How to Increase Your Fat Burn in 48 Hours

When trying to get that beach body, which workout should you perform: A 4 to 5-mile jog or a 50-minute lift? Turns out, researchers have discovered lifting will elevate your metabolism for up to 48 hours after your workout due to microtraumas to the muscle fiber. Unfortunately, after a jog, your metabolism is not elevated.

Dr. Jeff Volek, an Associate Professor in the #1 ranked Department of Kinesiology at the University of Connecticut, explains why microtraumas are so important.

At its most basic level is the SAID principle, an acronym for the specific adaptation to imposed demand. Think of this as the use-it-or-lose-it law. When a muscle fiber is exposed to a regular challenge, it makes structural adaptations in order to reduce stress on the body. In other words, it might grow bigger and stronger, or become more resistant to fatigue. Which is why you can perform everyday functions – like walking up the stairs or picking up a light object – with little effort.

Now let’s apply the SAID principle to your workout.

When you lift weights, you cause tiny tears in your muscle fibers, known as microtrauma. In this process, amino acids are used to repair and reinforce the fibers, making the fibers resistant to damage in the future. And although this happens at a microscopic level, the effect becomes visibly evident over time (assuming you have adequate nutrition) – in the form of bigger arms, broader shoulders, and a thicker chest. Consider it human adaptation at its finest. There’s another benefit to this microtrauma: Repairing your muscle fibers is an expensive metabolic process. That is, it requires calories, which results in raising your metabolism for hours after your workout is over. This is frequently referred to as the after burn effect. It’s important to note that the after burn effect is unique to exercise that heavily challenges your muscles. So it does not occur with aerobic training, like when you run 4 or 5 miles at a steady pace.

Now that you understand the science of microtraumas and why they are so important, lets take a look at 2 different studies.

Researchers at the University of Texas Medical Branch in Galveston have reported that muscle protein synthesis, is elevated for up to 48 hours after resistance training session. So if you work out on Monday at 7pm, your body is in muscle-growth mode until Wednesday at 7pm. After 48 hours, though, the biological stimulus for your body to build new muscle returns to normal.

Turns out, that’s similar to the duration your metabolism is elevated after a heavy-lifting workout, too. University of Wisconsin scientists found that performing 12 total sets – 4 sets bench press, power clean, and squat – increased metabolism for 39 hours after the training session.

What does this mean?

Lifting weights will increase your metabolism (requiring your body to use more calories than normal) in order to repair microtraumas to the muscle fiber. Microtraumas are tiny tears to the muscle in which the body utilized amino acids in order to repair and reinforce. After a hard lift, it can take up to 48 hours for the microtraumas to repair. Which means, your body burns more fat for an additional 48 hours. Because a jog does not cause microtraumas to the muscle fiber, the body does not need to repair itself after a workout. As a result, no increase in metabolism after your jog.

What are you to do?

Lift and lift hard. Embrace the thought that you are causing microtraumas to your muscle fiber which will elevate your metabolism for 48 hours afterwards. Not only will you be stronger and possibly bigger (assuming your nutrition is appropriate for gaining muscle mass), you will release even more fat vs. going for that 4 to 5-mile jog.


Steven Zahn

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