Heart Rate Training: The Final Verdict

Last September, while I was training for Marine Corps Marathon, I knew that I was going to have some unstructured time after the marathon and before I needed to get serious about Ironman training. All of the IM training plans I was considering were based on heart rate zones. I’ve read a bit about heart rate training and how it can effect fat burning, so I got tested. The last test I had was 18 months and many medical treatments ago. The September test showed that my zones had shrunk significantly and my fat burning was very low. My zones were so low that it would have been difficult to train in the zones prescribed by my plan. Do a 2 hour run in zone 2? Heck, I couldn’t run for more than 10 minutes in zone 2 without drifting into zone 3. I would have to take heart rate training seriously. I decided to do all of my Maui Marathon training in zone 2, recover for a few weeks, and get retested. That would give me a full 12 weeks to try to improve my fat burn.

So that’s what I did. Twelve weeks of running slow. Twelve weeks of jogging, walking and whining. Twelve weeks of not being able to run with my friends or feeling bad when they did run with me because I was making them run slow and walk constantly. The worst part was that it was twelve weeks of not knowing whether all of this effort was actually working. I gave up training hard for the Maui Marathon and settled for just finishing. As the twelve weeks went by, heart rate training began to feel more like a gamble than a plan. If it worked, it would have been one of the smarter training decisions I had ever made. If it didn’t, then it would have felt like a big waste of effort.

Heart rate training is one of the best training decisions I have ever made. My fat burning percent improved dramatically. My heart rate zone 1 expanded beyond what I thought would be possible with just three months of training. Last September, my zone 1 ended at a pitiful 92. Now my zone 1 ends at 160. Last time, my zone 2 ended at 129, just high enough for me to jog and walk on and off. Now my zone 2 ends at 168, high enough for me to run for three hours and stay well within zone 2. In every zone, I dramatically increased my calorie burn per minute. Two zones increased by 50% and one zone increased by 100%

Thinking that a higher calorie burn is a good thing is kind of counter-intuitive. You might think that it would be good to exercise at a certain heart rate for a minute with less energy. But think about moving a rock. It takes a certain amount of energy to move a rock. Your body burns fuel, either carbs or fat, and converts that to the energy that your muscles use to move the rock. If you can generate 15 kilojoules of energy in a minute you are going to move the rock faster than if you can only generate 10. Yes, efficiency plays into how well you can push the rock. But you would have to be 50 percent more efficient to push the rock as well with 10 kilojoules as you would with 15. Burning more calories means generating more power and being able to run faster and bike harder.

I started weight lifting in 2005 and since then I’ve had this test done periodically. I had similar test results to this new one back in 2009 shortly after I finished my third marathon and was getting ready to train for a triathlon for the first time. I was running 3 days a week, lifting 2 days a week and resting 2 days. Since then, I have gotten more aggressive about my training, many weeks training 7 days a week and, during the tri season, doing more than one work out on some days. I think over-training and lack of sleep played a role in my poor test results last September. Doing the heart rate training forced my body to adjust and burn fat at low levels of effort. I had thrown my metabolism out of whack with the way I had been training and I have no idea what effect my treatment had. Training in the right zone along with time and rest have done their magic.

Thinking about heart rate training? Here is my advice.

1.  Get a metabolic test done and determine your zones, VO2, fat burn, AT and everything else that goes with it. Think you can figure it out by feel? You can’t. Zone 1 doesn’t nessecarily mean easy effort. The zones are an indication of fuel you are using. Can you tell at any moment how much of your energy is coming from fat and how much from carbohydrates by feel? I don’t think so. Set up a retest after your training period and see what progress you made.

2.  Get used to people telling you that they tried heart rate training, but they just couldn’t tolerate going slow. I can’t count the number of people that told me this. Normally fast people, normally slow people, it didn’t matter. Put your ego aside and stick to the plan. Faster does not mean better and it certainly doesn’t mean smarter. Get used to the idea that not every single workout needs to be hard. My VO2 peak actually went up, as well as my VO2 at threshold percentage. In other words, I actually gained fitness during heart rate training.

3.  Can’t run in zones 1 and 2? Then jog and walk. Row. Bike. Swim. I did all of those things during the first few weeks of  heart rate training until I got to the point that I could jog and finally run in zone 2. I was reading about Ironman training and a coach was answering questions. The question was, What if I can’t run in zone 2? The answer was, and this isn’t an exact quote but pretty close, “I don’t care if you have to drop on the ground and do snow angels to get your heart rate down. Do not go over the target heart rate for the workout.” There were many times when those words rang in my ears and I put my ego aside and I started walking.

4. Best piece of advice that I didn’t take? Cut back on carbs in your diet. When I had my first test, the trainer explained that cutting back on carbs would force by body to burn fat for fuel since carbs would not be readily available. My diet is still a work in progress and I didn’t consciously cut back on carbs. It’s possible that as I started burning more fat and less carbs that I craved them less, but I didn’t keep track of that. As my workouts get longer and I need to fuel up more before my workout, I will rely more on protein shakes and try to avoid a lot of sugar so that I don’t have a lot of carbs in my system at the start of the workout.

The more I read and talk to people interested in metabolic training, the more I learn and find it fascinating. Learning how the body is supposed to work and how training is supposed to effect it is one thing, but putting it into action and trusting that it will work took a leap of faith on my part. I feel like I’ve done what I needed to do to get myself in a good position to start training. Seven more weeks until the official first day of training!