Walking/Hiking

[jammin87]

If you're on the South Downs, have you thought of making it a weekend session with a mate and camp out? Obviously more weight but they're good weekends.
For a single day, probably work out a route in a big loop that'll take you more than three to four hours rather than one big hill over and over.
If you're doing this as a way to get back into the phys then find a pace that's not going to hurt you anymore. Obviously that's up to you to work out.