Getting exhausted and its relation to calorie burn.

Fyreside

Looking for some info from the guru's around here. I've been reading anything I can find and searching the forums but haven't found clear information on the specific effects of physical stress or exhaustion. My specific case is a very unfit and heavily overweight person who is working on multiple cardio sessions throughout the day. Most of it feels like about the right amount of exertion to be considered sensible. Say 130-140bpm HR or around 14 on the Borg scale.

What I'd like to know is if there is any specific value in pushing any harder than that from a purely calorie burn point of view. (my heart is in surprisingly good shape)

When I get out on the bike, even a relatively low key ride is just smashing me. And I wonder at the point where I'm breathing like a beached whale, and pedalling very slowly trying to recover a bit.. Am I actually burning many calories or not as much as if I were breathing better with a higher cadence?

Machka9

When I am on the bicycle, I use the formula 100 calories for every 5 km.

If I'm riding slowly, the 5 km takes longer, and in an hour I might only burn 350 cal.

If I'm riding more briskly, the 5 km takes fewer minutes, and in an hour, I could burn 500 cal.

Start with what you can handle, and keep building up.


BTW - calculating calories burned is all estimation ... unless you use a power metre. For me, the estimate above falls pretty close with what MFP says (when I choose a realistic light/low/slow option) and also with what Strava says.

tigerblood6

Maybe you need some energy drink or coffee so it makes your heart pump harder and your veins will be a bit more lighter so you can move faster. Everytime I feel sluggy Ill do that with a combination of loud , angry hiphop music.

Machka9

tigerblood6 wrote: »

Maybe you need some energy drink or coffee so it makes your heart pump harder and your veins will be a bit more lighter so you can move faster. Everytime I feel sluggy Ill do that with a combination of loud , angry hiphop music.

Um ... energy drink or coffee will make your veins lighter???

Fyreside

haha maybe.. . Seriously though. I'm trying to understand the science of whats going on a bit better. Thanks for the replies tho.

leggup

The American Heart Association has guidelines about optimum heart rate: http://www.heart.org/HEARTORG/HealthyLiving/PhysicalActivity/FitnessBasics/Target-Heart-Rates_UCM_434341_Article.jsp#.WdTnSFtSzDA

If it's smashing you to the point where you aren't continuing with your regime, ease back, unless AHA guidelines above are your goal. All calorie burns are an estimate, but generally, being efficient (not breaking a sweat, breathing easily, not struggling) means burning fewer calories. Your current weight has more to do with your calorie burn.

That said, assume the calorie burns are overestimated and try eating back only 50-75% of them if your weight loss stalls.

Machka9

Fyreside wrote: »

haha maybe.. . Seriously though. I'm trying to understand the science of whats going on a bit better. Thanks for the replies tho.

Basically what's going on is that your cardiovascular system is out of shape ... and your leg muscles are probably out of shape too ... and you're working on improving the situation.

Keep at it, it will get better.

Fyreside

@leggup Great link, that pretty much told me what I need to know. As I was saying up top, most of my cardio is probably on point. It feels like a good workout for my fitness levels. And I'd be prepared to keep going with the bike if I thought there was value in pushing through the exhaustion.. But it seems I would do best to consider building up to the riding. Thanks.

@Machka9 I think my legs are in the best shape of any part of me.. Since they are carrying around the rest lol. I just can't get enough oxygen to them at the moment. Thanks heaps for the encouragement. I will keep at it for sure.

NorthCascades

Fyreside wrote: »

haha maybe.. . Seriously though. I'm trying to understand the science of whats going on a bit better. Thanks for the replies tho.

You asked specifically about a bike, so my answer is pretty limited to that context. Fellow cyclist here.

The best and most accurate way to measure bike calories outside a lab is with a power meter. A PM is useful for fitness and science purposes, the calories thing is just a side effect of how it works, by measuring work done. Speed = power * all opposing forces. Opposing forces are things like air resistance, gravity, inertia, the rolling resistance in your tires, etc.

Power = torque * cadence.

