Welcome to the final installment of understanding your body's energy production, Metabolism Matters. In this last section I will discuss how exercise effects your metabolism, strategies to boost your metabolism, and the cumulative effect of calorie burning during and after exercise
Let's jump right in.
Last week I talked about the other two factors of your body's caloric consumption. Remember that the Thermic Effect of Exercise (TEE) accounts for between 10-20% of your body's metabolism. Thermic Effect of Feeding (TEF) accounts for 10-20% and Resting Energy Expenditure (REE) accounts for 60-70%.
Exercise in itself has the potential to consume a lot of calories. But only counting the calories used DURING exercise is a bit short sighted. And we don't want short sighted, we want long term weight loss success! So the real effect we are after is a long term boost in metabolism, in addition to using a lot of calories during exercise.
As was mentioned, exercise has the potential to use quite a bit of energy (i.e. calories). Running at a 10 min/mile pace uses 680 calories over the course of an hour, whereas walking at half that speed uses 280 calories per hour (isn't it interesting that running twice the speed uses almost 2.5 times the amount of calories??). 1 hour of circuit training uses 540 calories per hour.
Although running does use more calories during the activity, there is a longer term effect that goes often unconsidered.
And that "magic pill" is: muscle.
Muscle has a very high metabolism at rest. Remember when we talked about REE and the goal of any fat loss program should be to increase REE. Well resistance training and adding muscle to your frame is the way to go about that. Your body uses the greatest percentage of fat at rest. Not the greatest absolute quantity, only the greatest percentage.
Adding muscle gives your fat burning fire a little extra boost! The more muscle you have, the higher your metabolic rate, the more fat you burn at rest. Remember this one thing: Fat burns in the flame of muscle.
Regarding interval training for fat loss, the goal is similar: increase REE beyond just the exercise session. Fortunately, interval training does this for us. Not only does it use a lot of energy during the intervals, but it also increases EPOC.
EPOC is Excess Post-exercise Oxygen Consumption. When we first begin exercising we develop what is called an oxygen deficit. When you hit a steady state, such as occurs when you hit a jogging/walking pace and hold it for 20 minutes, your body is able to meet the demands being placed on it. However, it still needs to make up that oxygen deficit.
So after you finish exercising, your metabolism stays elevated because your body is paying back the debt it has incurred. Usually after a 20 minute steady state run at 65% max effort, EPOC is elevated between 20-50 minutes. Intervals send this EPOC through the roof and into the next day because you never hit steady state! Instead you are accruing a debt faster than the US government and it's going to take it a while to pay it back!
The result?? An increased metabolism for up to 48 hours following interval training!!
So the take home message of this long post: Add muscle through resistance training to increase your resting metabolic rate AND run intervals to give it an even greater boost over the next few days!