Let's say I bike bout 5 hours a week the other 5-7 hours i'm out on the roads.
I don't think the Heart knows the difference between my HR being 135 on a bike or on a road. I think 7 hours of running is enough to repair my legs for a marathon (per week).
Thoughts? Anyone done nearly half of their marathon training on a road bike dialing in the HR? If so what was your result?
Why? Can your body not handle 10-12 hours of running?
A guy I know tried something like this this past fall. He crashed and burned pretty badly in the second half of the race. He is not a particularly talented runner, but he was in pretty good running shape for him, running some of his better race times at shorter distances leading up to the race.
Fairly anecdotal, but on the other hand, it is also pretty consistent with what one might expect.
My take is that biking (or any other kind of cross training) is a good supplement, but, assuming that you are looking to truly race and not just complete the event, it should come after you have maxed out your running miles first.
I suspect that the physiology on this point goes beyond just an issue of heart rate.
- There is the muscle fatigue issue, which you noted already. I think you may underestimate how important the pounding your legs take from the extra hours of running is. It is not just getting used to the feel of tired legs, but it is about building muscle and connective tissue strength as a result of high impact exercise.
- There is also the fact that while both cycling and running emphasize the same muscle groups, they emphasize them in different ways. As a result of the shifted emphasis, the changes to the cells in those muscles will take place in a way that is less efficient than if you emphasized running. Basically, you will increase the number of mitochondria in your cycling emphasized muscle tissue with cycling, and you will not get a one-for-one benefit from that when you run.
Am I living in the twilight zone? The Boston Marathon weather was terrible!
Des Linden: "The entire sport" has changed since she first started running Boston.
Ryan Eiler, 3rd American man at Boston, almost out of nowhere
Matt Choi was drinking beer halfway through the Boston Marathon
2024 College Track & Field Open Coaching Positions Discussion