The current polar vortex spreading across the Midwest and Northeast is causing runners to wisely seek safety on the treadmill. I recently shared tips on winter running but later realized I have yet to write about why and when to run on a treadmill, largely because I used to hate it, perceiving treadmills to be mind-numbing and a cop-out from running outside.
Born and raised in New York City, I still do everything I can to brave the cold, layer up and run, praying I don't finish the run with less body parts than I started with. The rise of streaming content platforms like Netflix and virtual training apps like Zwift provides some entertainment, but it wasn't until I started teaching treadmill classes that I began to find appreciation. I now incorporate treadmills in my athletes' training and my own while being very intentional on why and when! I'll include a workout for you to try with modifications for duration if you make it to the end.
Treadmills can help you master your pacing, correct your form, and do effective hill and speed training. Over time, I have developed a good sense of knowing the pace I'm running +/- 10 seconds without looking at my Garmin. Those newer to running can benefit from getting a feel for fixed speeds and starting to know your target paces like the back of your hand, which enables you to become a more efficient runner in the long run (pun intended!).
In addition, running in place allows you to analyze and improve your form especially if you can see yourself in mirrors or have someone film your posture, gait, and foot strike - hard to do outside unless you have a personal pacer and coach.
Finally, if you don't have convenient access to hills or a track, treadmill running is a good way to build mental and physical strength with inclines (some with declines or simply add risers) and intervals, using the bright console and moving belt to keep you honest. It's often hard to find hills steeper than 4% grade outside or just the motivation to sprint at an uncomfortable speed.
It's also important to be conscious of the drawbacks. Because the moving treadmill belt pulls your legs back, you use glutes and hamstrings less than you would running on static ground where you propel yourself forward by extending your legs backward without any assistance. As a result, treadmills are more quad dominant and create imbalances in the hamstring-glute function. This is exacerbated for runners who spend most of their days sitting at a desk, shortening and tightening lower leg muscles.
Moreover, relying too much on the tread will not prepare you for the randomness of race day weather and terrain. I've experienced everything from blazing heat to heavy rain, sleet, and headwinds, and I know that practicing running in all conditions will certainly make you a tougher and stronger runner.
And, when traveling, while it's tempting to use a hotel gym's treadmill, one of the many reasons why I run is the chance to explore a new city on foot - case in point, a recent run in Havana, Cuba where I was being drafted by a local half marathon champion (or so he claimed) who later in the run tried to sell me Cuban cigars!
As a result, I recommend limiting the treadmill to specific hill- and speed-work and doing your best to take your run outside as often as possible with safety first. If you need more distraction on the tread, a shameless plug to take a class at Mile High Run Club in New York City, where I combine coaching on form, pacing, and breathing with only the BEST music and a Burning Man inspired light show.
Here is a good comparison report on treadmills, and below is a 60 minute treadmill workout you can try for yourself with modifications to make it 30 or 45 minutes.
L1 = Recovery (50% effort)
L2 = Marathon Pace (65-70% effort)
LL3 = Half Marathon Pace (80% effort)
ML3 = 10K Pace (85% effort)
HL3 = 5K/3K Pace (90% effort)
L4 = 400M Pace (100% effort)
M = minutes, s = seconds
Incline set to 1.0 unless stated otherwise
2M L2 / 90s L1
3M: 2M L2, 1M LL3 / 90s L1
4M: L2 Incline 2.0/3.0/4.0/5.0 / 90s L1
5M: (1M L2, 90s LL3) x 2 / 2M L1
6M: (1M L2, 2M LL3) x 2 / 2M L1
5M: (1M L2, 90s LL3 - ML3) x 2 / 2M L1
4M: L2 Hill 2.0/4.0/2.0/6.0 / 90s L1
3M: 1M LL3, 90s ML3, 30s HL3 / 90s L1
2M: 1M ML3, 1M HL3 / 90s L1
1.5M: 60s L3, 30s L4 / 2M L1
1M: 1M L4
30M option: remove one of the 4M intervals, both the 5M intervals, and the 6M interval
45M option: remove both the 5M intervals