Continuing from the last Metabolic Mindhack™, I want to continue removing the “time” barrier for shedding unwanted fat.

I know how hard it is to get an hour to exercise some days. Even when I block off time, sometimes things go haywire, and I can’t dedicate an uninterrupted hour. What if you can only find 30 minutes here and there? Or only 15 minutes? Maybe 10 minutes? It’s hard to find a good excuse to not have some time for exercise during the day. Especially if you are focusing on and prioritizing it.

The question I want to explore in this post is whether you can actually split up your exercise sessions to achieve the same, if not better, results.

In a 2007 study found in the Journal of Applied Physiology, they explored this question. The scientists set out to determine if fat metabolism was different if you did a single bout of “prolonged” exercise (in this case, 60-minutes), or two sessions of equivalent exercise – same total duration, same intensity (30-minutes x 2, with a 20 minute rest in between sessions). The test subjects exercised on a stationary bike at moderate intensity (60% maximal oxygen uptake).

In the first 30 minutes of both trials, growth hormone (linked to abdominal fat loss), and blood epinephrine and norepinephrine levels (linked to hormone sensitive lipase, an enzyme that controls fat burning by releasing fatty acids from fat cells) were significantly increased. So far so good.

In the repeated bout trial, there was a significant increase in free fatty acids circulating in the blood stream during the 20-minute rest.

In the final 30-minutes of exercise, free fatty acids and epinephrine were statistically higher in the repeated trial than the continuous bout. Also, blood glucose and insulin (higher insulin promotes fat storage) were significantly lower in the repeated trial.

Finally, the researchers found that fat oxidation was a larger contributor to total energy expenditure in the repeated trial that the continuous bout of exercise. Basically, they found that you burn more fat by splitting up your cardio routine [Goto K, Tanaka K, Ishii N, Mizuno A, Takamatsu K.Enhancement of Fat Metabolism by Repeated Bouts of Moderate Endurance Exercise. Journal of Applied Physiology, June 2007; 102:(6) 2158-2164.]

In 2011, another team led by Dr. Goto tested the effects of a continuous 30-minute bout of exercise versus 3 x 10-minute bouts with a 10-minute rest in between. Again, they found that the results “suggest that the repetition of 10-min of moderate exercise can contribute to greater exercise-induced fat oxidation compared with a single 30-min bout of continuous exercise.”

In both of these studies, there were (relatively) short rest periods followed by more exercise. What happens when you rest for hours at a time, and only exercise when convenient?

The study that is most often cited is 1995 study found in the International Journal of Obesity Related Metabolic Disorders. In this landmark study, participants (56 obese, sedentary females) were asked to exercise 5 days per week, increasing duration from 20 minutes to 40 minutes over a 20-week period. One group did all of their exercise in a single session. The other group did their exercise in 10 minute increments, spread throughout the day.

The multiple-session group reported exercising on more days than their single-session counterparts (87.3 days versus 69.1 days on average). They also reported exercising more minutes per week – 223.8 minutes versus 188.2 minutes on average. That’s a difference of 35 minutes – basically an additional exercise session per week!

As you might imagine, the multiple-session group lost more weight (8.9 kilograms; 19.6 pounds) than the single session-group (6.4 kilograms; 14 pounds).

Now, in the first two studies I mentioned, we see that fat metabolism is greater for the multiple-bout approach, but there is a rest duration variable. In the last study, the rest variable is removed, but the weight loss is at least partially attributable to the increased amount of exercise performed.

If only there was a large review of the studies we could reference…

In 2009, a review was published in Sports Medicine. Here are what the authors found:

The majority of the intervention studies included in the review measured body mass, body composition or fat distribution before and after training. Although eight studies noted positive alterations in body composition following training, there is little consistency in the comparisons between the two exercise patterns. Four studies noted similar favourable alterations in body composition in both patterns, whereas three studies noted greater improvements following the accumulated exercise and one study reported greater improvement following the continuous approach [Murphy M, Blair S, Murtagh E. Accumulated versus Continuous Exercise for Health Benefit. Sports Medicine. January 2009;39(1):29-43.]

