FRIDAY, April 22 (HealthDay News) -- Brief, intense exercise is a time-efficient alternative to traditional endurance training and reduces the level of various markers of cardiovascular diseases (CVD) in adolescents, according to a study published online April 4 in the American Journal of Human Biology.
Duncan S. Buchan, from the University of the West of Scotland in Hamilton, U.K., and colleagues compared the effects of a brief, intense exercise intervention with traditional endurance exercise on new and traditional markers of CVD in 47 boys and 10 girls (16.4±0.7 years of age). The participants were divided into a moderate (MOD) group, a high-intensity (HIT) group, and a control group. Over a seven-week intervention period, participants carried out three weekly exercise sessions. Each HIT session involved four to six repeats of maximal sprint running within a 20-meter area with 20 to 30 seconds recovery, with the sessions lasting for a total of 63 minutes during the intervention. The MOD sessions were 20 minutes of continuous running within a 20-meter area at approximately 70 percent maximal oxygen uptake (VO2max) lasting a total of 420 minutes during the intervention.
The researchers found that total estimated energy expenditure was approximately 907.2 kcal in the HIT group and 4,410 kcal in the MOD group. In the HIT group, significant improvements (P ≤ 0.05) were found in systolic blood pressure, aerobic fitness, and body mass index (BMI) post intervention. Significant improvements (P ≤ 0.05) were seen in aerobic fitness, percentage body fat, BMI, fibrinogen, plasminogen activator inhibitor-1, and insulin concentrations in the MOD group.
"Different exercise intensities and durations may have different cardioprotective effects on youth," the authors write. "Although positive adaptations were noted in the metabolic profiles of the participants in a traditional exercise intervention, further research is needed to evaluate the use of intermittent activity protocols."