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Train Your Body to Burn Fat for 24 Hours Post-Workout

posted Jun 24, 2015, 1:13 PM by Walk Strong Calgary   [ updated Jun 29, 2018, 5:48 PM ]
If you're like me, you've likely been coached along the way through various resources in the mindset that a longer aerobic workout at moderate intensity will burn fat. While true, we often forget about what's going on in the body during a very critical period - the recovery time between workouts. 

Recovery is when tissue repair occurs and the body also replenishes glycogen in the muscles through sources of glucose in the diet. This probably isn't news to you... but what you may not realize is that there's more going on, and it involves what your body recognizes as a fuel source between workouts. It may surprise you to know that you may not be burning     (image courtesy stockimages
as much fat as you could be. You can train your body to
burn fat during recovery through your exercise mode.  

When it comes to fat in the body, it's simple - we either burn it or store it. In a typical aerobic workout, we know that it takes about 20 minutes to get into the fat stores in your body, and while we celebrate fat burning as a benefit of cardio training, we actually have the potential to burn much more. It comes down an important factor in the body's inner workings, and understanding this one principle may change the way you plan your workout regime:  

Your body will burn the exact opposite of what it burned in your workout for 
up to 24 hours post-exercise. 

This means that if you burn fat during your workouts, you'll burn glucose for fuel during recovery, yet we know the body needs to replenish glucose for the muscles (glucose is converted to glycogen in muscle tissue). It can't do that efficiently if it's using it for fuel at the same time. 

A workout that targets fat burning is actually conditioning your body to 
(image courtesy Salvatore Vuono    recognize that specific fuel as an energy source for exercise, and it               keeps right on storing it between exercise bouts. It becomes a cycle that 
                                               can make it difficult to lose fat because the body wants to keep it in reserve for when it's needed. If you're burning glucose during your recovery period, you may actually be using up the fuel needed in the muscles instead of replenishing it, which in essence defeats the purpose. Depriving your muscles of glycogen can impact lean body mass, a key component to maintaining a super-charged metabolism. 

What if we were able to turn that around and have your body burning fat between workouts instead? It comes down to a simple principle: 

The more glucose/glycogen you can burn during your workouts,
the more fat your body burns during recovery.

By training the body to recognize glucose/glycogen as the preferred fuel, we can start a cycle wherein the body focuses on burning fat during recovery while it builds up these two components as energy reserves. We can do just that, and in shorter workouts!

This is certainly not a new concept. Interval training has been around for some time, and High Intensity Interval Training (HIIT) {sometimes referred to as Sprint Interval Training (SIT), surges or bursts}, is a more advanced version, as is Tabata (most intense). Olympic athletes have been doing it for years, and it's become a popular mode in the fitness industry.  The ACSM link below provides a good description of HIIT along with the benefits.

The goal behind this training mode is to force your body to use up its muscle glycogen and burn calories/carbs at your body's maximal rate. In order to really reap the benefits of this type of training, however, Dr. Al Sears, MD recommends pushing yourself to the max (100% effort) during the high-speed intervals. Your body may demand a complete recovery period (i.e., you'll be panting and want to stop to rest), but if you force yourself to keep moving, even if your lungs are burning and crying out for more oxygen, according to Dr. Sears, " delaying the recovery of oxygen, you're pushing your body to literally use every last high output fuel store it has. And when you forcibly empty your tanks, the resulting fat loss will be more intense and more noticeable - and it will happen at double the rate." (Dr. Al Sears, MD is founder of the Center for Health and Wellness and America's #1 Anti-Aging Pioneer).                                                              (image courtesy Stuart Miles 
One of the reasons this mode of training has become so popular is 
because of its versatility. It can be modified for all fitness levels and works in many types of activities including cycling, swimming, walking, running, elliptical, group exercise classes, etc. 

There's another great advantage to this type of training, and it comes down to the number one reason people state for not exercising: Time. With this type of training, you can get similar benefits (if not greater) of a longer workout in a shorter period of time. As mentioned above, the secret is in the intensity level.  

When you do surges, during the short, high-speed intervals, your body is working anaerobically, so it doesn't have time to get into fat burning. Keep the intervals short (20-30 seconds to a minute) at your maximum intensity - this will vary by individual, but your goal is to work at 100% effort for the entire high-speed portion. A great way to do this is through sprints. Walk at Home's new MP4 Player is a super tool for this - it includes a segment near the end of the music mix that incorporates a moderate walking pace followed by a 30-second sprint interval, repeated three times. It's easy to do a similar cycle on your own out in the park. Whatever you do, however, don't start here - if you're new to exercise or haven't done sprinting in years, you'll want to work your way up to this level, and please be sure to warm up well.

  (image courtesy imagerymajestic      By doing these short bursts at maximum effort, you burn glucose for
                energy, not fat... so after your workout, if the science holds true, you 
                                                   should be burning fat for up to 24 hours and building up glucose/ glycogen stores. According to Dr. Sears, you only need one set of HIIT for it to be effective, which can cut your workout time down. How does that sound to you? 

There are some great examples of surges in sports - soccer, football, broomball - anything where the players are moving at a moderate pace with sudden, short bursts at 100% effort or close to it. As mention
ed earlier, Olympic athletes have been using this concept for decades - you can train like an Olympian and get fabulous results in less time than traditional workouts.

Over the years, we've bought in to the idea that longer is better for fat burning and other benefits, but when you think about it, long-duration exercise isn't natural. The HIIT or Tabata type of training with recovery intervals recreates what your body needs for building fitness. It also produces amazing benefits, including increased power, a stronger immune system, 
    (image courtesy pal2iyawit       reduced inflammation in the body, increased oxygen 
                                                                          levels in the blood, less body fat, and increased longevity. It also does not push the body into stress mode, which triggers an increase in cortisol production from the adrenal gland - cortisol eats away at muscle tissue and causes the body to store more fat - that's part of the 'fight or flight' mechanism that's built into our systems. While longer duration workouts certainly play a role and I encourage you to keep them in your routine for variety and endurance training, adding surge workouts can make a huge difference. 

You can start incorporating this training mode into your routine right now. When you're out for your fitness walk, add a short sprint here and there or jog up hills, or leave your bike in a harder gear on hills. Incorporate bursts of intensity into your routine where you can and gradually increase frequency and intensity as you build endurance. Then add an actual surge workout. The ACSM has some tips on developing a HIIT program on the link below as does Dr. Sears, but you can do a very basic plan to get started - a mile of brisk walking for a good warm up, then sprint at your maximum speed for 20-30 seconds, walk at a moderate pace for a few minutes, then do another sprint at 100% effort. Cycle through           
(image courtesy tuelekza
this 3-4 times or more, depending on your time, and 
of course, stretch well after a cool down. Add a second surge/burst workout to your week when you feel ready, then a third. Let me know how you make out with it!


Nancy Ehle is a Certified Walk Leader through Leslie Sansone's Walk Live program as well as a Group Fitness Instructor through the American Council on Exercise. Other certifications include Health Coach and in Sports Nutrition, and she holds several industry specialties. Her enthusiasm and passion for health are infections! Follow Nancy on Facebook:  Walk Strong Calgary