What do you think burns more body fat?

Calorie is a measurement of the energy a body of certain weight expends to travel a certain distance. No. A calorie is a unit of energy. End of story. It has nothing to do with weight or distance.

*Honeeeeeey* Does this calorie make my bum look fat?

This is incorrect. A calorie is the amount of energy needed to raise 1 gram of water 1 degree Celsius. Reference Nicolas Clement. That is true,but a Calorie(capital C) is the energy required to raise 1 Kg of water 1 degree Celcius.Calorie(capital C) is the unit referred to in the nutritional charts for food.

To get back to your original question -- from my own experience, long, low-intensity activity (i.e., aerobic), such as long distance swimming burns more fat. The way I calculate my activity is by my heart rate. I try to keep my heart rate at the "fat burning" level, which is 60 to 70% of my maximum heart rate. For me, based on my age (55), my target fat burning heart rate is 107. The basic formula is 220 minus your age multiplied by 65%. I lost over 30 pounds in 6 months primarily swimming at the aerobic level. I did a test during one month where I added anaerobic workouts (where I raised my heart rate to 136 or higher) in between my 3 weekly swim workouts, and experienced no change in my rate of weight loss.

For example, running vs. walking: traveling three miles, whether you are running it, or walking it, will use up very close to the same amount of calories. This is incorrect. The only time this would be true is when your walking speed and your running speed are about the same.

This is incorrect. The only time this would be true is when your walking speed and your running speed are about the same. Calorie burning is a measurement of the energy a body of certain weight expends to travel a certain distance. Speed is a factor that determins how much time it will take to get from point A to point B, and it's effect on energy expenditure is very significantly smaller then distance or weight. This would be true if you are limiting the workout by time. Going farhter over an hour will cover a longer distance, and also burn more calories - a lot more calories. If you're walking for an hour, you've covered a lot shorter distance, les energy spent, fewer calories burned. If you vary time, and keep the distance fixed, which is the example I made in my earlier post, then calories burned will be within 10-20% of each other, whether you ran or walked it. Except walking it will take you a lot longer. Heer are some articles elaborating on this: www.runningplanet.com/.../running-versus-walking.html www.runnersworld.com/.../burns-calories-time-distance health.msn.com/.../articlepage.aspx

Calorie is a measurement of the energy a body of certain weight expends to travel a certain distance. This is incorrect. A calorie is the amount of energy needed to raise 1 gram of water 1 degree Celsius. Reference Nicolas Clement. Speed is a factor that determins how much time it will take to get from point A to point B, and it's effect on energy expenditure is very significantly smaller then distance or weight. This is incorrect. Energy is related exponentially to the inverse of time and linearly to distance. As speed increases, energy increases much more. As distance increases, energy increases at the same rate. Reference Isaac Newton. Heer are some articles elaborating on this: www.runningplanet.com/.../running-versus-walking.html www.runnersworld.com/.../burns-calories-time-distance health.msn.com/.../articlepage.aspx The first article actually explains that if you walk as fast or faster than you run, you will burn more calories than running over the same distance. Their conclusion is that going faster burns more calories than going slow. The second link isn't an article but a thread in runners world's forum. Article 3: "A hundred calories is a standard estimate for the energy required to move a body a mile by walking or running. A heavier body requires more energy (hence, a greater calorie burn) to move. Yet any size body can move with greater intensity to also burn more calories" Article 3 is an explanation that 100 calories per mile is a rule of thumb. This works for most people because most people aren't going to train that hard or want to do any math.

Since wave drag increases with the cube of velocity and form drag with the square it takes a lot more energy to swim a given distance at a higher velocity. Consider two workouts: 10x100 on 2min at 1min per 100 pace 1000 at 2min per 100 pace The first workout will definitely use more energy even though the two workouts take the same time and cover the same distance. Also think about kicking 1000m versus pulling 1000m, kicking takes much more energy even if you complete the same distance in the same time. Running is a poor analogy because air resistance is a tiny fraction of water resistance and efficiency is much less variable.

No. A calorie is a unit of energy. End of story. It has nothing to do with weight or distance. Yes, I know, however it is the commonly used colloquial meaning of calorie burning that we are talking about here, rather a strict phyisics definition. If we wanted to be strict about physics then we need to start talking about joules rather then burning calories anyway. Here's some information on that, for people that may not know: en.wikipedia.org/.../Joules To backtrack from joules to calories, follow from definition of joules, to definition of "work" en.wikipedia.org/.../Work_(physics) Then one can backtrack o calorie: en.wikipedia.org/.../Calorie Hoever, I highly doubt anyone here had a really burning desire to get that far into physics 101.

Running is a poor analogy because air resistance is a tiny fraction of water resistance and efficiency is much less variable. True. Also, I think drag producing cross seciton has more effect on swimming then the weight does in running. I don't particulary care to try and work it out right now.