Why do the more you do an exercise, the less calories it burns

Yep, exercising is great for lots of reasons, including burning extra calories. But it can be really hard to nail down how many calories you are burning, and it's really easy to subtly overeat and compensate for the exercise if you aren't logging your food accurately and consistently. If you aren't losing weight, you are better off focusing on your diet as that's where the biggest bang for your buck will probably be!

Most people as they get fitter and stronger gain the ability to burn more calories not less.

That may be offset to a degree in weight bearing exercises as you are moving less mass - but in reality people get faster and go further rather than do the exact same exercise as when they were fatter and less fit.
My main exercise is non-weight bearing (cycling) so my body weight is far less important than my fitness and endurance. My maximal calorie burns for same duration are up about 30% since getting very fit despite weighing 30lbs less.

Strength training calorie burns are in relation to how much weight you move not how much your body weighs - stronger you are the bigger the potential burn.

It's one of the failings of heart rate monitors being used for calorie estimates that people think they are burning less whereas in fact their heart is pumping more efficiently as they get fitter.


Feedback - remember weight loss is primarily driven by diet not exercise.

I measure my calorie use on a bike with a power meter, which gives a maximum error of 5% for calories.

They more time I spend on the bike, the more calories I burn. Very clear relationship. A 4 hour ride always burns more than a 3 hour ride.

The better I get at cycling, the more calories I'm able to burn, and the faster I can burn them.

Those are facts, and anybody can verify them independently.

it would probably be better use of your time to do exercises that were not so time consuming as you say you are spending hours working out. If you normally walk X miles, then you can still go the same distance...but every 5 minutes try to jog for 30 seconds or a minute, etc. You will be done faster and using these intervals will help build up your cardiovascular system.

if the work you are doing doesn't get your heart pumping like it used to then it's time to step it up. If you are on a tredmill or elliptical you need to increase the incline or resistance or speed to get more of a workout. It's no different that needing to lift heavier weights over time.

How much weight have you lost?

A 200 lb woman doing an exercise is going to burn more calories than a 140 lb same height woman doing the same exercise and same intensity.

BlaqueDiamond1989 wrote: »

I greatly appreciate all the feedback that you guys have given. I did not mention my calorie in-take above, but I try to only consume 1,200 to 1,300 calories a day. I do track my food in-take by using MFP, and I track my fitness by using my Apple watch and MFP. MFP has my calory in-take of 1,430 in order for me to get down to my goal weight. Sometimes I am full from just 1,200 calories a day, so I don't eat more than that. I don't want to eat when I'm not hungry, so I don't go by the MFP calory in-take that much.

Is that your net calories or your total calories eaten?

If you're only eating a total of 1200 calories with all that exercise, you may be risking serious health problems.

Are you eating back most of your exercise calories earned?

Here is some reasons that your scale didn't move.
1. If you started to exercise more just recently, it could be just your body retained more fluid and you'll see a drop when your body is used to the new intensity of excercise.
2. You could gained more muscle weight and balanced out the fat loss, have your checked your waist or arm, did your cloth fit better?
3. How accurate is your logging? Try weight your food if you want more accurate data. If you really is consuming 1200 to 1300 a day and didn't eat back any excercise calorie, your should see a very fast weight drop because you have a huge deficit

Azdak wrote: »

You don’t fewer calories as you become more fit or more “efficient”. Your fitness tracker or HRM becomes more inaccurate. Efficiency does occur, but it has only a modest effect and is irrelevant for most people.

Your heart rate and perceived exertion become less at the same workload, but that does not affect calories burned. Calorie burn is determined by the workload, not the effort per se.

And whatever small effect that efficiency does have is easily offset by........just working harder—which you should be able to do because.....you have become more efficient. There is no law, state or federal, that prevents someone from exercising at a higher workload as their fitness level improves.

This whole post, 100% endorsed. I agree with the theory (and @Azdak is way more experienced and knowledgeable than I, regardless ).

And I've seen it in practice.

My rowing machine knows what my work is: The same meters, at the same power, in the same time period = the same work, and the same actual calories required.

My heart rate monitor is not so bright. When I get fitter or stronger, my heart labors less to do the same work, so my HRM thinks I've burned fewer calories doing that same work It's wrong.

Beyond a couple of very accurate posts about it not actually being the fact you burn less the more you do a workout - I'll throw in an idea.

With the amount of workouts you are doing, and if accurate with the amount of calories you are eating - I'll bet the reason it appears you burn less is because your workouts have really started sucking and becoming mediocre.

As others mentioned it appears the sole reason for your workouts is weight loss, rather than the body transformation it should be.

But since you seem to be doing everything to make recovery from workouts suck, it naturally follows the workouts themselves will start being not what they could be, nor what they used to be.
Meaning less calorie burn.

I'll bet your body has also adapted max it can for rest of your day, and despite step/distance goals, probably less active than you think.

While in that state of poor workouts, it doesn't feel like it generally - still feels like giving it your all, still feels hard, still feel tired, ect.

But until you compare it with how it feels not in that state - you'd never realize it.

Considering cardio and lifting has efficiency in form improvements when starting out, that should make it feel easier doing the same intensity/weight, to make it feel the same with proper recovery intensity/weight should be improving. and that initial improvement doesn't even require the body improving and getting stronger yet.

Is your cardio measurable for performance - getting better/faster, ect?
Is the weight in lifting going up from the form and strength improvements?