If there is anything we learn in childhood, it's that Halloween is when you get to cram your gaping maw with absurd amounts of candy. And, because we haven't quite grown up, we still plan to do that tonight. We're going to eat a pound of candy.
With age, though, comes some awareness that a pound of candy is an unhealthy thing to eat. Enough exercise, theoretically, could burn it back off. But what would you have to do to work your way back to the shape you were in before the Halloween binge?
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To start out, we need some raw numbers so we know what we're working with. We're going to be focusing our efforts on calories, because it's a pretty easy metric to work with. You're putting stored energy into your body-mostly in the form of sugars and fats-and you need to use X amount of energy to burn it off. So we looked at the calorie content for ten of the more popular candies you might find while trick or treating.
- Snickers: 271 calories (2 ounce bar)
- Milky Way: 262 calories (2.05 ounce bar)
- Reese's Peanut Butter Cups: 210 calories (1.6oz for two "cups")
- Mars Bar: 260 calories (1.98 ounce bar)
- Twix: 286 calories (2 ounce package)
- Baby Ruth: 280 calories (2.5 ounce bar)
- Jolly Ranchers Hard Candies: 222 calories (2 ounces)
- Hershey's Kisses: 200 calories (1.5 ounces)
- M&Ms: 240 calories (1.69 ounces)
- Skittles: 250 calories (2.17 ounces)
We then calculated the calories per ounce for each. Surprisingly, M&Ms were the worst, at 142 calories per ounce, where as Jolly Ranchers were the "best" (if you can call it that) at 111. We took the average for all ten, which ended up being 127.8 calories per ounce. Multiply that by 16 and you get 2,044.8 calories per pound of candy. Holy crap, that's a lot of fuel we've got to burn.
Disclaimer. You can't simply say "Doing X for Y minutes will burn Z calories." It just doesn't work that way. The rate at which you burn calories depends on your gender, age, weight, heart rate, VO2 max, muscle-to-fat ratio, and other factors. Vo2 max provides important data about how efficiently your body can utilize oxygen as you exercise, which has a major impact on the amount of calories you burn. The closest you may get to an accurate estimate of calories burned is are theses formulas developed by the Journal of Sports Sciences for energy expenditure. However the study admits that this is likely only 75 percent accurate at best. Most people don't know their VO2 max, so thankfully, there are formulas for with and without. You can find slightly simplified versions here as broken down by gender.
Let's assume that the average Gizmodo reader is a male, age 27, weighing 160 pounds (which will be inputted as 72.6 kilograms). We'll leave VO2 max out for simplicity's sake. So we'll be using the formula:
Caloric Expenditure = (-55.0969 + 0.6309 x heart rate + 0.1988 x weight + 0.2017 x age) x time / 4.184
It'll take some algebra (or a website that'll do it for you), but it's not too tough. Just remember your order of operations (PEMDAS, suckas!). You fill in all of the variables except for the one you want to know. So, to solve for time, you want to put in the amount of calories you want to burn for Caloric Expenditure, what your average heart rate will theoretically be, your weight (in kilograms) and your age.
As you can see, the main point of variation between exercises is heart rate. Let's look at some scenarios for burning off that those 2,044 calories worth of candy.
Say you just wanna walk it off. Your nice fall stroll brings your heart rate up to an average of 97 beats per minute (BPM). I hope you have some comfy shoes because you'll be walking for 3 hours and 17 minutes.
You don't have that much time, so you decide to go for a bike ride and push it a little harder. Your heart rate averages 120 BPM now. You're looking at a 2-hour 18-minute ride now. If you're averaging 12 MPH, that means you'll be traveling about 27.6 miles.
Hit the pool. Not only are you getting a full-body, low-impact workout, your heart rate goes way up to an average of 160 BPM. Nice. You're still looking at 1 hour and 47 minutes of swimming. A fairly decent swimmer swims at approximately 1.5 MPH, which means you're looking at over 2.6 miles of swimming. To put that in perspective, the swim portion of the Ironman is only 2.4 miles.
Okay, so you wan to go all-out and do some high-intensity CrossFit training or some hardcore interval runs. Your heart rate is now averaging 180 BPM which is probably too close to your max (using the 220 – your age formula to calculate maximum heart rate). Even then, you're going to be working it for 1 hour and 29 minutes at that intensity.
Simply put, a person of average fitness can't keep up those intensities for those durations. It's a lot. But here is the good news: you don't have to do it all at once! In fact, you almost certainly shouldn't. Don't risk injury (or worse) by going too hard for too long. Spread it out over the course of a week, and of course, talk to your doctor if you have any reason to worry about your health (even young, fit people have heart attacks). Or, y'know, just don't eat that much candy, then you won't have to work so hard.