OBJECTIVE: The dose-response effects of exercise training on insulin sensitivity, metabolic risk, and quality of life were examined. METHODS: Sixty-one healthy, sedentary (VO2max 35 +/- 5 ml/kg/min), moderately overweight (BMI 27.9 +/- 1.8), young (age 29 +/- 6 years) men were randomized to sedentary living (sedentary control group; n = 18), moderate (moderate dose training group (MOD): 300 kcal/day, n = 21), or high (high dose training group (HIGH): 600 kcal/day, n = 22) dose physical exercise for 11 weeks. RESULTS: The return rate for post-intervention testing was 82 to 94% across groups. Weekly exercise amounted to 2,004 +/- 24 and 3,774 +/- 68 kcal, respectively, in MOD and HIGH. Cardiorespiratory fitness increased (p < 0.001) 18 +/- 3% in MOD and 17 +/- 3% in HIGH, and fat percentage decreased (p < 0.001) similarly in both exercise groups (MOD 32 +/- 1 to 29 +/- 1%; HIGH 30 +/- 1 to 27 +/- 1%). Peripheral insulin sensitivity increased (p < 0.01) (MOD 28 +/- 7%; HIGH 36 +/- 8%) and the homeostasis model assessment of insulin resistance decreased (p < 0.05) (MOD -17 +/- 7%; HIGH -18 +/- 10%). The number of subjects meeting the criteria of the metabolic syndrome decreased by 78% in MOD (p < 0.01) and by 80% in HIGH (p < 0.05). General health assessed by questionnaire increased similarly in MOD (p < 0.05) and HIGH (p < 0.01). CONCLUSIONS: Only minor additional health benefits were found when exercising about 3,800 as opposed to about 2,000 kcal/week in young moderately overweight men. This finding may have important public health implications.

Full text (sometimes free) may be available at these link(s):      help

• DOI
• PubMed
• PDF locator
• publisher