Strength Training Key to Change

Losing weight is hard enough, but research shows that keeping it off may be even more difficult. The body is a dynamic system that is always trying to achieve homeostasis. It wants to be in balance.

When you create an energy deficit with the goal of losing weight, the body responds by altering the amount of calories it uses to sustain itself, especially over the long term. Known as metabolic adaptation, this reduction in energy expenditure makes it much harder for people to maintain weight loss.

This conundrum has led scientists to search for ways to improve metabolism and offset the drop in energy expenditure that comes from dieting. Exercise, though not that helpful for losing weight, is a powerful tool for keeping it off. A recent study shows that the type of exercise matters: Strength training has unique physiological benefits that support metabolism and help you maintain fat loss long term.

USE STRENGTH TRAINING TO KEEP FAT OFF

Preserving muscle is a top priority when you are losing weight. Not only is muscle protective for health and associated with longevity, it is your metabolic engine, burning three times as many calories as body fat. It’s also the main disposal site for blood sugar, consuming as much as 90 percent of the glucose in your blood.

Muscle takes a major hit during weight loss: For the average overweight person, 30 to 40 percent of weight loss is from muscle. Lean people lose even more, averaging as much as 60 percent muscle lost. One go-to strategy for shifting the curve so that you lose more fat and less muscle is to increase protein intake during weight loss. Another is exercise.

One study found that by doing strength training, you can maintain muscle mass, supporting metabolic rate. This study took 140 sedentary overweight women and put them on a radical 800 calorie-a-day diet to lose 25 pounds. A third of the women were assigned a weight-training program, a third did aerobic exercise for 40 minutes 3 times a week, and a third did no exercise. 

At the end of the study, the women who lifted weights gained 0.3 kg of muscle maintaining their metabolic “engine” and experiencing zero drop in metabolic rate. In contrast, the other two groups each lost muscle and saw their daily energy expenditure shrink.

In the aerobic group the loss was small—1.2 pounds, which translated to a decrease in total energy expenditure of 63 calories, but for the sedentary control group the decrease was substantial. The women who did no exercise lost 2.2 pounds of muscle and decreased energy expenditure by a whopping 259 calories. Only the women who lifted weights were in a position to keep the fat off in the long run, whereas the other two groups were pretty much set up for failure down the road. 

But that’s not the whole story. Most interesting was the fact that the group that weight trained became more active in daily life, which is uncommon during weight loss. One of the challenges to keeping weight off is that people tend to get lazier when they drop weight. Instead, the weight training group increased the amount of calories they burned from something called NEAT, which is made up of the calories you burn moving around during the day, not including exercise. NEAT stands for “non-exercise activity thermogenesis,” and it contributes a substantial amount to your daily calorie burn.

Researchers believe that the women who lifted weights had better mobility and walking economy and they improved how they felt about their bodies, which allowed them to be more active in spontaneous activity. At the same time, many of the women who did not exercise showed worse movement economy, even though they now weighed less.

As predicted, the non-exercising control group became more sedentary than before losing the weight, despite being leaner—a situation that would make it virtually impossible to avoid fat regain in the near future.

TAKE AWAYS:

1. To sustain fat loss, your number one priority should be to train with weights 2 to 4 times a week.

2. Consciously focus on being as active as possible in daily life to boost the amount of “NEAT” calories you burn. 

3. Avoid sitting for long periods of time. Try to get up at least every hour, shooting for some movement every 15 to 30 minutes.

4. Reduce exposure to screens. Studies consistently show that the more leisure screen time you have, the lower your daily energy expenditure will be even if you work out. 

5. Eat enough protein to maintain muscle mass. Studies show a minimum of 1.6 g/kg (0.73 g/pound of body weight) of protein can help preserve muscle during weight loss. 

References

Hunter, G., et. al. Exercise Training and Energy Expenditure following Weight Loss. Medicine And Science And Sports And Exercise. 2015. 47(9): 1950–1957. Article by Poliquin Editorial Team