Do you burn less calories doing the same exact workout as cardio improves?

mathoma94

For example, I run 5.5 miles a day in 45 minutes Monday-Friday. I do this exact workout every time without any changes but I notice it's gotten much easier as my cardio has improved and I assume my peak/active heart rate is quite a bit lower as well. I'm not breathing as heavy or feel like I'm "pushing myself" as much doing this workout now versus when I first started out. I'm maintaining my weight so that hasn't changed, I'm doing the same length/distance, the same duration, and even the same exact speed/gradient (treadmill guided). Am I burning less calories now than I did when I started out a month ago because my body has adapted and doesn't need to work as hard to run the 5.5 miles?
I hope this question doesn't sound too stupid but thanks for any advice!

dewd2

If weight is the same you should be burning the same. What device are you using to calculate the calories?

lemmie177

This is a really good question, and not stupid at all. Usually, work (calories) is a product of force and distance, so you would theoretically be burning the same amount of calories as long as your weight didn't change.

However, with something like running, where you learn and practice a movement over and over, you'll increase movement/stride efficiency over time as you grow in skill. Since you have less wasted movement, you burn less calories. While this might factor in making it seem easier, perceived difficulty isn't a great indicator for # of burned calories.

thehoss316

I would just get bored running all the time. Then again I'm built like a tree stump.

chelliebabe2000

thehoss316 wrote: »

I would just get bored running all the time. Then again I'm built like a tree stump.

I'm the same build but ive found speed walking and jogging for a few minutes periodically to be a really beneficial way of warming up, building stamina, and focus.
I found the more I hated doing it, the lazier I would become, and gain muscle disproportionately.
I started slowly for 5-10 mind at a time then picked up pace as my cardio improved. I still don't run long at a time, but I run more frequently.
It also helps improve the oxygen saturation in the muscle tissue which allows muscle growth to happen more efficiently.
Food for thought

robertw486

You would burn less calories, but at very small levels, and even that small level would vary with where your cardio base was to begin with. Due to increased efficiency at any given exercise, that accounts for small changes. If you are also increasing your oxygen uptake as you train, that can impact your heart rate. The more efficiently your body supplies oxygen and removes carbon dioxide, the slower your heart has to beat. And though a very small organ, the heart has one of the highest metabolic rates of any organ, using as much energy per pound as the kidneys. The average heart is only a half a percent of so of body weight in a healthy weight person, but can use 7-9 percent of resting energy expenditure.

kcjchang

Yes. Your stroke volume has changed and your heart is able to pump more volume per beat. Net volume supplied to body does not change but the heat can supply that volume by beating less. Your max HR will not change other than decline due to age. Your not breathing as hard because the intensity is not overloading your involuntary ventilation response, getting easier to supply the oxygen demand not necessary increase or decreasing the need. As other have indicated your efficiency and economy probably changed. Efficiency is percentage of the energy used actually produces work. Economy includes efficiency as well as improved form, better shoes, hydration, etc. There are adaptations happening that weight gain/loss cannot reflect.