Timex Heart Rate Monitor readings and CC

I bought a Timex Ironman Triathlon Heart Rate Monitor Watch at Big 5 for $50.  I just got back from playing squash and here's end results from the session:

I set a manual HR zone from 125 to 170.

In the Zone 50 minutes

152 average HR

173 peak HR

101 minimum HR

1049 calories burned! But accordig to CC, they only put 921.

I'm 35yo, 203lbs and 5'6".

My calorie daily goal is 1534.  After my work out, the estimated burn meter for the day became 3000. 

My deficit will end up being 1466 calories.  Is this ok?

I also did 1 hour of mountain biking on Saturday and Sunday.  According to the HR monitor, I burned a little over 1000 calories as well.  My deficit for those two days were over 1000 calories also. 

Should I be eating me more or is my deficit safe.

Yes the deficits are just a bit too big. Don't let the deficit sit over 1000 and on the days when you workout as you have been, bring the deficit in to 850 to 750 by eating a bit more.

Also, your heart rate monitor is expected to be more accurate than CC -- CC is creating an average which is not horribly off, but as you have the HRM you can go with that.

The reason you don't want a deficit of more than a 1000 is you are trying to lose weight and want to encourage the body to use the fat stores you have. If the deficit gets too big, the body hunkers down and holds onto the fat stores assuming you have hit a famine and it needs to conserve what it can.

Somewhere between 500-800 as a deficit seems to keep the body happy enough that it will go into the fat stores to make up the energy deficit which is what you are shooting for.

Well, I'm going to play squash today and will probably burn 700 to 1000 calories.  I had an egg mcmuffin to load up on calories for the day.  I know.  I probably could make better choices.   I had a 500 cal deficit yesterday and no exercise. 

I'm actually looking forward to eating a bit more today.

Thanks for the response.

I'm just going to tell you my experience.  I had a timex HRM (don't know exactly the style) and I think it overestimated my calorie burn. 

I use to wear it on the treadmill and it would tell me I burned 500 calories for 3 miles or so, and when weight lifting it would tell me I burned like 800 calories for an hour workout. 

When I switched to a Polar F6 HRM it reporst my weight workouts as being 400-500 calories.  So the Times was overestimating by quite a bit.  The Polar also matches what you get from the estimators on this site and others, so I trust it a lot more.