A month back, I mentioned that I’d been following SEALFIT, an over-the-top approach to CrossFit-esque workout programming targeted at the military special operations crowd, for the past four or five months.

In a lot of ways, it was a great experience. First and foremost, I learned that I could push myself through vastly harder and longer workouts than I would have expected. Several times a week, halfway into a workout, I’d realize there was just no way I could make it to the end. But then I’d put one foot in front of the other, and inch my way through. And, somehow, I managed to finish every single one.

At the same time, the volume was insane, sometimes involving hours a day of workouts that beat me into the ground, one after another. Paired with the stresses and time commitments of real life, it proved to be too much. I got sick, and then got sick again. My resting pulse climbed and my heart rate variability plummeted. I had clearly veered deep into overtraining territory.

So, a few weeks ago, I moved laterally to try out the programming from Power Speed Endurance (née CrossFit Endurance). While it’s similarly biased towards running (and therefore in line with my 2016 goal to become a less terrible runner), and still includes two-a-day workouts twice a week, it also follows sensible progressions, includes a lot of pre-hab and mobility work, and generally seems like something you could do for an extended period of time without a death-wish.

In parallel, I’ve been writing a bunch of programming through Composite, and at some point it seems inevitable that I’ll circle around to eat my dog food. But, for the moment, I’m enjoying testing out another fitness guru’s best thinking. If you’re looking for some smart, challenging workouts (and especially if you’re a runner, cyclist, or triathlete), it’s worth checking out.