Most people start a weight lifting routine with hopes of building muscle mass, but there are other positive byproducts that come from it as well. Lifting weights, and exercise in general, can boost nearly every aspect of overall health.
One benefit of strength training, in certain circumstances, is weight loss. Lifting weights can boost metabolism in both the short term and long term. Adding muscle mass can also increase carbohydrate storage, allowing for people to consume more carbs in their diet on a consistent basis.
Short Term Metabolism
An intense workout can elevate metabolism in the short run for upwards of about 48 hours. This is particularly evident in new lifters since they have not yet adapted to the exercise stimulus. Intermediate and advanced trainees will still experience this elevation in metabolism, but typically for a shorter period of time (unless it is an especially grueling workout).
This metabolic boost is caused by something called excess post exercise oxygen consumption (EPOC) . It’s important to understand that the body’s goal is always to achieve balance. After a tough workout, the body has to work overtime to return to equilibrium. This is sometimes called oxygen debt since the body will up take more oxygen in order to recover from the workout. There is an increase in fuel utilization as well, as carbohydrates and fats are broken down to aid in this recovery process.
Remember that this acute metabolic boost is only in response to tough workouts. You may even consider this a dose-dependent response; the tougher the workout the greater the increase in short-term metabolism.
This supposed exercise calorie-burning phenomenon is a good reason to not stress over how many calories are burned in the workout itself. With the popularity of fitness studios like orangetheory, which put an emphasis on total calories burned during the workout, people may lose sight of the big picture. Just because you remove the fitness tracker after the workout doesn’t mean the calorie burn is finished.
A one hour brisk walk may burn more calories than a 20-minute interval workout within the confines of the workout itself. However this does not take into consideration the afterburn effect of that 20 minute intense workout. Once the one hour walk is over, there won’t be much of a calorie burn post exercise since the activity wasn’t all that challenging. An interval workout can leave someone totally spent and elevate their heart rate to a very high level (sometimes even approaching 200bpm).
There will be a prolonged calorie burn post exercise with a high intensity, short duration workout. It doesn’t even have to be cardio based. An intense lifting session, which is the basis for this article, can have a similar effect. So it’s important not to get discouraged when looking at total calories burned during the workout itself.
Long Term Metabolism
In a roundabout way, lifting weights boosts metabolism in the long run as well. This is due to the increased muscle mass which occurs from lifting and diet. Adding muscle increases an individual’s resting metabolic rate.
You may have heard people say that muscle burns more calories than fat. Muscle tissue is more metabolically active and burns more calories at rest than fat.
A pound of muscle burns about 5 calories per hour at rest, while the pound of fat burns about 2 calories per hour at rest. On paper this may not seem like a considerable difference, but you have to look at it proportionally. Muscle burns 2.5x more calories per hour. Over the course of a 24 hour day, this really adds up.
For example, say somebody lost 10 lb of fat on a new exercise program and also gained 10 lb of muscle (bare with me, trying to make the math easy). Despite not having any changes in total body weight, this individual now burns 720 more calories over the course of the day just by changing their body composition. Of course putting on 10 lb of muscle takes quite a bit of time, years even. But this example illustrates how looking at things in relative terms can make a big difference.
Carbohydrate Storage
Carbs are the preferred fuel source for most physical activity. The body can store carbohydrates in the liver and also muscle tissue in the form of glycogen. Naturally, the more muscle you have the more opportunity there is for carbohydrate storage. Over time, as you gain muscle mass, you can have an increased threshold for how many carbs you can eat in a day (and who doesn’t want an excuse to eat more carbs).
You can also store fat in muscle tissue in the form of intramuscular triglycerides. But this storage capacity is not as large as carbohydrate/glycogen storage.
This enhanced tolerance for carbohydrates also works as a preventative measure against diabetes. Lifting weights makes the muscles more receptive to nutrients coming in. This is sometimes referred to as insulin sensitivity. The body requires less insulin to shuttle nutrients into cells, because the cells are already primed to absorb them due to the workout. This is why diabetics are often encouraged to begin an exercise program.
While this newfound nutrient storage capacity isn’t an increase in metabolism per se, it does allow for more food intake. Having more muscle is almost always a win.