The Iron Mile is a concept I ran across online. I can’t remember where, so I can’t give credit. However, I have found that it’s a painful, sucky way to spend 20 minutes. It also makes you feel awesome.
Pick up, drag, or pull something heavy for one half-mile. Because you made it half-way you now have to take that weight back to where you started. You can’t just stop, drop the weight, and give up. It forces you to take that weight back.
It’s a great aerobic workout, my heart rate was about 130-135 during my first walk, just under my aerobic threshold. This falls under the category of steady-state cardio, and while most of my SSC is usually 30-40 minutes in length (with a 5K pace and distance), the added weight makes 20 minutes feel like 2 hours.
The relatively short duration makes the Iron Mile a nice little add-on to another workout, rather than a workout by itself. Of course, this is my own opinion. Feel free to experiment and go 2 miles, or 3 as a full workout. As I bring my Iron Mile time down, I may add further distance, change how I carry the weight, or change any number of variables to experiment with the concept and push myself further. For my programming, I plan to add one Iron Mile onto at least one workout a week for the next five weeks, then I’ll add two Iron Miles a week after that – until I am doing three Iron Miles a week.
Now, there has to be a reason for performing the Iron Mile. The main physical purpose for the Iron Mile is to build aerobic capacity under load. This is why adding distance can be beneficial, especially if your time is under 20 minutes. I did my first Iron Mile the other day on a treadmill to accurately measure distance, and it took me just under 18 minutes with an 80lbs GoRuck sandbag on my shoulders. I followed that up the next day by performing an Iron Mile with the same load but outside. This added various inclines/declines along my route, as well as much higher temperatures than in the gym.
Overall my mile ended up being about 90 seconds longer, just over 19 minutes. In my case, it also gave my core and upper back a run for their money, because I had to stabilize the weight for the entire duration. About half-way through I could feel my upper back compressing under the weight of the bag, so I had to shift the weight back and forth slightly from one side to the other to release the tension and pressure.
However, the physical aspects aside, I believe the main purpose of the Iron Mile is to build mental resilience and antifragility to physical stressors.
An 80lbs sandbag on your shoulders for 20 minutes starts to hurt. You want to put it down. Your upper spine begins to compress, squashing your diaphragm just enough to affect your ability to draw a full breath unless you concentrate. It really comes down to just putting one foot in front of the other. You don’t think about the pain in your shoulders, back, or feet. You just keep moving.
I started with an 80lbs sandbag. I probably should have started lighter, but because I’m only doing this once a week I plan to keep the weight at my current load. When I begin doing two-a-weeks, I may change it up and do a tire drag on my second day to give my spine a break. I will also follow up the sandbag Iron Mile with some light upper back foam rolling to decompress my spine, because that, beyond all else is the worst part of this. But I think it’s worth it. If I ever had to stop doing it with a sandbag I’d either lighten the load, or do a tire drag.
So, go get something to carry and get started.