So this morning I took my fourth CardioPoint Assessment test with Meghan. These tests are done periodically to see how well your training has improved your fitness, specifically how the body has responded to exercise. It is a way to measure the efficiency of your heart (how well it is able to circulate oxygen to your muscles), and, how well your body is able to burn "fat" faster at different heart rate "zones" (beats per minute ranges). The more efficient/strong your heart becomes, the less work it has to do (number of beats per minute) to achieve the same results.

The basic idea is that you want to train your body, particularly during Long Slow Runs, to learn how to burn more fat than sugar as you run. The easier the body learns to burn your fat, the faster it can do this, then the calories you are burning during workouts are coming from that source. So glycogen is being replaced with energy from fat cells, and that means you will lose more weight as the fat is being burned off.

When your body burns carbohydrates instead of fat, then you won't be losing weight from fat. In fact, if you are not replacing those carbohydrates with sources like GU, CLIF bloks, Hammer, etc. then the body could actually start converting your 'muscle mass' into energy. Clearly, that is not a good choice.

So for those of us who want to lose weight through exercise (through running), the best approach is to maximize the "fat burn" during those exercises, teaching the body to burn fat instead of carbs to fuel the body. The idea that 'running faster means greater weight loss' is false. What results in greater weight loss is going 'longer/further' at a consistent, maintainable pace that is the most efficient for the body to burn fat for fuel.

Ever notice the "Fat Burn" selection on Treadmills? They are an attempt at setting a pace which keeps your heart rate and speed at levels which encourage 'fat burning' instead of carbohydrate burn. You won't run as fast but you will gain better weight loss results.

And this is where heart zones come into play, and why I do the CardioPoint Assessment every 4-5 months. Training via heart zones is basically all about keeping track of what 'zones' you should be training in so that you get the desired result. Zone 1 and 2 are your fat burning zones where you want to build your fitness base. Zone 3 is your aerobic zone, great for endurance training and fitness. Zone 4 is in your Anaerobic zone, where you are no longer burning fat and you are beyond your Anaerobic Threshold. Zone 5 is your speed zone for short, intense sprints for power.

Long Runs should be primarily in Zone 2, which is usually your most efficient fat burning BPM (Beats per Minute) range. And it is the best way to train your body how to burn fat during your runs for long, consistent distances. This is where you build your fitness base. Now if you are doing Speed Work/Intervals, then you are probably going to be in Zone 3 & 4.

My test this time came out pretty well. I am continuing to improve. My VO2 Peak (Volume of Oxygen my body can absorb in a minute) is now 43.1 (it was 32.3 back last April). This means my body is improving in its ability to transfer and use the oxygen my lungs are bringing in during a run. This puts me in the top 75% of athletes in my age group!

My Zones also changed, in a good direction. My Zone 2 is now in the 141-152 BPM range. My Anaerobic Threshold moved to 163 (the beginning of my Zone 4), and my Zone 5 is now between 173-183. These are decent numbers for me and I am pleased. And as long as I am in Zones 1-3, I am burning fat -- more so in Zones 1 and 2 but even in Zone 3.

The last thing this test monitors is how quickly your heart recovers after being in Zone 4 where you are really working hard. The goal is to drop at least 30 BPM within the first minute of going from hard effort to light effort (like from an incline run to a flat walk). And after 2 minutes, it should drop even further. This is another measurement of heart health/fitness. Of course, there are other factors involved here like weight, age, overall fitness, etc. For me, I only decreased about 15 BPM after 1 minute, but I know my heart rate decreases faster than that when running outside.

If you have a sports watch that supports heart rate zones, you can plug your information into the watch and actually program the watch for specific workouts in specific zones. So if I want to make sure I stay in Zones 1-2 during a Long Run, I can program my Polar RS800CX to warn me if my effort takes outside of that range. And I can report against how well I perform against those zones as it calculates the calories burned throughout the run itself. Awesome stuff!

BTW: The test was done on a Treadmill. I ran about 4/5 of a mile during the test. So after the test and discussing the results with Meghan, I went back on the Treadmill and ran another 5K at a 9:27/mm pace. So as of today, I have run 100 miles in the month of April! W00t!

Next stop: the Illinois Marathon Weekend!