Sweet Spot Training for Cycling, What It Is and When It Works

James. This is the WattPlan Podcast, and I'm James. Family, work, building WattPlan, the occasional podium when the right people stay at home, and a sports science reading habit that's frankly out of control. This week, the time-crunched rider's favourite. Sweet spot promises threshold gains without the threshold misery, so is it actually worth it? Lyra's our AI research voice, and every study she mentions is linked in the show notes.

Lyra. Worth it, as long as you know what it is. Sweet spot is riding at 88 to 94 percent of your FTP, just under the power you could hold for about an hour. It's a useful tool, not a magic one. In WattPlan it's the hard session of the early weeks, one or two a week with easy riding around it, and never two hard days back to back.

James. Put a number on it for me. What does that look like for an actual rider?

Lyra. For a rider with an FTP of 250 watts, sweet spot is about 220 to 235 watts. It's hard but controlled. You can talk, but you wouldn't choose to.

James. And somebody new to this, with no power meter at all? They've got no watts to aim at.

Lyra. Then the talk test is the target. Ride it by feel in the workout player and it shows as a six out of ten, a few words at a time. If you can chat, it's too easy, and if you can't get a word out, back off. If you're new to structured training, this is your one hard ride a week, and that's how WattPlan plans a beginner all the way through, whatever their hours. The other rides stay genuinely easy.

James. And why does it work? What's actually going on in the legs?

Lyra. Intensity and duration trade off. Sweet spot is hard enough to ask a lot of your aerobic system, and easy enough that you can stay there for long blocks, fifteen or twenty minutes at a time. So you pile up a lot of work at a meaningful intensity in a session that fits an evening. That's the coaching logic, anyway. The trial evidence is thinner than its popularity suggests.

James. Thinner? It's on every forum going. Everyone I ride with swears by it.

Lyra. It earned its reputation in coaching practice rather than in trials. We looked at two studies for this, and both tested something close to it, a week heavy on threshold-level riding, against a polarised week, which is mostly easy with a little very hard and almost nothing in between. Neither went sweet spot's way.

James. Go on then. Break it to me.

Lyra. Gently. The first is Craig Neal and colleagues, in the Journal of Applied Physiology. Twelve male cyclists did two six week blocks in random order, with four weeks off in between. The polarised block was about six and a half hours a week, mostly easy. The threshold block was an hour longer, with nearly half the time in the middle. Both improved. Polarised improved more. [2]

James. More as in a bit more, or more as in embarrassing?

Lyra. Closer to embarrassing. The biggest gap was in how long they could last at a very hard effort. That went up 85 percent after the polarised block, against 37 after threshold. Peak power and lactate threshold both rose well over twice as much, too. And polarised did it on about an hour a week less riding.

James. Ouch. And the second?

Lyra. Thomas Stöggl and Billy Sperlich, 2014, in Frontiers in Physiology. Forty-eight well-trained runners, cyclists, triathletes and cross-country skiers, in four groups for nine weeks. Polarised gave the biggest gain in VO2peak, the most oxygen they could use, up by nearly twelve percent. The threshold group got no further improvement in the endurance measures, apart from slightly better economy. [1]

James. Okay, here's my problem. If threshold-heavy training lost both trials, surely WattPlan shouldn't be putting sweet spot in my plan at all?

Lyra. Look at what lost, though. In Neal's study, the threshold group spent nearly half its time in the middle, week after week. A WattPlan week has at most two hard days, and everything else is mostly easy riding or rest. Nobody tested a mostly easy week with one or two sweet spot sessions against a polarised one. So the trials warn against making the middle the whole week. They can't tell us about one session in it.

James. But polarised sounds lovely if you've got fifteen hours. I've got five, and a job.

Lyra. And that's the honest gap. These were trained riders over six to nine weeks, and none of it tells you how sweet spot works for a rider with five hours and a job. What the trials do show is which week lost, the one that lived in the middle.

James. So it's not sweet spot that's the problem. It's sweet spot every day.

Lyra. Or, more often, riding every easy day at nearly sweet spot because it feels productive. That's the grey zone people drift into by accident.

James. Then how does it fit across a whole plan? Does it just sit there every week?

Lyra. No, it moves. In the base phase, the hard days are sweet spot. In build and peak, threshold and VO2max work take over more of the hard days, how much depending on your goal. And a recovery week has no sweet spot at all. Every ride is easy.

James. And the classic two by twenty? I'd be amazed if that's not in there.

Lyra. It is, as Sweet Spot two by twenty, Power Waves. Two continuous twenty minute blocks, with the power shifting a little between 88 and 93 percent to keep your head in it. If you train with power, ride the targets as written, because the waves already move you around inside the range. The last few minutes of each block should take focus, not desperation.

James. And if they do feel like desperation?

Lyra. Then either your FTP is set too high or you're carrying fatigue. Either way, take the targets down five percent at a time and finish the session, rather than abandoning it halfway.

James. What about people who race? I'd have thought they'd be the ones doing loads of this.

Lyra. If you race, sweet spot is groundwork, not the finished article. As a road race plan moves into build and peak, threshold and VO2max take more of the hard days, because they're closer to what racing asks. For a sportive, a gran fondo or a gravel event, WattPlan keeps sweet spot in every week of build and peak if you've two hard days, and every other week if you've one. Later in the plan, your long ride picks up tempo blocks as well.

James. And where do the studies run out?

Lyra. Pretty quickly. Both trials were short, six and nine weeks. Neal's riders were twelve men, and Stöggl's group mixed four sports. Neither tested sweet spot as a coach would use it, one or two sessions in a mostly easy week. So we're reasoning from the pattern, not from a trial built for you.

James. Give me something for this week, then.

Lyra. Work out your sweet spot range from a current FTP, 88 to 94 percent, and write it down. Ride your next sweet spot session as written, and if a block is beyond you, tap the minus button in the player, which takes five percent off, rather than stopping. Then look back at last week for any easy ride that drifted up towards sweet spot, and ride that one properly easy next time.

James. Numbers on a sticky note, minus button before I give up, and my Thursday spin stays a spin. The bit I'd have got wrong is the easy days, not the hard one.

Lyra. One evening in the middle is a tool. A whole week in the middle is what lost.

Lyra. The full article and every study we mentioned are on the WattPlan blog, linked in the show notes. And if you've enjoyed this, follow the WattPlan Podcast wherever you're listening, so you don't miss the next one.

James. And if you want a plan built around the time you've actually got, get WattPlan on the App Store or Google Play. Thanks for listening.

Voices produced with ElevenLabs. James's voice is a clone of his own, Lyra is an AI voice, and James reviews every episode.