That last part is important, even to calories, because 1 kJ on a bike = 1 kCal. When you go up a hill at low cadence you're pushing hard on the pedals, when you do low cadence on flat ground catching your breath there's probably very little. Cadence by itself doesn't tell you enough, simply increasing it won't burn more calories unless you keep the pedaling force constant.

Now, there's the science, at least the quick version. It doesn't really answer your question though. When you feel exhausted, soft pedal for a moment until you catch your breath, then continue. Don't try to fight your body into better shape, work with it to get there. You picked the most fun tire of exercise you can do with your clothes on, enjoy it. What you're doing is making you fitter.

lorrpb

Good job getting started! It's not going to help to exhaust yourself repeatedly throughout the day and it could hurt you. I hope you've been cleared by the doctor for the level of exercise you're doing. If not, please do!
There's such a thing as pacing, which means gradually building up the volume you can over a period of time. It can be challenging when you're just starting, but you can definitely make steady progress. Do what's right for you, not "someone" else or "everyone" else or "people" in general. I know it's hard when so unfit, but it is important to develop habits that will work for the long run.

Djproulx

lorrpb wrote: »

Good job getting started! It's not going to help to exhaust yourself repeatedly throughout the day and it could hurt you. I hope you've been cleared by the doctor for the level of exercise you're doing. If not, please do!
There's such a thing as pacing, which means gradually building up the volume you can over a period of time. It can be challenging when you're just starting, but you can definitely make steady progress. Do what's right for you, not "someone" else or "everyone" else or "people" in general. I know it's hard when so unfit, but it is important to develop habits that will work for the long run.

^^^ This is great advice. OP, if your goal is to pursue fitness and weight loss, then a steady cycling build up at a moderate (or even easy) pace will serve you well in the long term. Think in terms of increased time, not intensity. Just as in running, cycling endurance comes over time. Pushing hard to exhaustion before your body is acclimated to cycling is very uncomfortable and unnecessary in my view. An alternative approach would be to try to "smooth out" the ride by using your gears to keep your effort steady and allowing you to cycle longer.

cwolfman13

Pushing to exhaustion with frequency is not ideal. I'm an avid cycling enthusiast and most of my training is done at a conversational pace...any avid cyclist or runner who is training properly will tell you the same. Not everything is a sufferfest, nor should it be.

Going at a conversational pace will allow you to build up your aerobic capacity and stamina over time...over time you will be able to go further and speed will come on shorter rides.

Actual races and endurance events are exhausting...my day to day training is not.

I'd also be wary of multiple cardio sessions per day...there's not really any reason for that. The only time I've ever really done that was when I was training for a sprint triathlon and by that time I was in a good state of physical fitness...but it was still brutal. A singular 30-60 minutes cardiovascular workout is sufficient outside of more specific training objectives.

Machka9

If cycling is your main thing, there is a cycling challenge thread which might help keep you going.

http://community.myfitnesspal.com/en/discussion/10602580/october-2017-biking-cycling-bicycling-challenge#latest

Fyreside

Thanks for the great info everyone. I'm going to get out today and sus out some sensible routes to help me get my lungs up to speed. Obviously my previous routes were more than I'm ready for.

cwolfman, 30-60 per day is about where I'm at. But I have to break it up into 15-20min workouts just for now. Baby steps I guess

I might be ready for some more challenge next month Machka.

AnnPT77

I don't experience a huge difference in calorie burn per time interval between a reasonably challenging steady-state intensity activity (i e., not dogging it) and higher intensity (but sub-anaerobic threshold (AT)) session, as measured by heart rate monitor. I can't give you precise numbers off the top of my head, but that difference calorically is way smaller than the difference between couch and steady state!

Plus, I can go longer at steady state (by definition! ), for higher total calorie burn, if I have time. Truly high intensity work, i.e., intervals in/above AT, which I've done at times for training purposes, tend to leave me a little more wrung out for daily life after I do them.

Also, you'll hear people claim some kind of "metabolic rev" from EPOC (excess post-exercise oxygen consumption) from high intensity. When you do the math, that's pretty trivial, a handful of calories . . . even more so when you recognize that you can go longer at steady state.

