Monday, April 9, 2007

Donating my body to science: a 3-part series

PART 1. This week, we're conducting our last experiment of the semester in Assessment of Physiological Function. I have previously referred to this class as "the monster 3-credit-hour laboratory class." Despite the fact that this class was time-consuming, it wasn't as bad as I initially though it would be, and I have enjoyed working with my classmates on the experiments.

So anyway, in this last experiment, we're looking at the effect of exercise and cold exposure on the stress hormone cortisol. We're doing this in 3 trials; 1 trial with just exercise, 1 trial with just cold exposure, and 1 trial with both exercise and cold exposure. For this lab, I am both the subject and the co-lab director. As the latter, I work with my other co-director classmate to design the lab, work out all the logistics, assign jobs to our other classmates, and compile all the data. As the former, let me tell you what I did today.

So today's trials was the exercise-only trial. I did a 30-minute submaximal exercise bout using an arm crank ergometer (think of taking a stationary bike and just having one wheel with the pedals, which you'd turn with your hands instead of your feet). I had to do the exercise at a high enough intensity to theoretically elicit a cortisol response, but not so high that I couldn't complete the exercise bout. We were shooting for an intensity of about 50% of heart rate max using the Karvonen formula, which comes out to an exercising heart rate of about 130 beats per minute for me. In addition to the 30-minute exercise, I gave blood and saliva samples at 3 time points: before and immediately after exercise, and then 30 minutes into recovery. We'll analyze my fluids later in the week in order to measure the cortisol response. All in all, the session went quite well today, which me and the other co-lab director are pleased about.

Our next session is on Wednesday, where I will be performing the cold exposure only trial. Stay tuned for more exciting details!

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