I am 50 years old and just coming off my first significant injury in over 2 years which sidelined me for 4 weeks. I was consisrtly doing 25-40 miles / week up till the injury ( bad PF) . I did a few short 1-3 mile jogs and 30-45 min sessions on the spin bike 2-3 x a week during the lay- off. Things are getting better but I need some guidance on how to come back and how quickly. I was running 5-6 x / week prior to the injury. Any help is appreciated.