It's harder to say experientially what the caloric impact of intervals is (very high intensity then recovery, repeated), because a heart rate monitor isn't as good at estimating calories for that. I suspect there isn't much bonus vs. steady state, but I don't know about penalty.

Be aware that many elite athletes who need cardiovascular fitness have done a boatload of steady state work in their athletic training, and still do so as elites. So, you're in good company on your current path.

As a regular person initially building base fitness, I'd argue that what you want is a volume/intensity of exercise that challenges you a little, but still feels fun and makes you happy, and leaves you with a good energy level for the other parts of life. On that scale, it sounds like what you're doing now is exactly right.

You'll evaluate your goals and practices and things evolve. Best wishes!

Fyreside

Awesome post thanks @AnnPT77 I went and did some additional reading on the AT and it really puts what I had been feeling into perspective. Steady state is definitely what I'm aiming for at the moment and I've adjusted my cycling route accordingly. As it happens I live at the top of a hill, so it's always a big finish to any ride.. But I've laid out a course that has me just tipping over the AT a few houses before I hit my driveway.

paulwatts747

Machka9 wrote: »

BTW - calculating calories burned is all estimation ... unless you use a power metre. For me, the estimate above falls pretty close with what MFP says (when I choose a realistic light/low/slow option) and also with what Strava says.

When I cycle, I use a Polar heart rate monitor. It gives values that are typically about half to 2/3rds of what MFP estimates. 300-375 per hour is the norm for me if I'm going for it. Generally I average 20-22km/h on a moderately hilly route generally ~40km. This amounts to about 80 calories per 5km at best (my weight is 109kg). Of course you could be a much stronger rider than me.

I also use a Fitbit which gives slightly lower numbers after you take off the maintenance calories for the time concerned, but I'm disillusioned with Fitbit because it gives ridiculously high calorie burns for walking compared to cycling. It also credits me with thousands of steps when I'm riding, even though it correctly identifies the exercise as "Outdoor Bike".

VintageFeline

I feel like it would be more prudent and sensible from an increasing stamina point of view to stick to just one ride per day. Even if that equates to less time spent on the bike, more isn't always better. There's a reason starter running programs are built the way they are, too much too soon is counterproductive and a recipe for injury.

All other notes about calories have been covered!

NorthCascades

Keep in mind that running is a high impact exercise and cycling is no impact unless you crash. It doesn't tear up your joints there way running does.

VintageFeline

NorthCascades wrote: »

Keep in mind that running is a high impact exercise and cycling is no impact unless you crash. It doesn't tear up your joints there way running does.

It's usually about tiredness causing poor form, which I would think could easily apply to cycling too? Granted fewer chances for something to go wrong but minimising that potential is never a bad thing.

jgnatca

My big discovery is that the cardiovascular system adapts to new stresses the fastest, followed by the muscles, and finally the tendons/joints.

You can't rush the adaptation, though I find that the cardio adapts the fastest. It only took a week to adapt to a new pace (keep at a running pace a minute longer than the week before).

However, rest is just as important as the exercise, as you have to give the body time to repair and rebuild.

If you try and rush this process, you could injure yourself and put back progress for months.

NorthCascades

VintageFeline wrote: »

NorthCascades wrote: »

Keep in mind that running is a high impact exercise and cycling is no impact unless you crash. It doesn't tear up your joints there way running does.

It's usually about tiredness causing poor form, which I would think could easily apply to cycling too? Granted fewer chances for something to go wrong but minimising that potential is never a bad thing.

Bikes are kind of unique. When you run, it's very free, but you're much more constrained on a bike. There are three contact points (saddle, pedals, handlebar) and your form is pretty much dictated by how they're arranged. The crank arms keep you turning the pedals over in a circle, always the same size, always in one dimension only. This is why there's so little range of metabolic efficiency among cyclists, because we're all doing almost exactly the same thing. Running economy is a complex thing, but in a way bikes are simpler.

An ill fitting bike can be painful to ride. It won't injure you (unless you crash) but it can cause great soreness. If a bike doesn't fit, this will make itself obvious, then you make it fit.

FatWithFatness

Sounds to me like you're just out of shape and you need to keep at it, your work capacity will increase.