Bike/Run-training. Crossover benefits or counter productive?

Triathlon Forum
1

Hi!

I’ve never been the runner-type, in the sense that my run training has been very unconsistent, and I never had any real volume or structure. I would typically run 1-3 times pr week, running approx 10 - 30-40k pr week (probably avg of around 20-25k/week). Instead, I’ve spent 85% of my time on the bike. I’ve always been curious to the crossover benefits from cycling to running, and vica versa. I’ve read quite a bit of posts around here on this subject, and the consensus seems to be that there is little cross-over benefits etc. This has been contrary to my own feeling, as I felt I had a pretty decent endurance-base from the bike, that would transfer over to my run. My problem has always been that the legs shut down from the constant pounding of the run. Still, I have been pretty happy with my tri-running even with the kinda limited run volume. Best run splits last season were: Sprint - 19:30, Oly - 42:00, HM, 1:36:00, IM 3:57.

This winter I did a real run focus for the first time ever. I’ve been running pretty consistently 5-6 times pr week, and have averaged about 55k/week for 6 months now. During that phase, I had some interesting experiences on the crossover-effects of running/biking that I thought I’d share, and hopefully get other ppls take on.

I came into my running block with pretty decent (for me!) fitness, with the bike being my strong suit. Basically, from mid september last year I cut my bike training down to one session pr week. I would do 2x20 somewhere in the region of 93 - 97 % of FTP once every week. Also, I should add that I commute about 16k to/from work 5 days a week, on the bike (downhill to work - 15min easy, uphill home - 30min easy uphill). Other than this, all my training has been running.

I kept doing the weekly 2x20 untill end of December. During that period, my bike-fitness seemed to stay pretty much put, while I had a nice increase in running fitness. There is a 10k series where I live, and I’ve been using thise every 3 weeks to get a good, hard workout and test out where I am fitness wise. I started the run-focus with a 10k PB of around 40:20, and got it down to around 39:10 the first 3 months of my run-block.

After December I quit doing the weekly 2x20 on the bike (but continued commuting to work). For the next two months my run-fitness pretty much stayed put. I ran 50-60-70k every week, but my 10k level seemed to stay the same. No PR’s on the 10k during this block.

Come march I started the 2x20’s again once a week (time to boost bike-fitness for a june IM!). The funny thing was that when re-introducing 2x20’s I found that:

  • My bike-fitness was pretty much the same as when i left of (was able to hold same watts in the 2x20 as before the “bike-break”).
  • I set a new pretty big 10k PR on first attempt after reintroducing 2x20’s! got 10k down from 39:10 to 38:25!)

Either there are some other factors in play / conicidences, or I am experiencing that my run training has a positiv effect on my biking, and vica versa! Does anyone else have similar experiences?

2

That a very interesting case-study, thanks for posting it!

My immediate thought would be that your run-specific training block (where you cut out the 2x 20s) would likely have coincided with the deepest darkest depths of winter. Do you feel as though the weather could have affected your running and that your static times could be due to adverse running conditions rather than a failure to improve run fitness over this time?

3

I’ve found that my run training helps my biking more than biking helps my run training.

I come from cycling FWIW

jaretj

4

You could be right in that the months “off” 2x20 were dark and cold. The running conditions were not that bad, but the low temps (and the fact that I would be abit more loaded with clothes) could naturally be a factor. However - it was not just the mere running-times. I also felt abit heavier and slower in those months, no “spark” when running.

5

Yes there is a benefit. Went from being a cyclist training 1-4 hours a day to runner training 1-2 hours a day. Right away, my 10Ks were in the 40s and down to 36 minutes within 6 months. My first marathon was 2:48 after a few years of building mileage. Lydiard said that cycling had a great deal to do with those results. YMMV

If one is a heavier person, it would probably be good to lose weight on the bike and build up aerobically rather than doing it with running. Since that is probably not the case with you, enjoy the cycling.

Jack Foster was an avid cyclist first and then a great runner http://www.mastersathletics.net/index.php?id=1742

6

Impressive progression. I probably havent been cycling as much as you, but I’ve been pretty consistent on the bike from about 2008 (a good 7-8 years cycling base). I gradually started running, but since I kept the volume really low the first years I didnt have the results you reference below. In addition - I went straight for the marathon in my first year introducing running:)

I will be running this same marathon this year for the third time in a row, and I am kinda excited to see what results I’ll get this year with a better base. Just to make another case study, here is milage and marathon finishing times for 2014 and 2015 for myself:

  • 2014: Ran a total of 507 km in the period 1.10.2013 to 20.4.2014 (29 weeks = 17k/week avg): Marathon run on 26.4.2014 = 3:26.
  • 2015: Ran a total of 597 km in the period of 1.10.2014 to 20.4.2015 (29 weeks = 20.5k/week avg): Marathon run on 25.4.2015 = 3:21
  • 2016: Ran a total of 1 285 km in the period of 1.20.2015 until today (24 weeks = 53.5k/week avg): Maraton on on 30.4.2016 = ???

I’m kinda in the blue as to what time I should aim for this year, but thinking that somewhere between 3 and 3:10 should be possible. Sub 3 - maybe next year…