Is my weight loss math correct?

[thentram]

Good Morning,

I am in the process of developing some new long-term fitness habits after battling with addiction for a number of years. In the past I've made some good gains and losses following this site, but was never able to commit to anything long term (more than a couple months) due to my struggle. I'm just about 3 months clean now and my 1st priority is to lose the weight I gained over the last few years between now and June through diet and cardio, then start lifting in the summer when my schedule allows me to go to the gym (between work and family it won't be a possibility until June).

A number of BMR calculators gave me the following formula:

66+(13.7*weight in kg)+(5*height in cm)-(6.8*age)

Weight = 79.37kg (~175lb)
Height = 175.26cm (5'9")
Age = 31

This gives me 66+(13.7*79.37)+(5*175.26)-(6.8*31) = 1818 calories *1.2 (sedentary desk job) = 2183

My goal between now and June is to lose between 1 and 2lbs a week. I have been running 3 days on and 1 day off, each run burning around 575 (I run just under 5 miles), so my average would be about 430 calories burned a day. In order to meet my goal I would need to run a daily calorie deficit of 500 to 1000. So, with my current cardio at 430 I have been eating between 1600 and 1700 calories per day for an additional 500 to 600 deficit.

Does that all sound right? I know it is possible to overdo it. I am confident in my macros and food choices, I just wanted to make sure I wasn't overdoing cardio or eating too little.

[astigos]

Your calculations are fine and this will work, however you're putting all your success on the cardio which is a gamble at best. What if it's raining/snowing outside and you can't run? What if you sprain your ankle? What if life happens and you can spend the time to run? If you're unable to run then you'll have to eat only about 1300 calories per day which a crazy low figure.

The solution to all this is to start lifting weights to increase your metabolism in order for you to eat more.

[thentram]

Thank you for the response. Yes, I agree that lifting is the way to go, the cardio is a solution for the next 8 weeks as I cannot get to the gym based on my schedule. After June I hope to cut back on the cardio and focus more on lifting, I just wanted to lose as much as I could (safely) between now and then.

[DIL22]

How did you calculate 575 calories burned from the run? In my opinion that seems to be a bit high. Otherwise the math looks correct.

[msm00b]

The math never quite works out. Best advice is to settle on a protocol, do it for a few weeks, reassess, and then apply changes as needed.

[thentram]

How did you calculate 575 calories burned from the run? In my opinion that seems to be a bit high. Otherwise the math looks correct.

I have been using runkeeper.com to plot my route and keep track of my times. I have been mostly running 4.75 miles in 40 mins on a route that contain 2 good sized hills. Runkeeper said this would be just over 600 calories, but I rounded down a bit just to be safe. I have recently upped the route to 5.8 miles over 55 mins.

msm00b - Thank you, that is sound advice. I'll see if I can get access to a scale I trust and try weighing in bi-weekly.