all p > 0.1; ). LIET and HIET resulted in significant elevations in peak treadmill velocity (p = 0.006, p < 0.001, respectively; ). HIET induced a greater elevation in peak treadmill velocity than Control and LIET (p = 0.005, p = 0.056, respectively; ).
BMR, Physical Activity and Diet
We did not observe any significant changes in the BMR () or substrate oxidation assessed using the basal respiratory exchange ratio (data not shown). We also did not observe any significant changes in total physical activity in response to the three treatment conditions (). A limitation of the present study is that due to incomplete dietary data we were unable to adequately analyze the dietary records for pre- to posttraining changes in caloric intake.
Spearman Correlation Analyses
Pooled Spearman correlation analyses (N = 27) were conducted to examine the relationships among pre- to posttraining changes weight, percent fat, AVF, and the metabolic syndrome parameters. Weight loss was positively associated with reductions in triglycerides (r = 0.56; p = 0.002) and SBP (r = 0.44; p = 0.022). Fat mass loss was also positively associated with (r = 0.49; p = 0.009) triglycerides.