This past Saturday I visited the Bank of America Chicago Marathon Expo at McCormick Place in Chicago. Gatorade Science labs invited me to take on the carb/hydration challenge. After a signed doctor's consent, I filled out the healthy history forms and stepped into the on site science labs.
The researchers had me running on a treadmill for thirty minutes with a breathing apparatus strapped to my head and mouth. My nose was pinched off, and in front of marathon attendees to the expo, I started my pace.
It was a little difficult to get used to at first with the air tubes bouncing from my mouth. The expired air helps them determine not only how many calories I was burning at each stage, but also the type of fuel I was utilizing throughout the run.
Every five minutes they had me increase the speed. My heart rate increased along with it. From a starting heart rate of sub 60, my heart rate went up to 194 in the last five minute stage. This test was similar to a cardio stress test of VO2 max uptake which many doctors recommend for post heart patients and coaches use to train athletes alike.
My results were as expected. As my intensity increased, my fuel from carbs and sugars increased and as those blood sugar levels were being depleted, my body would want to slow down and utilize more fat stores for energy. The good news is that if I deplete my carbs stores with the higher intensities, then during recovery, my body will break down those fat stores to replenish them.
All in all, it was a useful test. The take away is two fold:
- Athletes need to understand the importance of carbohydrates in extended training events like the marathon. Your body can only store so much sugar, so events longer than 30 minutes at high intensities should consider some type of sugar intake.
- Secondly, to burn more fat, work out at high intensities and the "after burn" will utilize those stored fat sources to replenish the sugar post exercise.