Abstract
BACKGROUND: High prevalence of metabolic diseases among young professional athletes with large body sizes has raised growing attention. However, few studies specifically examined whether additional aerobic exercise provides cardiometabolic beneficial effect among these young athletes under regularly intensive strength training. OBJECTIVE: We conducted a pilot trial to evaluate the effects of aerobic exercise on overall metabolic syndrome (MetS), individual MetS components, and aerobic capacity among metabolically unhealthy athletes in the heaviest-weight class. METHODS: Forty-nine professional athletes aged 15-30 years had large body weights (mean weight of 131 ± 15.5 kg and 108 ± 15.8 kg and mean BMI of 39.4 ± 4.7 kg/m(2) and 36.4 ± 5.1 kg/m(2) for 26 men and 23 women, respectively). They completed a supervised moderate intensity (maximal heart rate: 140-170 beats/min for 30-70 min/day) aerobic exercise training for 12 weeks. We collected and measured metabolic parameters and aerobic capacity for all participants before and after 12 weeks of aerobic exercise training. RESULTS: At baseline, 42 (86 %) of all 49 metabolically abnormal athletes were diagnosed as MetS according to the NCEP ATP III criteria (≥3 MetS components). After aerobic exercise training, 30 % (13/42) of MetS individuals tended to become free of MetS (<3 MetS components), decreasing the prevalence of MetS by 30.4 % (from 17 to 10) in women and 23.1 % (from 25 to 19) in men (P = 0.001). All individual components of MetS, including fasting glucose levels, lipid profile, and blood pressure, were also significantly improved (all P-values <0.05). Overall and central obesity indexes, including BMI, waist circumference, Waist-hip ratio, and abdominal fat ratio, were significantly decreased in men whereas only overall adiposity indexes, such as BMI and body fat percentage, were significantly reduced in women. Also, participants' aerobic capacities were also significantly enhanced with longer running distances and decreased heart rates (all P-values <0.05). CONCLUSIONS: Our pilot trial showed that moderate intensity aerobic exercise effectively improved cardiometabolic parameters in metabolically unhealthy professional athletes with routinely intensive strength training. Its long-term cardiovascular effects will be evaluated by future randomized controlled trials with well-designed exercise modalities.