What might be the optimum interval training method?
Working on the details behind the Mid Life Athlete framework I’ve realised that I had neglected my VO2 training and needed to re-introduce some interval training back into my training mix. After starting with some basic flat running intervals of fixed work and rest periods, yesterday I had the pleasure of running up hills on a dark, windy morning. This time the workout switched to ascending ladders; starting short and progressively getting longer over a ‘set’. Undeniably these sessions have a huge benefit but it got me thinking what might be the most optimum method?
As you would expect these days, someone has done some research on it. Flippo Vaccari and colleagues at the University of Udine in Italy has done 2 studies, one on cyclists back in 2020 and another more recently on runners and published this month. Both papers are pretty technical and took me a while to figure out, but here’s the essence of what they found.
If we exercise over a certain critical speed (over our anaerobic threshold) we will eventually hit exhaustion. However, it seems that our anaerobic capacity seems to recharge almost as soon as drop below it. This is what allows us to do intervals. We go hard, deplete our anaerobic capacity, rest and then we are able to go again. In doing intervals we are able to accumulate more time at a high level of physiological stress than if we were to continue with no rest periods. That’s essentially how intervals benefit our us.
What Vaccari and his team were looking at were the anaerobic recharge periods. It seems that the emptier the tank the faster the recharge. They tested 3 different interval workouts - long, short and a descending ladder. The idea with the latter workout is that you start with long intervals while your anaerobic capacity is fairly full, and gradually move to short intervals as it gets depleted, so that you’re always starting your recovery interval in a sufficiently fatigued state.
The results were impressive. Here’s a graph showing the time above 90% of VO2 max. Short intervals are on the left, long intervals on the right and the descending ladder in the middle.
As you can see, the runners spent longer in the zone >90% VO2 max with the descending ladder interval workout which in theory should produce a better outcome. So maybe we have our answer of what might be the optimum interval workout.
The descending ladder workout they used was:
Hard efforts of 3:00, 2:00, 1:00, 0:45, and then 0:30 repeated to exhaustion, with recovery jogs of two-thirds the duration of the previous hard interval.
That is interesting info. As a cyclist, I normally use Trainer Road for indoor workouts. They have a huge database of workouts. I did a quick scan by category and didn’t see anything with descending ladders. I could use a workout creator to make my own, I suppose.
I’ve completed their experimental polarized plans and now trying a rolling race plan with more VO2 Max and threshold work in preparation for some early season gravel races.
As a 70-year old cyclist, those recovery days are more important. I’m actively looking for things to improve my recovery, in addition to simple rest. (Might make a good topic for a podcast.) So far, I’m trying yoga/stretch session on my off day and prioritizing sleep quality by eating earlier (at least 3 hours before bed) and cutting back on alcohol. My Oura ring scores for sleep quality and readiness (including HRV) are fairly dramatically affected by these two changes.