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 wild fire 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 lbs you would burn more calories. As you know a 250 lbs person burns more calories walking than a 200 lbs person.
Walking at 4mph with / without weight
I just went to a calorie calculator online and did a 60 min walk at 4 miles per hour for my weight of 200lbs — I burn 468 calories. With 50lb pack I would weigh 250lbs and I would burn 585 calories for the same pace.
So it looks like you can add in 100–150 calories by adding a 40–50 lb back pack to a 4 mph walk.
Jogging at 5 mph with and without weight
Since walking with a ruck at 4mph is the bare minimum standards for military rucking — here is a good test if you put out a little more. Try 5mph or a 12 min mile with 40lbs. Still not blazing fast but a better indicator of effort with / without a ruck. If you input a 60 min jog at 5 miles per hour for a weight of 200lbs — I burn 768 calories. With 50lb pack I would weigh 250lbs and I would burn 960 calories for the same pace.
So it looks like you can add in 100–200 calories by adding a 40–50 lb back pack 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 lbs, I burned 670 calories “backpacking” and 840 calories burned if I place an extra 50lbs 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 40-50lbs 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 4mph, then you would add 180–225 calories to that number of 450 and get roughly 630 — 675 calories burned an hour with rucking.