The Fat-Burning Myth

It’s that time of year when athletes have gained a couple of excess pounds of flab and are starting to think about taking it off. The traditional method for doing this is by doing lots of long, slow miles. The slower you go, the better, according to this age-old way of exercising to reduce body weight. Zone 1 is perfect, right? But is that the most effective way?

In a classic study (Tremblay 1994) on this topic researchers at Laval University in Quebec, Canada had one group of subjects exercise at a low intensity (low heart rate zone 1) for 20 weeks. Another group did high-intensity intervals (15-90-second sprints at 60-70% of max power) for 15 weeks. The low-intensity group burned 28,757 Calories while the high-intensity group burned 13,829.

Guess what happened. The high-intensity group had much greater reductions in skin-fold measurements when expressed in relation to energy expended. This was the result of increased fat metabolism during periods of rest between training sessions. The high-intensity group also had significant increases in the enzymes that burn fat for fuel. The low-intensity group had no changes in these enzymes.

Note that the intensity of these two groups was extremely different. Low heart rate zone 1 is so easy you’d wonder if you were doing anything of value for your fitness. The high intensity was very high. It would be a mental challenge to do this workout several times a week for 15 weeks.

Realize that I’m not suggesting how you should train at this time of year. There’s a big difference between exercising for fat loss and for race performance. I typically see any extra weight my athletes have gained over the holidays gradually come off in the following weeks as training intensity increases gradually without going to extremes in training.

Comments

[Mike]

Joe - thanks for the post. If you had an athlete who wanted to peak for a stage race (with lots of climbing) in late April (16 weeks away) who was currently 8lbs over optimal race weight, what would your guidance be? .5 lb per week? take more off earlier in the 16 week period?

[Angela]

This year, I've included my own timed circuit (plyo combined with super sets - not crossfit) training right after warm-up then do my normal MS strength training routine in the gym. This 3x a week session combined with Z1/Z2 endurance rides for my body (we are all unique). I've noticed my body is getting leaner but gradually over this last 3 weeks.

I see many benefits so far in the circuit such as improving balance, functional, some cardio and core improvements.

I am experimenting to see if it helps burn more fat during base training. So far, it is helping but concerned about the intensity added during base training. It's a good intensity for about 15 mins.

Do you see any benefit or non-benefit in fat loss to including circuit training as part of MS during base? Would you recommend I continue to do these circuits during SM?

[erik sannebro]

Intresting. Do yoy have any results from your semi-scientific, personal study regarding fat burning??

[Joe Friel]

Angela--Keep it up!

[Joe Friel]

Mike--Gosh, I don't know enough about you to suggest what you should do in this situation. It's much more complex than that. The starting place might be with a nutritionist.

[Jim]

Joe, does the study say if the groups were performing the same the same amount of distance/time?

[Joe Friel]

Jim--The low intensity group did significantly more total training time/distance than the high-intensity group. You can read the details here: http://tinyurl.com/btutt8g (Thanks, Fred Moyer).

[Ev_Ex]

In my opinion the best thing is to keep a healthy diet all year around regardless what you are doing. I never calorie restrict, never stop eating and never gain fat. I stay on a high performance level all year around. There is no secret or genetical advantage. If we eat what we are designed for by nature, we never get fat. As spiders never get fat on flys, and the gorillas never get fat on leaves. If we get fat from any food, probably that is not right for us.

[Mariano]

Believe me, I am no endurance athlete. I bodybuild and do some cardio. My heart beat rate difference between steady state cardio and HIIT is that HIIT get me 40 BPMs more than steady state! I tend to do 30 secs fast, 30 secs slow, etc. and when I begin to fatigue I go 15 fast, 15 slow (mostly because it is easier to read a clock at 30 or 15 secs). It keeps me engaged and you never thought that 15 secs could take so long :o) I also like to pump some light weights or use elastics whilst on the fast portion to accentuate the effort (on a stationary bike)--that really get me going, especially when I do not have much time for cardio. This is a great way to get'er'done very effectively and efficiently.

[Mick Mathews]

I've seen it every year for over 30 years. My weight goes up every winter and it never comes off until my training intensity goes up in the late spring.

[markowe]

Just looking at my totally subjective experience, one year I started base training very late (for me), like January, with a big break from about November. In that time I had put on about 10 kg, and I'll tell you what, it took absolutely MONTHS to get off. I put that down to the failure of low intensity endurance riding to burn it off. It was only when I started really getting into race intensity that it all came off. Tell you what else, in the month it took to lose around 7 kg my performance improved by some 10%, which is also something to think about. I wouldn't have thought a small amount of excess fat would have SUCH a profound effect on my performance.

Prevention is the best cure, though. Whenever I train in continuity throughout winter, whether at high or low intensity, no fat sticks, not a chance.

[Shane William]

There are some popular workout programs in the market such as Insanity and Turbo fire. Does anyone has experiences in these type of programs? Are these really using the theory of interval training?

[PaulRidesBikes]

Late reading this post. My Jan to Feb weight loss plan is, watching what I eat but I give myself some slack at supper time. Lots of veggies, fruits, and nuts. I workout 6 days a week, 6 to 8 hours, mostly aerobic. Half of my time is on the bike, the rest involves swimming, walk/run, strength training. I've lost 5 pounds over 5 weeks. However,almost every bike ride involves 2 to 4 hard efforts due to hills or choosing to do a short interval.

[vetverbranding]

My plan is like everyday, i ride 15 km a day on a bike. I had read on some posts on the internet that bicylcing isn't the option to lose weight...
Everyday i was losing 1,5 kg fat, so at the end of the week, it was 10,5 kg!! And i just eat whatever i like.

So bicycling is also a good option to lose fat.