If I can ride 15-20 miles on a mountain bike at around 14mph on a decent trail how far can I jog on the same trail?
Or what is the ratio of bike/jog for a person with a given fitness level and endurance?
Not very far at all if all you’ve been doing is riding a bike. You need to build up your “running legs”.
That said, in my running days I could go appx. 2.5 miles on a bike(road bike w/high pressure tires) in the same time/heart rate as running one mile.
However, you can bike for a much longer time at the same aerobic effort level as you don’t have the impact forces fatiguing your legs.
So biking and running use different sets of muscles? What about swimming? I find that running is harder on my knees than biking or swimming.
Partly it’s dealing with the high impact of running.
Runners use the rear of the leg-hamstrings and calves. Quads come into play when running hills, up and down.
Cycling uses mainly the quads and gluteals with an assist from the hamstrings.
Swimming is whole body with the primary focus on upper.
There’s no correlation. In my own experience: I can ride a bike for hours, but get debilitating lower back spasms from running, or even fast walking. If I continue, my calf muscles start complaining.
In my experience, jogging and biking use two different sets of muscles. I once did a 20 mile bike ride (in hilly Scottish terrain) when I was running regularly 5-11 miles per day. I was a complete wreck at the end of that trip. Now, granted, it was quite a hilly trail, but my legs were shaking and felt like rubber when I got to my destination in Oban. Frankly, I don’t even remember how I got back, as the first thing I did was find a pub to help numb the pain.
Cardiovascularly, I would suspect you have the fitness to run something like 5-6 miles, but if you’re not used to running, you’ll probably tire out quickly.
I’m not sure exactly the answer, but I’ve often mused on the efficiency of bike riding, to wit, I, a 50+ year old sedentary sort of guy could probably get up off the couch, get on his bike and, with maybe a week or two of training, ride 26 miles in the same time as a world class marathoner would take to run it after years of training.
Actually, the embarrassing thing is how close the race would probably be – if I were in decent shape, it wouldn’t even be close.
You said jog and not speedy run so I’m coming from that angle here. Running is a weight bearing exercise that does use some different muscles. A regular biker can be in better cardiovascular condition than a recreational jogger. There is quite a bit of transference between biking and running. This is why hockey players work out on a bike to build leg turnover and help their speed skating. Skating is similar to running.
My bottom line is that you are in good shape and can ride hard for 60" or so, you should easily be able to jog for half an hour or more so probably about four miles. After a few days of getting your running legs, you should be able to do that 60" jogging. I base this on my coming off of injuries where I biked until the injury healed and switched to 100% running.
There’s not an exact correlation like that between the different aerobic exercises; it varies between people. I can jog about 10 miles but I can barely swim 20m without being exhausted.
Depends on the person. When I’m swimming, I find I get far more power out of my legs than out of my arms. While I was learning, the only reason I ever used my arms at all was that my instructor insisted that I wasn’t swimming if I didn’t (I don’t remember what it was that he called what I was doing… Torpedoing, maybe?).
What if you’re running barefoot while wearing a thong?
I’ve tried barefooting, never again.
As far as you want to…WAhaha!
There is really no actual limit though, as long as you take breaks and keep hydrated, a person can ride/jog as far as he/she wants too, it’s the pace that gets ya’, and the heat. There’s one man that can jog for hours on end without stopping and he slowly goes faster as the day wears on, until he reaches max speed of course. All he needs is water now and again.
Well we can look at it through the lens of the triathlete. Well conditioned for both running and cycling the ironman has a 100 mile cycle portion and a 26.2 mile run. The bike takes longer but is less wear and tear. So figure roughly 4:1 bike:run.
Looking through my personal lens as someone who has done some triathlon training - getting over 12 miles in a weekly long run takes me about the same portion of my conditioning programming as doing a 50 mile bike ride does. Also a very similar ratio, roughly 4:1.
Of course if one has not been training for both the rule will not apply. The muscles groups are being used differently. That said I think the biking transfers over to distance running more easily than the converse. (That is just IMHO however.)
And as to the concept of swimming being upper body, not according to some respected for their swim training.
Their perspective is that the core provides the power, not the arms, or the legs. (I can’t say that I’ve done too well at ever implementing that … I’ve been swum over many many times and know that I have a very inefficient stroke.)
I got my 2.5:1 from riding and running at similar heart rates/effort.
Also, a little interesting data:
US 40K cycling record-47:35 times 2.5=1:59(projected)
World record marathon 40K split=1:57:34
Cycling 1 hour record 51.5K/31.98 miles/ 2.5=12.796 miles
Running 1 hour=13.217 miles
The question is if time and heart rate is, in this case, the same as effort. Cycling does not have the either the pounding or the “eccentric muscle use” (think negative reps in lifting) that running has. An elite ironman triathlete can spend 4 1/2 miles cycling 100 miles. If they spent 4 1/2 miles running at their same level of effort ran the run portion they’d have to be running nearly 50 miles.
I believe it is. If your activity requires a certain amount of oxygen, your heart has to beat at a certain rate to supply the O2.
The limiting factor is not aerobic fatigue but muscular and energy supplies at longer distances.
The 50 mile record is 4:51 while the best bike leg in an Ironman is 4:18.
Your skill, efficiency, and natural talent for an activity is a huge factor. I come from a cycling background and took up triathlon a few years ago. Even though I could bike 65-100 miles at a decent pace I barely managed a slow 3 miles running at first. It took me a long time to build up my speed/ distance and I am still much better on the bike. Even at a relatively slow running pace my heart rate is through the roof.
The triathlons I do rank your time for each individual sport and even after 2 years of running I always rank significantly higher on the bike portion. The race I just completed I ranked 61st overall on the bike and 91st on the run (and 126th on the swim 
).
Not sure what your point is here.
In any case let’s take your approach but get to the bottom line - the calories burned per mile. Running stays the same per mile pretty much, about 110 Cal/mile for a 155 pound individual; cycling changes with speed.
So if we presume our op is about 155 pounds then the listed example is close to his specific question. Riding 20 miles at 15 mph is the same calories burned as a 5.63 mile run on the same trail. Not far from the conversion factor of 4 I was coming up with. At faster bike speeds however your 2.5 conversion factor is more accurate. So this time we are both right! 