I’ve completed a few HIMs over the last 3 years and one Ironman. I’ve used the STRYD Footpod for most of them. But I was never quite sure how my rFTP translated into my target power for running on race day. IE how it translated for running at least a Half Marathon when fatigued from a few hours of previously cycling quite hard.
I used Mr Google and pinged the following question to a few tri coaches who claimed to coach people to run with power. I thought this would be a relatively simple question, albeit with a nuanced answer “My FTP is Xwatts, what should I target in my HIM next month?”
I didn’t get any satisfactory answers.
Let’s face it, if you’ve trained with power it’s kinda useful to know how to race with it.
Similar questions would be:
- “What is my target running power with STRYD for a Half Ironman”
- “What is my target running power with STRYD for an Ironman”
Finally Coach Chris Hague gave me an answer. TA DA. This is Chris (@tribuddha). He even gave me a pretty infogrpahic answer; indeed SEVERAL answers and with some caveats.
Here we go:
Here are the caveats
Opinion
I think that’s a good starter for 10. Chris’ recommendations come from his experience with several athletes.
I would add in a degree of further conservatism if a) you are no longer able to describe yourself as a spring chicken b) Your CP curve drops off a metaphorical cliff after 1 hour of training. Here is a chart from Mark@Golden Cheetah. Golden Cheetah is used by lots of people who should be at least ‘quite good’ and yet we all seem to favour those one hour rides which might, just might, NOT translate to HIM glory by themselves.
Me? I would definitely fit into Chris’s categories of a strong runner and rider yet I would be at the lower end of the target running powers shown with STRYD. HOWEVER if I translate the percentage of FTP instead to the percentage of my CPn (when n is the likely run race duration of the HIM) then 90-92% is spot on.
So in one sense I would say Chris is wrong BUT then Chris would tell me that my training hould have been better-refined by pushing harder over the race durations. And, if I ‘m honest, I’d say *he was probably right*. So it is GREAT advice *IF* you have done the training.
Chris can be contacted via: https://braveheartcanada.com
I was puzzled with the same question before my recent half-IM. I went through a video from stryd Youtube channel on the matter and the formula seemed to be too complicated, so I decided to just use my marathon wattage and call it a day. Worked like a charm, I was within 1 watt of the target. For reference I’m a weak cyclist and slightly slower than the strong runner by classification above.
Crucial question from me: how are you simulating higher wattages? Running faster isn’t really a good answer for me, hills would be hit and miss, and wind is unpredictable and not measurable, are you adding weights/parachutes? Can these devices even detect changes in power using those techniques? What is the difference between drag and weight from a power training perspective? Maybe a friend holding you back with a rope would increase power output? I’m sure the number you get is useful in a Limits PM kinda way, but I’ll say again these devices are not measuring power and I’ve yet to see useful information on HOW to train with power while running aside from a slightly more useful pace figure. But that’s not power.
I’ve never said they are measuring power. I’ve always (hopefully) tried to say they (STRYD) give me an excellent proxy for effort.
I don’t have a parachute 😉
you don’t have to simulate higher wattages in the above scenario of the post. your HIM pace will always be lower than your HM pace. so it’s how much slower/easier you need to run to optimise finish time.
the bike power models that extrapolate longer duration CP from shorter durations are pretty good. more so if you are well trained. there are other issues with cp curve/models for running
WHY don’t you have a parachute? 😉 Considering it pace/effort and not something you’re training does make sense. I’m not sure that message is out there though.