For about a year I’ve wanted to have metabolic testing done. This is where you wear a tight mask over your mouth and nose that measures the contents of your exhaled breath and gives an idea of what type of fuel you burn under various conditions. Since I’ve had trouble maintaining/losing weight, I was curious to get a better understanding of my metabolism. We recently joined the brand-new LifeTime Fitness in our area. As Founding Members we were entitled to a free health assessment and discounts on various services, including metabolic testing. I chose to have both resting and active metabolic testing done.
On my assign day I was required to fast – no food or water before the test. I arrived at the gym and was brought into a small cubicle. I was fitted with a mask and told to lay quietly in a recliner. No sleeping allowed!
Super attractive, right? I had to stay that way for about 30 minutes. For someone who is addicted to technology, it was pretty boring.
After we collected the resting data, I was brought over to the treadmill. They do the test on the treadmill, elliptical, or stationary bike. I was doing the test to improve my running so the treadmill was an obvious choice for me. I was asked to pick a treadmill setting where I knew I could comfortably run for 30 minutes. Since I do run/walk intervals there wasn’t an obvious answer so I guess. The tester started me at a walk and every 2 minutes increased the speed on the treadmill. I wore the same mask as above. After an 8 minute warm-up I needed to do a 5 minute rest. Then we started the actual test. Every 2 minute she increased the speed while monitoring my heart rate and the content of my exhaled breath. Even when I felt I couldn’t go further, I never truly maxed out my heart rate.
So what information did I get?
The resting metabolism information included my resting metabolism. This is 1174 kcal. Meaning that any day that I lay in bed all day without doing anything, I will burn 1174 calories. In the resting state I am burning 70% carbs and 30% fat. Unfortunately this is not ideal. I should be burning 90% fat and 10% carbs. Hopefully making some changes to my diet will improve this ratio.
The active metabolism helped to establish my heart rate training zones. Zones 1 and 2 are better for fat burning. The line between Zone 3 and 4 establishes the anabolic threshold or the point at which your body stops using oxygen to burn fuel and relies on the body’s glycogen stores. Most training should be done in Zones 1-2.
Based on this data I was given a heart rate-based training plan. I will continue my long run each weekend (which should be done in Zone 2 and, as it turns out, the pace that Galloway has assigned me for long runs appears to be in my Zone 2 heart rate range). During the week I will do one “threshold” run where I do intervals that bring my heart rate into Zone 4. The other run is a base building run done in Zones 1-2.
Interestingly the Threshold run seems to correlate well with my Galloway-assigned speed work and the other run works out to be at long run pace for me. I have my next half marathon in about 3 weeks and we’ll see how well this new training works out on race day. I find heart rate training to be interesting. I’m someone who likes specific purposes for each run so this type of plan works well with my personality. In a few weeks I will re-do my metabolic testing and see if I’ve made positive changes.