I was making some pretty good progress with MAF after taking about 4 months off from running. I brought my pace from 10:00 down to about 8:00, but now I think I might have a stress fracture in my right tibia. I am going to take time off until I can get a bone scan, just so I'll have a jump on the recovery period if it turns out to be a stress fracture.
I had planned on doing a 50k on June 1st, so I'd like to cross train to stay in solid shape. I have a gym membership, so I guess I can come to terms with hitting the bike or elliptical for 4-6 weeks if need be. My question is what heart rate I should cross train at. Should I cross train at MAF, would going at a higher heart rate or intervals ruin the MAF base I had going? Thanks for any help.
Sorry to hear about your injury. Nice work getting your aerobic speed down to 8:00.
If you shift to another form of training, approach it the same way as you would running. Do an MAF test, then monitor your aerobic speed at MAF. If you think you're ready for harder stuff, go for it, but monitor your speed at MAF. It should improve when you add anything over MAF, not get worse or hit a prolonged plateau. I'm not sure which Cross-training is best to maintain running, though I remember reading in the distant past something about the stationary bike being a good replacement. There's that new alter-G contraption, water-running, and the two you've mentioned. I'm sure there are plenty of people around RA that can answer this. Google!
If you can still handle some long walks, they will also help. You can get those slow-twitchers pretty exhausted with a long one.
Good luck. Heal!