This morning, I woke up and didn’t feel my best. I’m not sick, but I’m definitely exhausted after some nights up stressing about various things. Nevertheless, I put my gym clothes on and headed to Orangetheory Fitness for a class. Unfortunately, probably as a result of my exhaustion, the workout ended up feeling a lot harder than I thought it should have been.
Today was “endurance day”, which meant that we were doing just one 26 minute block each of treadmill and rowing/weights. On the treadmill, the incline was set to 3% for the entire time, and we alternated between base pace (for me, 6.5mph) and push pace (8mph) in equal intervals of 1-3 minutes each, with a few one-minute all-outs (10mph) sprinkled in for variety. There were no walk breaks, though, and I found that my base pace wasn’t really great for recovery… or at least not as comfortable as it usually is.
As an aside: I can’t be the only runner out there who is obsessed with the numbers on the treadmill screen while running, right? Even if we are only doing a one or two minute interval, I tend to stare at the display and do all kinds of computations in my head to feel better about how much time/distance I have left. When running on my own for distance, I try to calculate exactly how many minutes/seconds are left if I keep the pace the same, pick it up, slow it down, etc. And when doing short intervals in a class, I’ve decided that starting the interval at 20 seconds is better than, say, 50 seconds. When I start at 20 seconds, that means when I (finally) get to the top of the minute, I don’t have that much longer to run, and it feels a lot more doable. I end up breaking my “how much is left” calculation into “only 20 seconds left till you finish this minute!” and then “now only 20 seconds left till you’re done!” #CrazyRunnerProblems
So anyway, after this morning’s workout, I was telling Adam about how it went, and I explained to him that I was a lot more tired than I felt like I should have been from the effort. That is, we weren’t doing much sprinting, and we weren’t setting the incline at a crazy level (i.e., Sunday’s 90 minute tornado where our instructor had us set the incline to 15% and then sprint for a minute… insane!). Today, I never got to a point where it felt like so much that I needed to drop to a walk, but I also felt like the workout should have been easier than it was. As I told Adam, a 1% incline is supposed to be the equivalent of running on flat ground outside with some wind resistance, so 3% wasn’t that much more.
But that’s where I was wrong. Adam showed me a fascinating post on how the oft-quoted treadmill effort study is often misconstrued, and then I went down a rabbit hole of checking out some sites on my own. In fact, the study says there is no difference in energy between running outside and running on a treadmill at 0% if you are going 8:00/mile or slower… which is normally about my speed). (This long science-y post by Hill Runner explains it all the best, if you’d like details.)
The most helpful thing I found, though, was a chart that attempts to equate running on an incline on the treadmill to running on flat ground. The text at the top contradicts the post about 0% treadmill being slower than 0% outdoors, which is kind of strange since it’s the same source. However, I’d guess that the relative difficulty between each grade would still be about right – so I’ll use it for approximations.
According to the chart, my “base pace” of 9:14/mile at 3% is the equivalent of running 8:23/mile on flat ground. No wonder that was a bit too fast for me to recover – that’s a pretty good clip for me. As for my “push pace” of 8:30/mile, doing that at 3% is the equivalent of running 6:58/mile on flat ground… so the fact that I was kind of tired doing those doesn’t make me feel bad. But meanwhile, I am incredibly proud that I was able to hold my “all-out” of 6:00/mile for 60-90 seconds at a time… that equates to 5:42/mile on flat ground! I do realize that holding it for 90 seconds is nothing like holding it for an entire mile, but that is a lot faster than I would have ever thought I’d be able to sustain even for a short sprint.
I guess there is more than one way for math to make me feel better about what I’m running 🙂