Resistance and Cardiorespiratory Time-matched Exercise in Youth: A Randomized Clinical Trial (RCT:RCT)
Resistance and Cardiorespiratory Time-matched Exercise in Youth: A Randomized Clinical Trial (RCT:RCT)
The current epidemic rate of childhood obesity is a leading health concern as
 overweight/obese youth may suffer from comorbid conditions, once considered exclusive to
 adults. It has been suggested that physical inactivity is a major determinant of obesity and
 obesity-related health risk in children and adolescents. Recent studies in adults report that
 the combination of aerobic and resistance exercise is a better strategy than aerobic or
 resistance exercise alone for reducing risk factors for type 2 diabetes. Currently, the most
 effective exercise modality for concurrent reductions of adiposity, in particular abdominal
 fat, and risk factors for type 2 diabetes and cardiovascular disease (CVD) is unknown in
 adolescents. Therefore, we will employ a randomized trial to examine the effects of a
 long-term aerobic exercise, resistance exercise, and a combination of both exercise regimens
 on: 1) in vivo insulin sensitivity, glucose tolerance and risk for type 2 diabetes, 2) total
 adiposity, skeletal muscle mass, visceral adiposity and ectopic fat in the liver and skeletal
 muscle, and 3) traditional and non-traditional risk factors/markers for CVD in overweight
 boys and girls. We will recruit 168 sedentary overweight (BMI >85th percentile) adolescent
 boys and girls aged 12-17 years old and randomly assign them to one of three 6-month
 intervention groups (n = 56 each group): 1) aerobic exercise (180 min/week), 2) resistance
 exercise (180 min/week), or 3) aerobic and resistance exercise (180 min/week) group. A weight
 maintenance diet (55-60% carbohydrate, 15-20% protein, and 25-30% fat) will be prescribed and
 monitored for all groups, so that any changes in energy balance will be induced by exercise
 intervention alone (e.g., no calorie restriction). We believe that this proposed application
 will have a significant implication that is directly relevant for one in three American
 adolescents who are at increased risk of developing obesity-related co-morbidities.
Inclusion Criteria:

 Age 12-17 years

 -  BMI percentile for age and sex >-85% percentile and BMI <40 kg/m2

 -  No structured physical activity in the past 3 months prior to the study (not including
 school physical education classes)

 -  No significant weight changes (>2-3 kg/m2) in the past 3 months prior to the study

 Exclusion Criteria:

 -  Endocrine disorders (e.g., polycystic ovary syndrome, diabetes)

 -  Syndromic obesity

 -  Positive pregnancy test

 -  Use of chronic medications which influence glucose metabolism and body composition

 -  Chronic medical/psychiatric conditions preventing the ability to participate in the
 study.

 -  Anemia