So your 2 miles into your ruck, and you start to feel a tingling. It’s slight at first, and it starts in between the toes on your left foot. You try to ignore it.
But now it’s mile 2.5, and the tingling has spread from your toes to your whole foot. Everytime your foot strikes, it vibrates like Wile E. Coyote taking earthquake pills. You can’t focus on breathing or adjustments. You can’t really bend your ankle either because the numbness is spreading up as far as your shins. It’s causing your ankle to scrape the ground, and at mile 3 you accidentally clip an uneven part of pavement and nearly eat it. It’s all you can think about, and now it’s starting to hurt. You can feel the tightness in your shins and Achilles, and while your left one is flopping around like a ducks foot, you can feel that familiar, numbing sensation just setting in on your right foot.
By mile 3.5, it’s completely numb. When you strike the ground, you can feel a slight vibration in your shin, but nothing more. You want to ignore it, but now your feet are just flailing about, and you can feel your energy sapping. You can’t go on much longer, and you’re falling behind the group.
My feet used to fall asleep all the time when rucking. Although the distances may not have been the same (maybe you made it 4 miles before the tingly occurred), the process of losing feeling was somewhat similar. It frustrated me so much, especially because this reoccurring problem was the only thing holding me back. My cardio was fine and I could handle the weight of a ruck, but once I felt that sensation coming on, I knew my ruck was just a matter of time before I fell back.
I tried a lot of things, but from my experience, there is usually a single cause, and once you figure that out, you’re golden. Just make sure treat it as quickly as you can; rucking when numb can not only be painful, but it can make the whole training process miserable. You don’t want to ruck if you know you’re just going to fail.
1. Your boots are too tight: If this is your problem, you’re likely also feeling a lot of tightness in the upper part of your laces above the ankle. There are a few solutions, but almost all of them involve lacing differently. You could try skipping a lace near the bottom of your shoe or the top. You might also try tying it off differently. I personally leave my laces fairly loose through the entire boot, then at the top give about a finger width of space between my leg and the knot, that way when my calf expands, the laces have a little room to give. The downside of this is that my boots end up looser than most, leaving me susceptible to blisters, a tradeoff I’ve just learned to deal with.
On the other hand, I have a friend who just graduated Marine OCS who swears his way is better. He prefers to get his laces as tight as possible, really wrench down on them, then leave a lot of space between his knot and leg, that way his laces will loosen more and get to that perfect tightness on his feet throughout the ruck.
2. You’re striking incorrectly: Incorrect striking can be caused by a variety of other issues. The main one is that you don’t have correct form. In rucking, a lot of us like to do what is called the “airborne shuffle,” a strategy where you keep your feet as close to the ground and just shuffle them forward. This works for some, but the problem is that, if you aren’t careful, you end up striking with your whole foot instead of just the front. This causes shock to run up your joints, and because of you’re standing pretty straight, a lot of that shock stays in your feet, causing the joints and muscles to swell a lot. When they swell, your feet butt up against the sides of your boot and lose circulation, hence the falling asleep feeling. In this case, just loosening your boots won’t solve the problem because of that constant impact.
The best way to solve this problem is to change your running form. Make sure to get those back legs up, and strike with the front of your foot.
To facilitate this, you can try using boots that have more elevation in the heel or put inserts into your boots. I wouldn’t recommend going to get a new pair of boots just for this issue because the problem is your form, and getting inserts is a much cheaper fix. If you are in the market for new boots already, you can check out US. Patriot Tactical’s great list.