So, over the long term, it looks like the studies say (generally) that breaking the exercises down into smaller intervals of 10-minutes or greater is at least as good as doing a longer session for reducing body weight (yes, I know that mass and weight are different, but since we all live on the earth, the difference is more philosophical than practical).

Let’s also not forget what we learned about growth hormone, exercise and fat loss.

From a practical standpoint, especially for beginners, this is a great way to ease into an exercise program (this theory forms the foundation of the Metabolic Mayhem® beginners program).  For the rest of us, intermittent exercise also has many benefits, as we’ve discussed, and a variation on this theme is also found in the intermediate/advanced Metabolic Mayhem® course.

If you’re looking to shed pounds, “time” is no longer an excuse. As I mentioned in an earlier Metabolic Mindhack™, you can find 10 minutes just by using your DVR. Next time you think you want a snack at work, or you need a “break”, instead of checking email or reading TMZ, get up and walk for 10 or 15 minutes.

Get out and take a brisk walk for 10 minutes, 3 or 4 times per day. Your body will thank you for it in the long run.

Now I’d like to hear what you think. Do you agree? Disagree?
Hit me with your comments and questions below!

P.S. If you liked this post, please “like”, “tweet”, and “+1″ it.

Previous: Make it a Priority

Next: Bonus – Be N.E.A.T.

If I asked you whether or not shedding fat were a priority for you, I believe the vast majority of you would say it was. I also believe that if I asked you what was the most challenging thing about working out, a large portion of you would say that finding the time to exercise is a huge obstacle. Let’s talk about that for a minute.

I get it, because I’m a lot like you. I don’t hang out in the gym all day. I have a life. A busy life. Very busy, in fact (did I mention it was busy?) It hardly feels like I have time to breathe sometimes, with driving kids to school, sitting in traffic to go sit behind my desk or in a conference room, dinner time and play time and then bed time (for the kids).  You know what I mean, right?

So how do you find time to exercise? It took me a while to come up with a reasonable answer. And then I had my “ah ha!” moment. Here it is…

Let me turn that question on it’s ear for a minute… you know, pull a Dead Poet’s Society moment out of the air and look at things in a different way.

Let’s ask this question:

How do you find time to take your kids to school, soccer practice or swim lessons? How do you find time to sit in traffic? How do you find time to work 8 hours per day? How do you find time to watch TV for 2.7 hours every night?

It’s because you’ve made those things a priority in your life. You have allocated your scarce resource – time – to do these things. And in between all of these things are the hundreds of moments of procrastination that take place – getting sucked into twitter and Facebook. Spending 20 minutes chatting at the “water-cooler” as it were. Surfing the web.

Me? Exercise is a priority. When I roll out of bed in the morning, I usually roll right into a 10 to 15 minute Morning Metabolic Motivator™ routine. Before I do anything else. That way, I start the day off with a feeling of accomplishment, and I know if something happens during the day and my schedule completely implodes on me (which we all know happens), I exercised.

But it doesn’t stop there. On my calendar, there are two times that are sacred, and they are some of the last to get rescheduled. I schedule time to workout every day. I block off one hour on my calendar. Some days I have time to make that a gym workout, other days I don’t, depending on how the day shapes up. On days I don’t, I get in some quality, fat-burning steady state cardio in the form of a 15-minute walk. I get out and clear my head, burn some calories and refresh myself.

And there is an hour blocked off at 9PM every night. That’s when my kids go to bed. If I didn’t get my full workout in during the day, I do it then. No excuses. If I did get it in, then I have the option of going for another walk, doing some Metabolic Intervals or doing a Metabolic Shred Circuit™.

Because I’m making exercise a priority, I’ve given myself options on what Metabolic Mayhem® routines to do and when.

Ultimately, though, the point is, I make time to exercise, and you can to. You just have to do it. But unless you make exercising a priority, unless working out becomes more important to you than, say, watching TV, you will always be saying “I don’t have time.”

Now I’d like to hear what you think. Do you agree? Disagree?
Hit me with your comments and questions below!

P.S. If you liked this post, please “like”, “tweet”, and “+1″ it.

Next: Less is More, More is Better

Previous: Make it Worth It