You having both eyes done or one? I had both eyes done for PRK, one with astigmatism, one without. The astigmatism eye took longer to recover, and it's still not where I want it (there's more zapping to counteract the astigmatism)
Either way, you won't be exercising hard for at least a week, probably 2. It takes around 7-14 days for the epithelial layer to regenerate (for me, it was on the longer end, and I seem to heal faster under paleo as well). Eyes are slower to heal because of reduced bloodflow to the eye. You definitely do not want ANY sweat in your eyes while it heals. :)
LASIK's faster in that respect than PRK, but the whole flap and weakness for life thing gives me the heebie jeebies.
I didn't do IF, so can't comment on that.
Adding on to what Marie said. The doctor probably already told you, but you'll probably have 3 prescriptions. Antibiotic, steroid, and painkiller (codeine). You should already have them now (the sterioid was never in stock at my pharmacy, so they had to order in).
Antibiotic = critical. They take off the outer layer of skin on your cornea. This is a line of defense protecting your eyes from infection. Even with a good immune system, Vit D, etc. Don't forget to take the antibiotic! Take no chances whatsoever on this. Use a clock/timer/reminder for the drops.
Steroid = critical. This is what helps regenerate the outer layer of skin faster. Something logical they don't always mention. This also can help other living things grow faster as well. Thus the antibiotic is even more important in that first few days.
Codeine = depends on your pain threshold. I didn't need it at all. Everyone else that's done it around me were gulping it down like mad. Like any pain pill, it works best when the pain is starting vs. when it is fully in swing.
Eye drops (systane/refresh). Use them frequently. Get the small vials vs the big bottles. The vials have no preservative, the bottles do. You want to avoid that while the epithelial layer is healing. Dry eyes=eyes that aren't healing as fast + pain.
Omega-3's are supposed to help with dry eye as well. I stepped up the fish oil a bit.
It's a bit odd that you're having the surgery on Friday. Are you having the post op check on Saturday or Monday? Mine wouldn't do the surgery without a scheduled check the next day (and didn't do LASIK/PRK on Fridays). Might be just him, but some of the negative stuff hits so fast with all the drugs, that he wanted to ensure nothing bad started off.
Finally, check out your eyes before and after the surgery. Maybe take some pictures. Your vision will be at least decent right after the surgery, will deteriorate a lot over the next week, then get better over the next 3 months+. But what you'll want to do monitor things. ANY funkiness or unexpectedness with the eyes (sudden white spots, unexpected pain) get an appointment to get checked out immediately.