If you missed part I about why jogging will not make you thin read that first.
If traditional weight loss exercise like jogging won't actually take off the pounds, what will? Interval training. In part I we looked at half of an Australian research paper (group 1), so lets take a look at the other half (group 2):
In just half the time, the interval group lost body fat while the steady state group actually got fatter. (1)
We've known about this for at least 15 years here's the oldest study I've found comparing regular steady-state aerobic exercise to intense interval training: In 1994 Canadian researchers put group 1 on an interval program and group 2 on a steady state aerobic program. Here are the results.
* 15 weeks of intervals
* They burned only 13,614 calories during their workouts (less than HALF as many as group 2)
* 20 week steady-state aerobic program (5 weeks more)
* they burned 28,661 calories during their workouts
Group 1 lost 450% more fat than group 2. This is in spite of the fact that the interval group had shorter workouts that burned fewer calories. (2)
Why Interval Training Is So Much Better?
We're not entirely sure. We used to think that there was this thing called EPOC - a huge metabolic boost after an intense workout that created a large calorie deficit. But, it turns out that the EPOC is nowhere near big enough to account for the huge difference between interval training and aerobic training.
After talking to (who knows more about obesity and public health than anyone else on planet Earth - no exaggeration at all), and taking some physiology and biochemistry classes at UMD I have a new theory:
Interval training only consumes your stored carbs for fuel. Body-fat is fundamentally regulated by the hormone insulin. More insulin = more body fat and vice versa. When you deplete your muscles carbohydrate stores (glycogen) you improve your sensitivity to insulin. The more sensitive you are to insulin the less insulin you need to make to handle the same amount of food and/or carbohydrates. The increased sensitivity to insulin is temporary, but if you do high intensity exercise like interval and resistance training you will appear to be someone with better insulin sensitivity (have less body-fat). (3-6)
That is the primary way that interval training creates superior fat-loss.
The secondary way is that intense exercise releases stuff called catecholamines. These are chemicals like epinephrine and norepinephrine that stimulate the release of fat from your fat cells to be burned off. The calories consumed by the workout are probably irrelevant.
I could be totally wrong, but that doesn't matter. it still works far better, in far less time and is more fun.
More Fat-Loss In Less Time
Here's how you actually reap the benefit. For accelerated fat-loss you want to get 3 interval sessions in per week. These can be done with no equipment other than a watch, so you don't actually need to go to the gym.
Warm-up: 3 to 5 min moderate pace (walking and jogging for outdoor running)
Round #1: (using the running example)
*run at 90% of fast as you can for 60 sec
*walk briskly for 120 sec
Repeat for a total of 4 rounds
Cool down: 3 to 5 min moderate pace (walking and jogging for outdoor running)
You should be done! If you feel like you could have done more rounds, that's because you didn't work hard enough on the fast part. For best results use interval training with metabolic resistance training and eat better too. This will create a synergy that will strip fat away quickly.
1. Trapp EG and Boutcher SH. Fat loss following 15 weeks of high intensity, intermittent cycle training. Fat Loss Laboratory, Faculty of Medicine,
University of New South Wales, Sydney, Australia
2. Tremblay A, Simoneau JA, Bouchard C. Impact of exercise intensity on body fatness and skeletal muscle metabolism.
Metabolism. (1994); 43(7):814-8
3. Joslin. Elliot. Et al. Joslin’s Diabetes Mellitus. Lippincott Williams & Wilkins. 13th edition, 1994
4. Nussey, Stephen. et al. Endocrinology: An Integrated Approach. Informa HealthCare, 1st edition, 2001
5. Kronenberg MD, Henry M. et al. Williams Textbook of Endocrinology. Saunders. 11th edition, 2008
6. Lehninger, Albert. Et al. Lehninger Principles of Biochemistry. W. H. Freeman. 5th edition. 2008
- 40 minutes of steady state aerobics (TWICE as much exercise)
- 3 days per week
- In 15 weeks, they GAINED an average of 1lbs of fat
- 20 minutes of high intensity interval training (at week one they did only 5 minutes)
- 3 days per week
- In 15 weeks, they lost an average of 5.5lbs of fat