Introduction:
Excess body fat and abdominal obesity have been associated with cardiovascular diseases. While aerobic exercise is often recommended to prevent fat accumulation, less evidence exists detailing the specific effects of resistance exercise, independent of or combined with aerobic exercise, on the development of excess body fat and abdominal obesity.
Hypothesis:
We hypothesized that resistance exercise would be associated with a lower incidence of developing excess body fat and abdominal obesity.
Methods:
Participants were 7,685 men and women aged 18 to 89 years (mean age, 46) who received a preventive medical examination during 1987-2005 in the Aerobics Center Longitudinal Study. Participants with a history of myocardial infarction, stroke, cancer, excess body fat, or abdominal obesity at baseline were excluded. Resistance exercise (RE) and meeting the 2008 US Physical Activity Guidelines (RE ≥2 days/week) for RE were determined by self-reported leisure-time exercise. Excess body fat was defined as % body fat (≥25 in men, ≥30 in women) based on underwater weighing or skinfold measurements and abdominal obesity as waist girth (>102 cm in men, >88 cm in women). Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident excess body fat and abdominal obesity by RE levels after adjusting for baseline age, sex, examination year, body weight, current smoking, heavy alcohol drinking, and meeting aerobic exercise (AE) guidelines (≥500 MET-minutes per week).
Results:
During an average follow-up of 5 years, 1517 (20%) developed excess body fat and 552 (14%) developed abdominal obesity. Individuals meeting the RE guidelines (30%; 2323 of 7685) had a 26% and 25% lower risk of developing excess body fat (HR: 0.74; 95% CI: 0.65 to 0.84) and abdominal obesity (HR: 0.75; 95% CI: 0.61 to 0.92), respectively, after adjusting for potential confounders including AE. The HRs (95% CIs) of incident abdominal obesity were 0.70 (0.48-1.01), 0.62 (0.44-0.87), 0.98 (0.67-1.42), and 0.62 (0.42-0.91), while the HRs (95% CIs) of incident excess body fat were 0.84 (0.69-1.03), 0.71 (0.59-0.86), 0.75 (0.59-0.96), and 0.56 (0.43-0.72), in weekly RE time of 1-59, 60-119, 120-179, and ≥180 minutes/week, respectively, compared with no RE. In the combined analysis of RE and AE, HRs (95% CIs) of incident excess body fat and abdominal obesity were 0.71 (0.53-0.95) and 0.62 (0.37-1.04) in meeting RE guidelines only, 0.86 (0.77-0.97) and 0.80 (0.66-0.97) in meeting AE guidelines only, and 0.65 (0.56-0.75) and 0.62 (0.49-0.79) in meeting both RE and AE guidelines, respectively, compared with meeting none of the guidelines.
Conclusions:
We found that RE, independent of and combined with AE, is associated with a reduced risk of developing excess body fat and abdominal obesity.
Region-specific effects of isoflurane anesthesia on Fos immunoreactivity in response to intravenous cocaine challenge in rats with a history of repeated cocaine administration
