Article from IDEA Fitness Journal February 2014 issue
The
top titans of exercise—resistance exercise and cardiovascular exercise—continue
to duke it out for the title of best fitness protocol. When it comes to obese girls, researchers
believe they have a champion: cardio.
To
come to this conclusion, the researchers recruited 44 obese girls, aged 12-18,
and assigned them to resistance exercise, cardiovascular exercise, or a
nonexercise control group for 3 months.
Measures included body weight, waist circumference, oral glucose,
insulin sensitivity, body fat, cardiorespiratory fitness, muscular fitness and
more.
The
exercise protocols consisted of three 60-minute sessions per week. Participants in the cardiovascular exercise group
wore heart-rate monitors and were instructed to achieve 60%-75% VO2 peak. No information was provided as to the type of
cardiovascular activity performed. The
resistance exercise group completed 1-2 sets (8-12 reps per set) of leg press,
leg extension, leg flexion, chest press, latissimus pull-down, seated row,
biceps curl and triceps extension-all performed at 60% of 1-repetition
maximum. Single sets of push-ups and
sit-ups were also performed.
The
girls were asked to maintain a “weight-maintenance diet” (55%-60% carbohydrate,
15%-20% protein and 25%-30% fat) throughout the 3-month intervention.
By
the end of the study, neither exercise group had lost any weight; however, the
cardio group did lose fat: “Compared with control, significant reductions in
visceral adipose tissue and intrahepatic lipid, and improvement in insulin
sensitivity were observed in the cardiovascular exercise group, but not the
resistance exercise group,” explained the study authors. “in obese adolescent girls, aerobic exercise,
but not resistance exercise, is effective in reducing liver fat, visceral adipose and improving insulin sensitivity independent of weight loss or
calorie restriction.”
