Thursday, June 28, 2007

Blog 002 - intensity of exercise and calories burned

I received an e-mail from a listener of my podcast ( yesterday. He had several questions about exercise and weight loss. The first question was whether the intensity of exercise affected the amount of calories burned? Specifically, he wanted to know if there would be any difference in calories burned if he walked, or jogged, a mile at different speeds? This is a common question and I thought it would be good to include the answer in my blog.

Here is an excerpt of my response:

I think I can best answer that question with some calculations:

Assume, for the math, that we are talking about a man who weighs 322 pounds (146 Kg). He wants to cover a mile every morning.

If he walks at 3 miles per hour (20 min/mile) he will burn 168 calories over the course of the mile in the 20 minutes he is walking.

If he jogs at 5 miles per hour (12 min/mile) he will burn 263 calories over the course of the mile in the 12 min he is jogging.

If he jogs at 5 miles per hour (12 min/mile) for 20 min he will have exercised for the same amount of time that he spent walking, but will have covered a greater distance. He will burn 438 calories.

This example shows that intensity of exercise is related to energy expenditure. I used formulas from the American College of Sports Medicine to perform these calculations. I double-checked, and I'm pretty sure I got the math right.


Wednesday, June 27, 2007

Blog 001 - a new medium

After podcasting for a full year I thought I would add a blog. Why not?

My podcast, Fitness Rocks (, is posted every Saturday and covers recent medical research regarding the relationship between lifestyle habits and health or disease.

This blog will be a venue in which I can address whatever I want to, including fitness and health, but also random thoughts and observations.

I’m retired from medicine because I reached a point at which there was more I disliked about going to work each day than I liked. The technical term for that is “burned-out.” So, to say I am retired is really saying “I’ve gotten lost in this life and I’m trying to find my way again.” I suspect I’m not alone.