This week’s question comes in from Brian Davis, a Wisconsin native who races road and CX, who also hosts his own YouTube channel, Brian Davis Races. Check it out here
Question: “Is it better to do fewer intervals at 100% of the prescribed power, or more intervals at a lower percentage of the prescribed power?”
For example, let’s say you have 4×8 minute sweetspot intervals at 300 Watts today. You start the ride and you feel awful. Your legs are dead, your lungs already hurt, and you haven’t even broken 200 W yet. You’re absolutely dreading these intervals.
So is it better to do 2×8 minutes at 300 W, or 4×8 minutes at 270 W?
Answer: This is an interesting question, with a simple answer but some caveats. Nine times out of ten, it is better to dial back the intensity. The other 10% of the time, you need to do both; stop riding hard, go home and rest.
[0.1% of the time, if you’re an elite racer in the midst of a huge training block, you need to push yourself as hard as you can in order to hit that power goal, then limp home at 14 mph and sit on the floor in the shower]
It depends on the goal of the interval set. If the goal is spend time at sweetspot (roughly sub-threshold; ‘uncomfortable but sustainable’), then you need to dial back the intensity. If it feels like you’re going all-out, you’re not doing sweetspot intervals anymore; sweetspot should not feel like an all-out effort. In that case, dial back the intensity, chop off some Watts, and spend the prescribed amount of time at what feels like sweetspot.
Note: When in doubt, ride on feel. You should know what easy, sweetspot, threshold, and all-out feels like. If you don’t, then this is something you need to practice. Without going on too much of a tangent here (maybe this will turn into another blog…), I think there are too many people nowadays that rely solely on their power meter data. Without staring at their power meter, they would be completely lost pacing a time trial, riding in a breakaway, or do long climbing repeats. Power-based training is the best way to improve your physiological fitness, but it also takes guts, instinct, and riding on feel to win a bike race.
If the prescribed intervals are close to all-out (threshold to VO2 Max), and you can’t hit the prescribed power goal, you need to dial back the intensity. You’re digging your own grave by pushing yourself to the brink of collapse, chasing an unattainable power goal. The longer you spend at maximal effort, the deeper that hole becomes.
When dialing back the intensity, start by chopping off 10% of the original power goal (e.g. instead of shooting for 300 W, aim for 270 W). Do one full interval at that intensity, and then see how you feel. If you’re feeling better (maybe your legs just needed to warm-up), increase the wattage by 10-20 for the next interval. If you’re still not feeling great, keep the intensity where it’s at, and feel proud that you’re still putting in work, even when you’re feeling tired and fatigued.
If you feel like crap at the start of the ride, and 90 seconds into the first interval you don’t feel any better, turn around and roll home easy. There’s no point in pushing your body when something is clearly wrong. With that said, there’s a difference between feeling a little fatigued, and feeling exhausted. It’s important listen to your body, so that you know when to push a little extra, and when to come home and go to bed early.
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Thanks to Brain Davis for the question, this one really made me think.