He can start by going to the gym NOW to strengthen his leg and abdominal muscles. His recovery time may decrease and a regular regimen (prescribed by an orthopedist) can really speed up healing. In general, recovery time will depend upon the individual. Full recovery from a hip surgery can take anywhere from 3-6 months, or even a year in some cases.

Sex is safest 6-8 weeks after surgery. You should both avoid vigorous sex and more extreme positions. If he experiences any pain, you should stop. Finally, his surgeon can advise give the final OK for sex. Don't hesitate to ask. Doctors are human, too!