I recently (well 1.5 months ago) came down with a hip injury...mainly caused my hip misalignment. I am working on getting that fixed...I have been trying to get back into running but it will not get better so I decided to strctly xtrain until it is gone. Currently I have been using the elliptical for my xtraining. I use a hr monitor and calculated that with a resting hr of 43 and being 23 yrs/f. old I have a max of 197. My half time is 1:28 and I usually train at under 7 min pace 45 miles a week. Lately I have been able to get my hr up to 166 on a hard day and keep it between 150-160 on a comfortably hard day. Does anyone know much about hr training. I am just trying to keep myself in good cardiovascular shape until I can run again. PLEASE HELP IF YOU CAN!