Are You Efficient Under Your Pack? Find Out: Do the 3-Mile Rucking Assessment

Efficiency under load is paramount for a hunter. No matter if you’re a big game hunter packing in and out of the backcountry or a Western upland hunter hauling a vest loaded with water and dog wrangling equipment as you cruise up and down the high-desert mountains. Aerobic capacity and aerobic power are on equal footing with efficiency under load. They are, of course, aspects of work capacity in the general sense. But they are also specific to hunting. You gotta be able to walk long, and you gotta be able to walk fast (at times) and sustain your effort while hauling freight. The 3-Mile Rucking Assessment tests all of these in a simple, measurable, and repeatable way. Here’s how it works.

It begins by plotting out a repeatable course on the flattest ground you have access to. We want flat ground for this test because it eliminates heart rate confounds. As I’ll discuss in just a minute, we want to track your average and max heart rate during the test. Hills and terrain changes add variables into the test that make it difficult to get repeatable heart rate measures. 

Once you have your course plotted, you’ll need your pack loaded with 20% of your body weight. The natural question that follows is why 20% of body weight. It’s the minimum amount of weight from which we can determine efficiency under load. It gives us enough weight to learn what we need to learn without introducing unnecessary stress. Specific to hunting, it’s a bit more than regular day pack weight for most folks, depending on the hunting scenario. For example, my typical day pack that accounts for all possibilities of long days hunting is about 30 pounds. That’s food, water, layers, medical supplies, kill kit, fuel, emergency kit, ammo, and my rifle. Necessary shit, nothing excessive. It’s what most prepared hunters would carry in the wilderness. Now, being about 195 pounds, 20% of my body weight is around 40 pounds. We’re 10 pounds north of the load I need to carry all day long. It's a good, specific bridge between the weight I must sustainably carry all day and the heavier loads of packing in and out. It’s very good to learn how well you do that on flat ground before you get onto terrain.

You’ll also need a chest strap heart rate monitor synced with either a phone app or a watch. Yes, you likely have a fancy watch that tells you that it accurately tracks your heart rate. It does not. Especially when you’re moving fast and your heart rate rises. You need a chest strap for accurate heart rate monitoring. And you need to set your watch to track your distance and time, or you need a phone app that does it. 

Once you’re all set with your course, the load in your pack, your heart rate tracker, and your distance tracker, it’s time to party. You’ll walk the course you set at your fastest sustainable pace. One foot must stay on the ground at all times. Running with your ruck on is a bad idea, besides we’re testing the sustainability of your movement, not how fast you can run with weight on your back. 

As soon as you finish three miles, hit stop on your distance and heart rate trackers. Note the time it took you to complete three miles; note your max heart rate, and note your average heart rate. We want to see hunters finish in 45 minutes or less with an average heart rate in Zone 2. If you hit those numbers, it tells us that you have sufficient aerobic capacity, sufficient aerobic power, and you’re efficient under load. We learn about aerobic capacity and aerobic power from the heart rate numbers. If you sustainably produce enough energy aerobically to move at a 15-minute mile pace while keeping your heart rate average in Zone 2, your capacity and your power are in a good place. That doesn’t mean you can’t, or shouldn’t, improve them. But you’re in a good place. We also know that you’re efficient underload, because you wouldn’t sustainably hold that pace if you weren’t. The synthesis of what we learn is where can you sustain effort and how much does it cost you? 

Here’s the follow-up, what if you don’t hit those numbers? It’s not the end of the world, and you can turn things around relatively quickly. It also doesn’t necessarily mean that the mountain will steal your soul. But it could mean a few things.

First, it might be helpful for you to lean out and improve your body composition. This will improve your relative strength. That will decrease the energy cost of each step you take. You’ll also carry less weight in your pack. You might think, wouldn’t carrying less weight just kind of be cheating? No, it isn’t. Think about the numbers we talked about earlier. Testing at a weight that’s significantly higher than day pack weight doesn’t do anything for you other than make the test harder than it needs to be without learning more from it.

Second, you likely need some time under your pack. You build efficiency under load in a few ways. One, you get relatively stronger with consistent strength training. Two, you walk around with your pack on. Pretty straightforward. Load your pack well by keeping the weight in the middle of your back and tight to your spine. Keep the weight around 20% of your body weight. Then ruck — mostly at a pace that keeps you in Zones 1 and 2 so you build efficiency with your posture, your movement, and your breathing. Third, you do rucking-adjacent exercises such as carries and sled drags. Carries train and reinforce good posture and breathing under load. Sled drags train the legs in a similar way as rucking with a different stress load. Dragging angles load the lower-body a bit more than rucking, carrying over well when it’s time to put the pack back on. But even with all of the relative strength and rucking adjacent work, you must get time under your pack.

Third, if you have been doing a lot of packing work, we’ll say two to three times per week for months, and you still can’t pass the assessment, there are likely other gaps in your fitness other than efficiency under load. That means you likely need to shift your means of aerobic conditioning to better develop your aerobic system. This is where easy running comes in. I’ve seen low and slow running and run/walk intervals do wonders for aerobic development, and specifically improve rucking economy and endurance. One reason is because running, even in aerobic capacity heart rate zones, demands faster energy production than rucking. That increased rate carries over when you strap your ruck back on and go walking. Running also trains your feet and legs to create more stiffness. That means you get more spring out of each step, which saves you energy. Easy running also improves breathing economy, which trains your body to better intake and utilize oxygen. So, if you’re good under load, but can’t seem to move faster, there’s a good chance that if you cut some of your rucking volume and replace it with easy running, these factors will carry over to improve your general conditioning and your specific rucking fitness.

Now that I’ve told you how to improve your rucking, let’s get you a look at a video on how to perform the 3-Mile Rucking Assessment.

Here’s a link to a YouTube video that walks you through the 3-Mile Rucking Assessment:

3-Mile Rucking Assessment

Rucking is a great measure of efficiency under load and great for getting a general sense of a hunter’s aerobic capacity and aerobic power. But we also need a measure that tells us how prepared we are to move efficiently uphill with our pack on.

You just read how to test your efficiency under load.

But mountain fitness isn't one-dimensional.

The Hunter's Field Test also checks your mobility, strength, and uphill endurance --- and gives you standards for each.

Grab it for free at the link below and see if your body is ready for the mountains.

The Hunter's Field Test