Is it possible to gain any discernible level of fitness through cycling?

I ran during university with mediocre results. Afterwards, I focused on cycling for a few years. I recently returned to running and with no running specific workouts, I’m somehow better than I was before. I’m still trying to make sense of it. Maybe it was the 20h+ weeks.

Given that elite cyclists are some of the fittest people on Earth, with some of the highest recorded Vo2 Max scores (Greg LeMond had a Vo2 Max of 93), then yeah, I'd say cycling gets you fit.

In order to transfer that cycling fitness to running, a cyclist needs to improve his/her running economy.

Your cyclist friend, if he isn't overweight (running punishes heaviness more than cycling, unless you're going uphill), should make huge gains in this area relatively quickly if he runs more regularly.

40 year runner and now a 3 year cyclist on the side. Just my observation, but for the "average" person, I'd say that running translates better to beginning cycling more than the other way around. Part of it may be that the average runner seems to be lighter than the average cyclist. I became a decent cyclist quicker than I think I would have become a decent runner after 40 years of riding. Cardiovascular strength might be similar but no substitute for the difference in pounding on the legs.

I have been pretty decent at both, running and cycling. Our heart and lungs do not know if you are running, riding, swimming etc. The amount of aerobic hours of training available with rising and swimming out does the time spent running. A 2:05 marathoner is getting plenty of training in with 140mi weeks. the average person can’t physically withstand those miles. Give the average reader here months of 50mi weeks with 15hrs on a bikes/week and they would run faster than they are right now.

Cyclists, even fit cyclists, have a hard time running. It's not the same at all. Cyclists don't have to support their own weight, the bike does that. Runners have to support 3-4 times their body weight one leg at a time. A lot of pounding on the body running. None cycling. Cyclists also go much faster than runners so they can benefit from cooling breeze. Runners don't go fast enough to benefit. Cyclists can coast going downhill and around curves and still maintain speed. Runners have to always put out energy to keep momentum going. Going the speed they do, cyclists can also get pulled along by the peloton and save energy. Runners get only mental benefit from running in a group, no physical benefit.

Drafting behind other runners reduces drag force, so there is a physical benefit, even if it isn't as large as it is in cycling. Here's a good article on the topic:

outsideonline.com

Quantifying the Benefits of Drafting for Runners

mmirhashem

A new aerodynamic analysis runs the numbers on exactly where to run when you’re behind someone else

Link:www.outsideonline.com/health/training-...

Also, as soon as you get onto a long climb in cycling, all of the differences you mention above (minus the impact) cease to be.

I'm guessing you've never seriously experimented with cycling as a cross training tool? I can tell you from experience that there are huge gains to be had.

I personally went from running 70 miles/wk with no cycling, to now only running roughly 45 miles/wk, but with 5-6 hours of cycling (with 1 hour at a high intensity) per week. My 5k time has improved by 54 seconds since doing so, and my half marathon by 5 1/2 minutes.

I'm a hobby cyclist (but better than most; for reference, peak fitness in Sept was an FTP of 5.0 watts/kg (375W, 75kg), up from a more typical summer value around 4.8.

I had surgery in September and gained weight while losing fitness for the next three months. In December I tried a beep test - it was the first running I'd done since April, and I got to 13. Cycling definitely builds fitness. (I was never a particularly good runner.)

Sounds like this guy uses zwift which is online riding and racing. A couple hundred miles a week on that will get you in great shape if you do workouts and races.

Most serious cyclists can drop in and jog a 5k. I would guess there's a huge variation in their ability based on their running background and how much they do other forms of activity. A cyclist that goes hiking once a week or does some casual sports is going to have a big advantage over the ones that don't. As far as getting fit, based on what we see on the women's college scene as well as triathlons, a ton of cross training with 2-3 key running workouts is enough to bring out most of your potential

Don't believe those VO2max scores, they are ridiculous made up numbers.

Do you cycle?

Cyclists face a huge problem converting biking fitness to running fitness because on a bike, your feet and ankles are just moving up down. When we run our feet and ankles are rolling and twisting in all directions.
Adapting to the change of technique and sustaining it requires starting from scratch basically. In other words, thousands of miles of running is required to be competitive.

Nice humblebrag. FTP of 5w/kg should have you winning Cat 1 races.

That DurianRider chapter was funny as hell. I really miss his on board cycling videos. I think you either love his style or hate him.

Phil Gaimon is 100% on the juice, and it isn't just fruit or cow juice. It's amusing how people defend him against doping accusations, like they're getting any benefits from his brand sponsorships. Even recreational riders dope to gain an edge in their cat4 weekly sunday criterium down at the local industrial park- just the nature of the sport.

Props to DurianRider for both being open about ped use and making money from it. Man's living the dream.

According to LRC, the average couch potato can run a mid-17 5k off of no training, so your friend should have no problem.

Ride 4 days a week for 1.5 - 2 hours at an honest pace that gets your HR to 70% MHR

Do 2 quality run sessions on the track

Traditional weekend long run

Most runners would do well on such a plan for any distance except marathon/half-marathon. For those distances, add some easy running to your bike days (5-6 miles) so that you are better accustomed to the pounding of longer races.

Yep. Owns 3 road bikes but only rides 25 miles a week. Pretends to not know about Zwift. Rojo bots still fall for it.

Yeah, I thought the same thing! I wish I could pull 5w/kg.

FWIW, I rely on cycling as a key part of my aerobic base. I ran 2:33, 32:3X, and 15:5X at age 40+ off of about 45 mi/wk running and 40 mi/wk cycling. Early part of the year was much more tilted toward cycling (like 15-20 mi/wk running and 80-120 mi/wk cycling). Ended up with a bit over 1000 mi running on the year and a bit over 3000 mi cycling. I've had a similar mix over the past 5 years or so, and I think it has been key to helping me minimize injury -- I've not been historically durable.

This story is kind of embarrassing but whatever. When I was an out of shape 25-year-old, I decided to run a 5k for the hell of it in April and got a ridiculously slow time of 28:xx. Most painful experience of my life, and could barely walk for a week afterwards.

A month later, I bought a cheap heavy road bike and starting bike commuting to and from work (8 hilly miles each way) and did one long 3-4 hour ride on most Saturdays. Not super intense, mostly me and a friend would ride an hour, stop for a beer, ride another hour, stop for lunch, then go back home, that type of thing.

Ran another 5k time trial that October and hit 23:17 I only lost like 7lbs in that time frame so the 5 minute reduction in 5k time was purely from cycling. So for someone that's out of shape, cycling can ABSOLUTELY get you great fitness with almost no injury risk. If you're looking to go <17min 5k, not sure cycling is going to get you there.