I have a question about calories and how many you should burn in one day. When I say burn, I mean when working out in the gym. I have heard that you should not burn more than 1,000 calories in a day to be safe. I have set a goal, as you can see below in my signature, and I want to make sure it is reasonable. Also, I am trying to figure out how many calories I would have to burn in a day to reach my goals and I want to see if there is a limit on how many calories I should burn in one day. Thanks for your help!

You need a calorie defecit of 3,500 to lose one pound. Experts usually suggest combining calorie reduction with increased activity to achieve this.

My workouts usually burn 400-500 calories. I do them 4 to 5 days a week. Burning more than 1000 calories in a workout seems unwise. You don't want to fall below the required number of calories needed each day for basic metabolic function - which means you'll need to increase your calorie intake on days you workout. It's much easier to perform moderate activity and keep your calorie consumption reduced, but roughly the same each day. I hope that helps.

I've got a similar question! Say that to maintain my current weight, I need to consume 2,500 calories. But I only eat 1,200 calories. Is this the same as saying I've BURNED 1,300 calories? I feel kind of silly asking this because it seems like it should be obvious, but I'm not sure! It would be nice to know this stuff to figure out when I could reach my goals. Thanks in advance for your help!

Excellent question. I'd be curious to know the answer as well

I'm not 100% sure of the answer to that, but the way that I understand it is those 1300 calories would be included in your calorie deficit and say you burned another 500 calories in exercise your deficit for that day would be 1800.

I believe "calories burned" refers to calories you sweat out (so to speak) in activity. If you need 2500 calories but only eat 1200, that is usually referred to as a calorie deficit (in this case a 1300 calorie deficit). If you ALSO exercised and burned 400 calories, now you have a 1700 calorie deficit. I believe.

But I have to say, that sounds pretty low! Too few calories for that exercise... (in my hypothetical example).

Unfortunately when you start eating too few calories, our bodies compensate by lowering our metabolism. So theoretically, if you need 2,500 calories to maintain your current weight and your only eating 1,200 - your body goes into starvation mode - and it learns how to survive on fewer calories. This is also how you lose muscle and you can suffer overall health risks. This is why experts say it is safe to lose between 1 and 2 pounds per week, which means a calorie defecit of 500-1000 calories per day, achieved through decreased consumption and increased activity. Anything more than that puts your healthy in jeopardy and lowers your metabolism - meaning you'll need to eat fewer and fewer calories to see the same level of weight loss.

Good question. I would like to know too. When I go to workout in the morning I do hour long cardio and burns around anywhere between 300-500 cal. And then in the afternoon or evening I do 30-1hr of stair master and burns 566-1000 cal. I don't think its 100% accurate but it least I get really sweaty and feels the workouts. So, I want to know if there is really limit for burning cal a day. I always get really greedy on burning cal during work out and thats why I end up doing another 30 min of stair master. I also do weights, but I don't separate them. I just do it after my afternoon cardio.

I've been a bit greedy about burning cals lately too. Today I've burnt calories in the vacinity of 700 cals. But I'm not restricting my calories to 1200. I'm eating more than that, its too restrictive for my liking.

I you "burn" too many calories doing cardio (over an hour) depending on metabolism food eaten etc, you could actually be burning muscle as a fuel! And we don't want to do that, since muscle "burns" calories to just exist.

To be "safe" you need to aim for a loss of 1-2 lbs a week, that's a TOTAL calorie defecit of 3500 - 7000 kcals a WEEK. So to loose 1lb of fat you need to have a calorie defecit of 500 kcals a day. That means if you burn 1000kcals doing nothing and you burn 1000 kcals in the gym, to get that 500kcal defecit, you'd need to eat 1500kcals.

The number of calories you burn doing nothing (ie just existing) is called your BMR or sometimes your RMR these are calories that you'd burn doing little to no activity. You need to take this into account. Then if you add the number of calories you "burn" exercising (everything counts, eg climbing stairs, walking to get the mail etc) you should aim to eat 500-1000kcals LESS than the total amount of calories in a day.

This is all well and good, BUT BMR/RMR calculators are notoriously innacurate for a lot of the population (they were calibrated using male university students ). Also calorie counters on pieces of exercise equipment are notoriously innacurate too.

So at the end of this ramble I'm going to say... You really have to experiment with what works for you! I know it's not the definite answer some people were seeking, but there is no definite answer! Personally I wouldn't advise doing more than an hour's worth of cardio because of the muscle burning effect. Also if I did more than an hour's worth of cardio I'd either be 1) too tired to do anything else all day and 2) wouldn't have time to do anything else!

I would personally recommend 30-60 mins of cardio 5-6 days a week (depending on what your current fitness levels are) and weight lifting 3 days a week to preserve muscle mass.

Here endeth the lesson. Hope it helps! Any PTs feel free to correct me!

My trainer said to work at a low intensity of cardio for at least an hour a day, at least 5 - 6 days a week and to do some weights 2 x a week. Todays work out was a mixture of cardio (just over an hour) and 45 minutes of pilates. I think (actually I know, cause it hurt so much) that there was definately weight resistance in that work out.

Kathy

Yes, 3,500 Cal=1# Fat burned. ~450 Cal=1# of Muscle. Scarey stuff indeed!

Thanks, its good to know. I should cut down my cardio in order to not lose any muscle. Thanks again!!!

I'm not sure about this, but here's a couple of points I wonder about.

1. I think the fuel your body uses first is whatever is easiest - so, what you've eaten that day. If you haven't had many calories, then it takes what it can get from "stored" calories. So I would think it's logical that as long as you eat enough calories to sustain workouts & cover most of your BMR, you won't be digging into muscle stores, you will gain a little muscle mass, and you will lose weight safely.

2. A lot of athletes burn a LOT of calories, and since they don't have fat to burn (not much, anyway), by this logic they'd be eating up all their muscles. But they don't. Triathletes train like maniacs and can easily burn 3000 calories in a day. I'm sure they also consume a lot of calories, but clearly as long as you give your bod what it needs you can burn an amazing number of calories. The ones I know make sure to give themselves regular calories, even during exercise - one guy takes a bag of dates & nuts along on the exercise bike and just pops one or two from time to time.

When I was on the swim team in high school I probably burned about 2500calories a day. I also ate a ton, but if I cut back a little it was easy to lose weight, and I wasn't losing muscle. (I kept eating a ton after finishing with swimming, which wasn't helpful!!!).

Anyway, my belief is that as long as you keep the calorie deficit for the day in the 500-1000 calorie range, you can safely lose 1-2 pounds a week, no matter how much exercise or eating you do.

cheers,
Sue

The problem with this theory is that triathletes (and other serious cardio type athletes) actually do have far less muscle mass than other types of non cardio athletes - picture the relatively small thighs of the average marathon runner vs. the bulky ones of the average sprinter. My guess - and I have no scientific evidence to support this - is that if you miraculously stripped away 95% of my body fat, I'd look more muscular than most serious marathoners. If I could get my body fat as low as a triathlete I'd probably be willing to give up some muscle to get there but since I never will, I'd rather use a good bit of my gym time doing strength training in order to keep the muscle. I don't think that anyone is saying that "fat chicks" shouldn't do cardio - even significant amounts - just don't go crazy with it assuming that more is always better.