A1 and A2

Yesterday I did an A1 fat-burning session and today it was a classic 8×8 min A2 interval session.

So why A1 fat-burning? Three reasons:

Reason #1. To burn fat (da !). Less fat = less weight = more speed. Simple as that (see Jari Palonen’s blog for weight-loss strategies).

Marathon runners have about 5% body fat and body builders come in around 2-3%. I weighed in at 7.3% last month at the Umeå idrottsmedicine lab.

Since fat contains about 7,700 calories per kg, my body is packed with 55,000 ”ready to use” calories, which ought to last for 9 days of nonstop A1 training, assuming a burn rate of 250 calories/hour. Of course, even the best trained athletes can’t burn fat as the ONLY energy source. Among other things, carbs (”small branches”) need to be added to keep the fat (”big logs”) burning … not to mention sleep deprivation, fatigue, and the need for muscle-repairing protein of course….

But the point is even marathon runners have plenty of fat to burn (!) and I have more than enough at 7.3%.

Would be nice if you could just eat some of these … But it’s not that easy.



But fat-burning can be fun. Just keep your heart rate low, take a friend with you, and find a pleasant place to train … The Coronado Beach in my home town is an ideal place.

Reason #2. Teach your body to use fat as fuel. Endurance racing demands that your body is efficient at burning fat (”big logs”) rather than carbs (”small branches”). Your body takes months and years to ”get the message” — it’s not something you teach it a few weeks before a race. I’ve found that eating a paleo diet (stenålderskost) also helps achieve this goal.

Reason #3 Stimulate race day stress on your body. I like to get up in the morning and train 45-60 min without eating breakfast because there are very few carbs left in my system after 9 hours of sleeping. My body must use fat to get through these sessions, but the key is to keep the intensity low. Otherwise your body will burn muscle and you don’t want that (or at least not too much of that).

Long combo sessions (run + bike over 4 hrs) are good to stress your body under low energy levels, but they beat up the body. Endurance sports scientist and expert Dr. Michael Mattson recently suggested that you could achieve the same goal with less damage on the body by training before breakfast. You still get the stress on your body but you recovery faster. Less rest days & more consistent training is key.

Here’s my HR during my fat burning workout. It rose near the end when I got down in the aero bars, but I was still burning mostly fat according my lactate curve. I accidentally turned off my watch for 6 minutes in the middle.


Today I ran 8×8 min intervals. Why A2 ?

Since I’m getting closer to the C2C race, I need to spend time in the ”race pace” zone. I usually avoid this ”no man’s zone” because it doesn’t improve your aerobic capacity (you’re going too hard) and it doesn’t improve your anaerobic capacity (you’re not going hard enough). But I will spend 11 hours in this zone on the 9th of February so I will learn to love it. Here’s what it looked like today …


Easy on the first two then increasing intensity. I tried to hang out around 170ish, which is right where I feel like I’m going hard, but still have something left to give — like driving in 4th gear when you could go to 5th, but you wouldn’t last very long.


That’s your coaching lesson for the day. Train smart – not hard


PS If you believe this article below then more body fat = longer live span. Ok fine. But I’ll give up years 86 to 89 in order to place top 5 in C2C at age 35. Wouldn’t you?



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