Just figured out exactly why I stopped losing weight.

I was not eating ANYWHERE near enough. My diary may say otherwise, but I just bought myself a gift - a HRM - and even though everyone says MFP gives too many cals burned my hrm said I burned 250 cals in just my 15 min weights session so no wonder it stopped as i've been saying my whole session has been the same amount of cals i burn in 15 mins!!

gonna see what happens when i start eating more

250 cals burned in a 15 min session with weights?

HRM= Heart Rate Monitor

Glad you figured it out. Someone told me a long time ago if you are not eating enough, then your body kicks into survival mode and you won't lose the weight. I need to invest in a HRM. I already use a pedometer for motivation. I think a HRM would be a great asset as well. There are so many out there and every time I start to look at them I get completely overwhelmed. I just need to do a little research.

Oh right thats what a hrm is :-) i feel kind of stupid now lol

My HRM gives me about double the reading that My Fitness Pal says so I normally go with My Fitness Pal.

On the other side, I've found that MFP overestimates the calorie burn of my runs (based on my Garmin calorie readings.)

You are using big weights and are unfit? This sounds like a disaster waiting to happen. Do you have help at the gym? Heart rate monitors are notorious for giving high reads. I would look at your diet first.

These weights have all been approved by my PT to use. P.S i'm not REALLY unfit (i just still see myself as that), and i have worked my way up. i think it is just cos i weigh so much that i burn so many. i dunno

I ask again, what kind of HRM did you get? Even weighing a lot, that is a LOT of calories in that amount of time, especially for lifting.

I discovered this same thing after I got my Body Bugg. I burn, on average, 3000 calories per day.I'm glad you were able to figure it out!

I workout with the Garmin Forerunner 210. The calorie output from my HRM is actually lower than MFP. Everyone's metabolism is different and is constantly changing if you're dieting/working out. It could be an accurate read, but double check that you set up your HRM with your info correctly. I agree with some of the folks on here in that 250 calories for 15mins of weights does sound high, but if you've already put on some muscle...maybe it's correct. All that being said, you're definitely on to something if think that you're not eating enough! It can prohibit weight loss.

Good luck!

Sorry to break it to you, but you're not getting the burn the HRM records during weight training.

The calorie calculation on HRMs is based on cardio and is not accurate for weight lifting. So you will get an elevated heart rate lifting heavy that the HRM "sees" as a high burn, but that is not the case. In this case you might be better off sticking with MFP's estimates.

There's a great explanation here:
http://www.sparkpeople.com/community/ask_the_experts.asp?q=75

I have a Suunto hrm and love it! I feel like the burns are quite acurate but have set it to meet my body's needs. I burn a TON of calories in a circuit session with cardio intervals also. Sometimes MFP underestimates the caloric burn so often times I don't even put my exercise in my log. Id rather just track my calories on MFP and my exercise logs at home. If you're considering getting a hrm...do it!

Gonna have to go with dieseljay on this one. Back in the day of body building, most don't do any extra cardio because they get all they need from lift weights. Not saying this is the best for your heart, but calorie burn is amazing!

But again, you will either see results or you won't. Be your own judge! (and post us the results!). Good Luck!

I'm no expert in exercise but i have a background in science. From the reading I've done about HRMs, the comment by BerryH sounds correct.

The only thing a HRM actually MEASURES is your heart rate. In principle, you could do the same with a stopwatch and a stethoscope. Once your heartrate is known, its still a huge guess as to what's going onside your body.

When people do aerobic exercise, the number of calories they are burning is related to their heartrate in a (somewhat) predictable manner. So if in fact you ARE doing aerobic exercise (and your heartrate is high enough) then it possible to make a pretty good guess how many calories you are burning by comparing your heartrate to a table based on averages of other people of the same age, gender, weight, etc. In this particular circumstance a HRM gives a reasonably useful result.

But many other things can affect your heartrate. Weight training, a scary movie, a good cup of coffee, a loud bang, a heart valve defect, those three little words, and so on. If any one of these "other things" raises your heart rate, there is no magic inside that electronic gizmo that can peer into the detailed biochemistry going on in your body. The only thing it can do is ASSUME your heart is beating faster due to aerobic exercise, compare your heartrate to its internal table, and display the result. Sure there is a number, but it is based on completely invalid assumptions.

Of course you burn calories while weight training. But how many ? From the reading I've done, its a very hard thing to predict. Different people train with weights differently, and their bodies (heart rates) respond in ways which are much less regular than with aerobic exercise. So the number displayed on a HRM is more of a wild guess than a precision measurement. I would guess that the closer your routine is to cardio (lower weights, higher reps, no idle resting between sets, ...) the more accurate the number is.