Q: “I recently started training with a powermeter (Ergomo) and conducted some tests with varying cadence while maintaining my power output on my triathlon bike (agressive low forward position). I found that my HR was consistently about 10bpm higher when I reached 90rpm+ compared to lower rpm values like 70rpm. This is an unexpected result since my usual cadence is around 90 (perhaps just below) and I can confortably crank it up to 130 before I start bouncing.

How should I interpret this? Should I continue working on higher cadence (I already used powecranks wih a fixed small gear for 2 seasons for this purpose) or should I conclude that my muscle fibre setup lacks the fast fibres to be efficient at 90+? I read Jan Ulrich tried to mimic Lance Armstrong high revs without success. Or does agressive positionning on a bike privilege lower revs. compared to the classical road bike setup? “

A: Coach Patrick: I think you hit the nail on the head in your last sentence: high cadence in aggressive aero positioning is tough. Compare Lance’s TT set up and you’ll see it’s nowhere near as aggro as Jan’s. When you say you can do 130rpms w/out bouncing, I assume you mean sitting up and not in your aggro tri position.

Same thing happenend to me in my powermeter move: I found I could hold higher watts at 80rpms than I could at 90 or 90+ rpms. As I am a bigger guy (6′ 2″ and 185lbs on a good day), I know the aerobic cost of getting my cadence up while aero is high (Note: riding my road set-up in the off-season I have no issues riding 90-100rpms).

As my goal in IM racing is to keep my HR down as much as possible on the bike (so I can crush the run), if I can manage to sustain the lower rpms, with a good wattage, and conserve HR, I am golden. Let’s be clear that my rpms are around 80, and not below. While I have found lower HR values at pushing a lower cadence, I can’t sustain the power output required to ride at, say, 70rpms for 5.5 hours. And I am quite sure a kneecap might pop off.

If you are going to make the move to a lower cadence, you will need to do significant conditioning to prepare your body for this change. The stress on your muscles and the connective tissue in your knees and hips is significantly increased at lower rpms/higher torque. You should consider including lower rpms sets in your weekly training regimen, as well as including some standing low rpms sets as well (say 3 hour ride w/ middle hour as alternating 3 min intervals – 3′ standing low rpms, 3′ seated low rpms). Of course, you should gradually build into this (start w/ 20 mins, then 30 mins, etc.). Back off at any sign of residual knee/hip pain or discomfort…recover…then begin again.

Do the right work and you just might find yourself going faster for minimal effort!  Good luck!