An uphill battle

Climbing is, for a lot of us, the epitome of what cycling is: from getting a PB up your local climbing segment, to sportives across mountain ranges, to watching the likes of Pogačar dance up them at a sickening pace. There’s something very different about going full gas up a climb to going full gas on the flat; it feels like a different challenge and sometimes quite a bit harder. Is it because of the fact you get less speed for the same effort and the psychological effect that has? Is it the constant force of gravity always putting up a relentless fight? Or are there other factors that contribute to climbing feeling harder than being on the flats?

Having personally got a KICKR climb for training during bad weather, I was curious as, when the gradient was set at a higher level, the same power levels felt harder than when the bike was set to the flats. I decided to do my undergraduate dissertation on investigating the effects of simulated gradients on muscle activation.

6 participants cycled at 75% of MAP for 2 minutes at gradients of 0, 7, 14 and 20% incline. During this test, the EMG (electromyography) levels in a number of leg muscles was measured to determine if certain muscles worked more or less on different gradients. The results showed that there was a statistically significant increase in muscle activity in the gastrocnemius medialis (GM) and bicep femoris (BF), with a significant decrease of activity in the vastus medialis (VM). There were also changes in muscle activity in other muscles that, although were not deemed statistically significant, do present a practical significance given the percentages involved. The reason for these changes could be due to several factors. Firstly, when climbing up steeper gradients, we tend to close our hip angle so as to keep weight distributed evenly over both the front and rear wheels. Additionally, as the gradient increases, saddle angle changes and can require some muscular effort to maintain position.

So what does this mean for us? Based on the results of this study, it can be suggested that training on gradients regularly could improve performance on them. Although power levels over given periods of time can be improved from training on the flats or on the turbo with no gradient, training on a gradient can help significantly with rate of perceived exertion. There’s a good reason that, even after plenty of time spent on the turbo at higher intensities, going out on the roads and hitting the climbs can feel that bit harder. It’s because we potentially haven’t been using the same muscles in the same way, so introducing that new stress does feel like more.

The takeaway: it looks like there are genuine benefits to training on gradients. You can train on gradients by either riding them outdoors, or using an indoor gradient simulator.

(For anyone interested and fancies a longer read, here’s the full dissertation study SP6024 Independent Project (Science) Ass001 - Andy Turner S1300505.pdf - Google Drive)


I’d sure love to read the complete paper

I can email that over if you’d like. I can’t add it as an attachment on here unfortunately

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sent pm

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This is great stuff.
I love my Climb for precisely this reason. I also find a rocker plate is “beneficial” for training too for similar reasons, it lowers your ability to hit 4DP metrics very slightly (only slightly), but makes for more realistic training as you’re using more muscles to control the bike as well as just the power, much like you do outdoors.

It’s also another argument as to why elevation climbed should not be included as a metric in virtual rides, at least without a system simulating the gradient on the physical bike, because you simply haven’t done the same work as someone who has actually been cycling uphill…


As would I.

If you’re happy for it to be “published” online, then something like Google Docs would allow you to upload and share it via link for people to read.


Good idea, I’ve added a link!


Plus it makes indoor training more fun and waaaay more engaging. 14/10 would recommend :slight_smile:


Link below to my “@CPT_A needs a Kickr Climb” gofundme…



Worth it. Maybe you could sell a bike?

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Roger, tough call that. My goal is to get a Climb for this upcoming winter in the cave.

I totally agree with this, just that I find the opposite - I can (un)comfortably maintain a high heart rate going up a climb, but struggle to push myself that hard on the flats. I don’t have a power meter, so don’t have an absolute reference, just HR and RPE.

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This is why I really like training on rollers - it’s as close to the outside riding experience as possible, with the exception of the gradient aspect. I’d love to be able to add a CLIMB to the setup, but suspect I might fall off the back of the rollers!


Love my Kreitlers, but dear GOD! :flushed:

The thought of adding a CLIMB to rollers didn’t last very long, don’t worry!

Nice work! I keep telling folks it’s really difficult to simulate climbs without incline on the indoor trainer or kickr bike . Now just need to move to Pyrenees or Alps! Did you get perceived exertion at 75% FTP ? Always seems harder uphill ! And did test subjects keep same rpm?

Hey way9e0,

It could potentially be that when climbing your HR is going higher due to some muscles being more active, therefore requiring more oxygen, hence the increase in HR for a similar RPE. You might find that the power is the same for on the flats and the climbs, but the RPE and HR are what changes

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75% of MAP, but yes RPE was monitored but there was no statistical difference found. Perception was that with the gradient increasing it felt a little odd and maybe a bit harder, but with the randomised order of the gradients tested, the first one often felt the hardest for most of the participants. A bit like they didn’t feel quite warmed up as there wasn’t a progressive ramp protocol in the warm up

RPM varied from participant to participant (self selected), but between gradients was maintained at preferred ±2rpm

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I’ve always found the flats harder psychologically than climbs because while climbing, you’re conquering a finite thing AND you’re banking potential energy for a descent. Meanwhile, the air you’re plowing through on the flats is happy to absorb every Watt you make, indefinitely, increasing as the square of speed(ish), and you won’t even significantly warm the air for all your energy output…