Maximize your ability to burn fat as fuel, by Hunter Allen
25 August 2009
Question: I keep reading about how zone 2 training is crucial in base building, but after reading Power Training Levels by Andrew Coggan, and seeing how much more beneficial Zone 3 is to Zone 2, I am wondering if I am wasting valuable training time. My goal is to maximize my body’s ability to burn fat as a primary fuel, so my question is: Would it be more beneficial to train primarily in Zone 3 as opposed to my current plan of training primarily (70% of time) in Zone 2? Thanks!
Answer: If your goal is to maximize your body’s ability to burn fat as a fuel, then I would give you a couple of suggestions. Zone 2 is definitely the fat burning zone in which your body relies most heavily on fat as its primary source of energy. That being said, it doesn’t necessary mean that by spending more time in Zone 2 you will increase that ability. I am not sure exactly why you want to increase your ability to burn more fat, but I can think of two major reasons and for each reason there is a different solution to the problem.
Situation#1: If you are trying to lose weight and burn off excess fat, then you actually need to train more in zone 4 and 5 in order to stimulate your fat burning metabolism. There is a myth out there that staying in the fat burning zone helps you to lose weight. Actually, it just makes sure that you don’t burn carbohydrates as fuel and the intensity stays low. If you want to lose excess body fat, then you have to ’stoke’ the fire so to speak and that means exercising very intensely. By exercising in Zone 4 and 5, then you burn off all your carbohydrates and then in the 4 hours after your workout, you burn a ton of fat as fuel. That’s the key to really losing some excess weight.
Situation #2: If you want to burn fat in order to extend your endurance range in a racing situation, then I would offer a few different suggestions. Many pros that I coach always want to improve their ability to burn fat in races and therefore spare essential glycogen reserves for later in the race when they need them most. This means teaching your body to use fat first and foremost in every workout. One of the ways to do this is to start off every ride early in the morning before breakfast and ride for at least 2 hours before starting to feed. Ride at Zone 2 and 3 for those 2 hours and then your body is forced to burn fat. At the end of 2 hours, start eating some carbs and protein and then finish your ride with intensity and intervals. This will help to teach your body to burn fat at a higher level of exercise intensity, thereby sparing your carbohydrate stores for later.
Hope this helps!
Hunter Allen, co-author of Training and Racing with a Power Meter with Andrew Coggan
14 Responses to “Maximize your ability to burn fat as fuel, by Hunter Allen”
August 25th, 2009 at 4:33 pm
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August 26th, 2009 at 6:42 am
Hunter:
Are there scientific studies that support your suggestions in Situation 2? Once I rode w/o eating first, I was useless and it sucked. Maybe this is an N=1 and it wouldn’t always be like that., I will have to try it out.
August 26th, 2009 at 1:54 pm
I’m with Doug here. For me at least, I can guarantee ‘the knock’ within 60 minutes using this often-attempted method. Intervals to finish ? I’d be lucky TO finish without crashing. However, I’m no pro but sadly there’s certainly enough fat to burn these days.
August 27th, 2009 at 10:04 am
Doug and Mike-
You definitely can make it to two hours. Maybe you need to build up to it first, by going an hour, hour and half and then two hours. It sounds like you both(as most cyclists have) have really trained your bodies to burn carbs first and ignore the fat stores no matter what level of intensity. I used to do a ton of rock climbing and mountaineering(after retiring from pro cycling) and it was amazing that all of these mountaineers had trained their bodies the exact opposite of bike racers. They could go at a solid endurance/tempo pace for not only hours, but days(!) without much food. I was bonking every 3 hours if I wasn’t constantly eating and I had more body fat then they did! I don’t know of any scientific studies, so this one has to be categorized in the ‘folk lore’ category for now. However, I know it works and I have seen people change this with some concerted effort.
Hunter
August 28th, 2009 at 4:42 am
Mr Allen.
And ride 2hs in zone E and then run 1h30 in E, its the same efect?
Gracias.
August 28th, 2009 at 7:16 am
sorry
then interval TH running like 3 x 10min TH
Thanks
August 28th, 2009 at 7:51 am
Hunter:
thanks for follwoing up, with the road racing off season coming up, this would be a good time to try it out. Ive also heard bonk training described, where you ride until you bonk, some have said this screws up your bodies ability to use carbs and it can take days or more to recover from this. If while doing this training, you feel a bonk coming on, should you down come carbs and avoid the bonk? (however, often I have found that by the time you feel like you are bonking its too late and simply eating some carbs does not bring you back to normal)
August 28th, 2009 at 1:22 pm
Thanks for the tips. I seem to always ride and train in the zone 4 and 5 area and wonder why I seem to just come up a bit short at race finish. I never like to ride without eating but it may force me to train more in the lower zones.
August 30th, 2009 at 6:41 pm
Hi Hunter, Doug and Mike,
Situation #2 suggested by Hunter is, indeed, supported by scientific evidence. There are at least 4 papers (listed below) between 1986 and now, stating that:
“Fasting before exercise increases fat utilization and lowers the rate of muscle glycogen depletion.”
However, lactate appearance increases in fasting individuals in the 1st hour of exercise. This may be the cause of your difficulty in exercising without eating. Also, make sure that you really start not too hard during that 1st hour.
I am not a pro, I am an exrecise physiologist and coach, but I can afford for sure 1.5 hour of exercise at least up to zone 3 before breakfast when I run training sessions with my clients early in the morning. I found very useful, always based on reserach studies I know, not to eat during zone 2 long rides (up to 3 hours). You do not bonk, just you have to be in zone 2.
Last but not least. High intensity exercise induced Glycogen-depletion DOES NOT screw your ability to store glycogen, actually it’s the opposite. Plenty scientific evidence on this as well.
I hope this helps and congrats to Hunter for his so well illustrated answer that inspired me in this reply.
Luisa Sullivan
MS Integrative Physiology
Level II USAC Coach
1. J Appl Physiol. 1986 Oct;61(4):1363-8.
Metabolic responses to exercise after fasting.
2. • Influence of fasting on carbohydrate and fat metabolism during rest and exercise in men.
• Knapik JJ, Meredith CN, Jones BH, Suek L, Young VR, Evans WJ.
• US Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760.
3. Department of Exercise Physiology, College of St Scholastica, Duluth, Minnesota, USA.
Influence of a 36-h fast on the central and peripheral components of VO2 during submaximal exercise and peak oxygen uptake.
4. Effect of Ramadan fasting on fuel oxidation during exercise in trained male rugby players.
August 30th, 2009 at 6:46 pm
This all sounds very interesting about the morning ride without food. My understanding from various sources has been that when you go without food, the body burns muscle (along with fat). For this reason, I have tried to avoid exercising or even going through the day on an empty stomach so as not to lose muscle mass. What would your suggestion be regarding this?
August 31st, 2009 at 3:03 pm
Albert,
You have to go for 5-6 hours in starving mood and after all your muscle glycogen storage has been depleted (which occurs after 2 hours of exercie intensity at 75-80% of your VO2max even with no food) in order to start breaking down proteins and muscle mass. What Hunter is proposing is his Situation #2 is only 1.5- 2 hours of ride at zone2-3 intensity, then he said have some food and then do some more intense intervals.
I hope this helps
Luisa Sullivan
September 1st, 2009 at 7:58 am
One last question, the original post says to start off every early morning ride before breakfast, etc. is this something that one would implement as a routine practice? or are there any reccomendations to implement or maintain such a metabolic shift?
November 6th, 2009 at 10:19 am
In situation #2, does this mean no coffee as well?
November 7th, 2009 at 9:51 am
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