GTN Does Science! - How Does A Cycle Leg Affect Our Running?

Time for an experiment! Running after a cycle leg doesn’t feel quite right, you feel uncoordinated, your legs feel like jelly and you think your form has gone out the window! But is this all in our head or does cycling really change our running? We find out using ourselves as the guinea pigs!
0:00 - Intro
1:19 - The experiment
3:52 - The results
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[@christianwirth6965]

Just a side note: Asking for a Like more at the beginning of the video as done here and more often this year has led to me much more frequently remembering to actually give the video a like, so for me this works! Great Vid as always! :) Cheers!

[@SimoneChiaretta]

Interesting to see that power went down for Mark and up for Heather, even with more or less the same drop in pace.

[@atlosass]

Really interesting! Love to see more of the "science" side of tri

[@gtn]

We would love to get a little more nerdy 🤓

[@mybikeismyhappyplace]

Thanks for giving duathalon some attention. I'm primarily a cyclist thay is trying to learn to run. Hoping to do an olympic distance duathalon. I need to video my form before and after cycling. When I do bricks my hips are sore the next day.

[@grahambell9831]

Very interesting looking into this phenomenon 👏. Like all disciplines, consistent practice will unequivocally help the athlete " find their feet" during the transition to the run phase.

[@andrewstace]

How did Mark's pace drop off when his cadence was the same & stride length increased? That's really unintuitive 🤔

[@Underdog_Triathlete]

I came here to ask the same thing! Seems a bit backwards to me. Maybe that’s just the average and there was a period of outliers that really slowed the pace down?

[@quovadis5172]

Yes, it doesn’t really make sense.

[@simoneleandro_coach]

He most probably was overstriding on the second run which explains the lower run economy

[@_J.F_]

Well spotted. Something is obviously not right in the data put on the screen here.

[@Underdog_Triathlete]

@@simoneleandro_coachEven accounting for run economy, though, calculating speed should be simple if you have cadence in steps/min and stride length in meters, wouldn’t it? -At a cadence of 168 spm and a stride length of 1.58 meters, Mark’s first run would’ve been 15.92 km/h, or 3:46.6 min/km. -At the same cadence and a stride length of 1.64 meters, Mark’s second run would’ve been 16.53 km/h, or 3:37.8 min/km. Am I missing something here? Wouldn’t it be intuitive that (taking steps with equal frequency) + (going further with each step) = (moving faster)?

[@oldmandice2731]

Part of my regular weekly workouts is a 1.5 mile run to the gym followed by a 1 hour spin class (about 25 miles w/hill repeats and tabattas) then a 1.5 mile run home. I'm generally 30 secs slower per mile on the 2nd run with about the same PE.

[@vacationmode6286]

This was an interesting video. - I am mainly a runner -- We are doing a cycling class Sunday mornings and running a long run in the afternoon for a running road race coming up. its really helped run better for the long run (in the same day) which surprised me. Still trying to get a feel for my achilles and what it likes in the cycling class - do the out of the saddle sprints or not....

[@Menelaos_Nanas]

Stretching on the bike is such a nice idea ! ! ! Thanks. With all this excellent advice that you give, if we ever compete against eachother I will beat you 😂😂

[@carlbyronrodgers]

Informative.

[@Jono01]

What would have been interesting is if they compared run off the bike vs run off a run to see what effects are just from fatigue of going longer as opposed what effects are specific to running after a bike leg.

[@leslie7922]

3:14/km is a serious pace..

[@rundown132]

sprinting for most people lol

[@Unhate]

it’s reassuring to see the pros (you) dreading the run like we armatures do! 😂

[@ericjudd9223]

Any thoughts on why the stride length increases?

[@tommylobotommy]

You should show the power output vs FTP and HR on the bike to have some more insight.

[@andrewmcalister3462]

Thanks Heather and Mark for working to put some hard numbers behind the feeling of jelly legs. What were the data soles you were using?

[@heatherfell_oly]

They're called Nurrv.

[@alfredongos]

Hi #GTN Team! Please correct me if am not interpreting the tables properly but, doesn't the same cadence with a longer stride make you cover more distance, hence, go faster? On the tables I can see this for Heather and Mark, but they happened to have slower paces for the second run.

[@tommylobotommy]

That's an average, so they might have gone faster with shorter stride at the beginning and slower with much longer stride towards the end (e.g. two thirds of the distance). Would be good to see median or graphs for more clarity.

[@Stoweperry]

@tommylobotommy if that's the average then it shouldn't matter if there are outliers since they are part of the average.

[@tommylobotommy]

@@Stoweperry average is misleading, median is the better indicator. If you run 1/3 of the course with very high cadence and normal stride, and then 2/3 with lower cadence and long stride. You will have higher cadence and higher stride, but the overall pace will be slower. Just do the math in excel and see for yourself.

[@IainThacker]

As two pro's it's not quite so surprising... I'd expect much more variation for an armature!

[@jonathanzappala]

I think this gets trained with experience, by that I mean years of duathlon racing. In the early years run 2 speed improved as the run 2 went on, and now its best out of transition, like how Heather's cadence is higher at the beginning of run 2. I'm glad to hear I'm doing very well. This year I've had a 8 per km drop in a sprint, a 9 sec drop in a sprint with both runs as 5k, and a 7 sec improvement in the first and only standard du I have done. Well, I am running 5:30-6min miles, so not Mario Mola pace, but still front of the age group pack. It took years to get here, I was double that in my first duathlon in 2015. Maybe not shown in the running efficiency drop is that my run splits went from two minutes off the 5k I was running at the time, to now my first run is less than 20 seconds off my 5k PR pace. Lots of local races do the standard du 5k-40k-10k, because that fits with what the Olympic tri is doing, and the sprint du is doing in run 1. I've stayed away from that knowing it will get you a slower time.

[@gtn]

Sounds like you are smashing it! Keep up the good work and watch those numbers get better and better 🙌What tips would you give someone that is struggling with motivation?

[@larrylem3582]

For pace, how does M:S mean minutes per kilometer? Assuming it does, if cadence is the same and stride length increases, speed should be faster. Also, the stride length times the cadence does not equate to the noted km/min pace. Maybe don't believe the data.

[@joyridaz]

So what scientifically are jelly legs? And any tips to minimize them? Maybe higher cadence spinning at the end of the cycle leg?

[@bobbydiner0]

Your numbers can’t be right. Both of you ran at a slower pace in your 2nd run, but both of you had a longer stride in the 2nd run, with the exact same cadence as in you 1st runs. A longer stride with the same cadence means you are running faster… most likely your cadence numbers are wrong.

[@Saitir942]

Yeah, this has me bamboozled.

[@steven7169]

So cadence stayed the same, stride length got longer but the pace got slower. Am I missing something here or does that not add up?

[@blubbblubb6239]

I am currently training for my first sprint-tri... however, I've never felt jelly legs so far... what am I doing wrong? 😂 am I not cycling hard enough? Or not running hard enough?

[@blrun129]

for me it was always weird that my run of a TT Bike was much easier than the run of a Road bike and I'm not a good TT bike rider

[@benitocayupil6430]

I love Heather ❤❤

[@ryanochse73]

1st