Exercise! - Using a HRM as a tool in weight loss

07-22-2008, 03:57 PM
I joined a gym about 7 months ago. I have about 60-80 lbs to lose (after having 3 babies), and I have lost 25 since joining the gym. But I feel like it's coming off very slowly, a little too slowly.

I have a HRM, and I try to keep my HR between 120-160 for 40-100 minutes 4-6 days a week. I also lift weights 3-4 days a week for 10-20 minutes at a time. I take 1-2 group fitness classes each week (usually a core class and a kickboxing). I see a lot of new muscle definition in my legs and arms, so I think my weight training is good. But I'm losing less than 1 lb a week, and I have a large % of my body to lose.

When I have run with frineds, and kept my HR 165-180 for 10-30 minutes, I have experienced "bonking", where I feel like total yuck for the rest of teh day. So I stopped lettign my HR get above 165 for any length of time. I also notice an amonia "smell" in the back of my throat/nose when I hit 155-165. I have heard that it could mean that I am burning muscle/protein.

So I wonder if I am exercising too hard? I'm afraid that if I slow down, and work at eith a lower intensity or less time, that I will not be able to burn enough calories to lose any weight. (I try to burn 500-700 on my HRM each workout) . I eat a non processed whole foods diet, prob 1400-1800 calories per day.

Any advice on where I should be trying to keep my HR for best weigth loss? TIA!

07-22-2008, 04:24 PM
WOW! Keeping your HR at 165-180 seems very high.
You could be gaining muscle, which is good cause it means you'll be burning more fat.

The recommended HR for losing fat is 220 - (your age) X (.75)
and keep it within 10 beats per minute from there.

For example: if you are 20 years old you need to reach a pulse rate of about 150 beats per minute (plus or minus 10 beats) in order to be in the fat burning zone.

Congrats on your progress!

07-22-2008, 04:47 PM
Thanks for the reply. The 165-180 range was when I was runnign with frineds, and I have since learned that I will bonk after that intense of a workout. So now I stay 120-160, but I'm not sure if that is correct (b/c I sense an amonia smell and b/c I am not dropping weight like I think I should)

I am 40, so 220-40 = 180*.75 = 135. So 125-145 should be my range? Maybe I am getting too high when I stay in teh 150's??? That's when I smell teh amonia smell.

I just worry that I will not burn enough calories (to lose 1-2lbs a week) if I stay 125-145.. unless I do 120 min+ or cardio a day.

07-23-2008, 04:03 AM
You should stick to 125-145. The ammonia smell indicates you are burning amino acids as fuel, not fat... which would explain not losing any weight. By going at the slower BPM it gives the body enough time to break down the excess fat to use as fuel. If you're working too hard (which causes a higher BPM) your body breaks down amino acids because it can do so quickly regardless if there is excess amino acids in your bloodstream or if it's taking them from your muscles. Either way it's not good.

Also, you only need to burn 500 calories by exercising and cut 500 calories from your diet to lose 2 lbs a week. With your weight it easy to burn 500 with cardio alone for 60 minutes, and if you do weight lifting for an hour that's another 300 calories.

Here's a link to a site that calculates your activities:
just put www and a dot before it.

Oh if you use fitday to keep track of your calories... they have an exercise tracker there too!

Best of luck to you. Keep us updated.

07-23-2008, 10:46 AM
With the amount of exercising you are doing I would take a good look at how much you are eating. I know it seems strange, but if you are not getting enough food, your body will not let go of the extra weight, it goes into a starvation mode and holds onto it.

Check to make sure you are getting enough to eat to fuel what you are doing exercise-wise. I know that this was my problem when I increased my exercise and started to plateau.