Ask Stew: Calculating How Many More Calories You Burn While Rucking

Here is an interesting question concerning people who like to ruck for exercise as well as to keep them in tactical fighting shape. Whether the enemy is a terrorist in the mountains or a wildfire on a high desert plain, some people ruck for a living. I have always wondered this question as well, especially when rucking is compared to normal walking or running for calorie-burning numbers. Here is the email question:

Stew, As a former 82nd Airborne Division officer/​paratrooper and current firefighter/​paramedic, I love your workouts -- thanks for all you do! I have an app (cardio trainer) that I use to keep track of my mileage when I run or ruck. It also keeps track of calories burned, but obviously it is not the primary reason for my workouts. It is a fun motivator, though.

My question is, do you know of any sort of calorie conversion for ruck marching? The app tells me how many I burned for walking 5 miles (and I realize that is just an estimate, but I assume I burn a lot more calories carrying a 40 pound ruck the same distance). It would just be fun to know how many.

Great question and thanks. I do not know the weighted walk conversions, but I would guess it would be similar to if you weighed an extra 40 pounds, you would burn more calories. As you know, a 250-pound person burns more calories walking than a 200-pound person.

I just went to a calorie calculator online and did a 60-minute walk at 4 mph for my weight of 200 pounds. I burn 468 calories. With a 50-pound pack, I would weigh 250 pounds and burn 585 calories at the same pace.

So it looks like you can add in 100-150 calories by adding a 40- to 50-pound backpack to a 4-mph walk.

Since walking with a ruck at 4 mph is the bare minimum standard for military rucking, here is a good test if you put out a little more. Try 5 mph or a 12-minute mile with 40 pounds. Still not blazing fast but a better indicator of effort with/without a ruck.

If you input a 60-minute jog at 5 mph for a weight of 200 pounds, I burn 768 calories. With a 50-pound pack, I would weigh 250 pounds and burn 960 calories at the same pace.

So it looks like you can add 100-200 calories by adding a 40- to 50-pound backpack to a fast walk/​jog, depending on your weight and pace.

Now there is a calorie-burning standard for backpacking, which is typically a weighted stroll at a much slower pace of 1-2 mph. At my weight of 200 pounds, I burned 670 calories "backpacking" and 840 calories burned if I placed an extra 50 pounds on me. So -- yes, it makes sense that you would burn more calories by either going faster than "backpacking pace," which I would average out at 4-5 mph, as well as when you are carrying even more weight in a ruck.

So a precise answer is tough as this is a bit all over the place. I think a safe calorie estimate for rucking with 40-​​50 pounds is to add 40%-50% to what a walking/jogging calorie burn would be at that pace. So if you are burning 450 calories just walking at 4 mph, then you would add 180-225 calories to that number and get roughly 630-675 calories burned an hour with rucking.

Stew Smith is a former Navy SEAL and fitness author certified as a Strength and Conditioning Specialist (CSCS) with the National Strength and Conditioning Association. Visit his Fitness eBook store if you're looking to start a workout program to create a healthy lifestyle. Send your fitness questions to stew@stewsmith.com.

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