A New Study
As if we needed more proof, a new study shows that resistance, or strength training, is key to preventing weight gain (and regain) and boosting metabolism.*
Study participants, all women, were all put on a low-calorie diet to keep nutrition constant and ensure weight loss. They were divided into three groups: (1) aerobic exercise 3x a week for 40 minutes, (2) resistance exercise 3x a week working the major muscle groups (2 sets of 10 reps for each move), and (3) control group that had no exercise training. Researchers then examined the impact of both activity-related energy expenditure and energy expenditure from movements occurring as part of daily activities. The latter is known as non-exercise activity thermogenesis, or NEAT.
The aerobic group did supervised indoor walking and/or jogging, gradually increasing intensity and duration (up to 40 minutes). The resistance training included leg extension, leg curl, squat, biceps curl, triceps extension, latissimus dorsi pull-down, bench press, military press, low-back extension, and bent-leg sit-up. You can do resistance training with weights, your body, or bands.
Resistance Training Wins Out
All the women lost an average of 25 lbs; however, daily energy expenditure, or calorie burn, differed widely among the three groups. Energy expenditure helps to counter the down-regulation of metabolism that results from weight loss. Here is what emerged:
Daily Energy Expenditure (calories) and Fat Loss (percent) for Aerobic vs. Resistance Training
|Study Group||Activity-Related Calorie Burn||Non-Exercise, or NEAT-Related Calorie Burn||Total Daily Change in Calorie Burn||Total Fat Loss|
|Aerobic||+13 kcals||-87 kcals||-63 kcals||10.1%|
|Resistance||+109 kcals||+61 kcals||+63 kcals||10.6%|
|No Exercise||-142 kcals||-143 kcals||-259 kcals||9.2%|
Not surprisingly, the no-exercise group had the worst calorie-burn results. Total daily energy expenditure decreased by 259 calories per day, reflecting the drop in metabolism due to weight loss. Activity-related energy expenditure fell by 142 calories per day, and NEAT-related energy expenditure decreased by 143 calories per day. These study results suggest that people on diet-only plans are susceptible to regaining the weight.
By contrast, resistance training appears to do the most good since building muscle boosts metabolism. In this study, participants who engaged in resistance training increased their calorie burn whether they were working out or walking to the mailbox.
Notice the difference in Total Fat Loss between the no-exercise group and the two groups that included exercise. If all three groups lost an average of 25 lbs, how could the resistance group lose 1.4 percentage points, or 15% more fat than the no-exercise group? The likely reason is that the no-exercise group lost some muscle as part of its 25-lb weight loss, while the resistance-exercise group gained muscle mass and probably lost additional fat to account for its 25-lb net loss. An earlier study (from 2010) supports me on this—keep reading!
What’s Unique about Resistance Training and Calorie Burn?
As the authors note, resistance training increases muscle mass, which also increases daily energy expenditure, or calorie burn, because muscle is more metabolically active than fat tissue. The authors also affirm the value of resistance training in increasing excess post-exercise oxygen consumption, which helps your body burn more calories even at rest and so contributes to greater total energy expenditure.
|Study after study shows that resistance training PLUS good nutrition decreases fat mass and improves muscle strength|
An earlier study** in the European Journal of Applied Physics examined two groups in their 60’s. Both were put on a DASH (Dietary Approaches to Stop Hypertension) diet, a research-based plan rich in fruits, vegetables, and low-fat or nonfat dairy. The DASH diet emphasizes whole grains and contains less refined grains compared with a typical diet. One group had no resistance training, and the other engaged in resistance training on three non-consecutive days. In 10 weeks, this is what happened (see table below).
Healthy Diet With and Without Resistance Training—Effects on Body Weight, Body Fat, and Muscle Gain
|Study Group||Weight Loss (%)||Body Fat Loss (%)||Muscle Loss or Gain (%)|
|DASH diet with resistance training||3.6%||11.2%||1.3% gain|
|DASH diet only||2%||.2%||2.7% loss|
Again, resistance training rules the day, prompting greater weight loss, much greater body fat loss and a 4% greater muscle gain over diet alone. Note that 2.7% muscle loss in the diet-only group—that’s what you want to avoid if you want to “keep the weight off.”
* Hunter GR et al. (2015). Exercise training and energy expenditure following weight loss. Medicine & Science in Sports & Exercise 47(9): 1950-57. AND
Kravitz L. (Jan. 2016). New clues to prevent weight regain. IDEA Fitness Journal 13(1): 16-18.
** Avilla et al. (2010). Effect of moderate intensity resistance training during weight loss on body composition and physical performance in overweight adults. Euro J Appl. Phys 109, 517-525.