core strength exercises are always helpful -

http://www.youtube.com/watch?v=KmHqBYFYwmc

http://www.youtube.com/watch?v=a_Kfc0mp2Mw&list=PLUMQ5KNNAMhQ9qcEN2UvINuPTPnq620ij

http://www.youtube.com/watch?v=aVct9di8wlE

I've started doing the following once a week (or as time allows);

Sit Ups
Press Ups
Various Dumb Bell reps for upper body
Squats
Lunges
Planks

For me, this is to maintain what muscle I have, and strengthen my core.

I've only been doing this since the beginning of the new year so | can't really say if it's working or not, though I'd like to think it is! :happy:

Swimming!
I signed up for a 10 week session of improver lessons in October last year and it lifted my fitness on the bike up so much I have moved up from group B to Group A in my club

bump

Another vote for lunges and core work. Obviously, anything that works the quads, glutes, and core for obvious reasons.

The lunges and squats made very noticeable improvement to my hill climbing routines.

I would add stretching/flexiblity to the list as well. Flexibility = Aero = Less Drag = Distance.

November and December I was hardcoring it in the gym, doing 5x5 twice a week and 5x15 twice a week mostly on legs (squat, leg extensions, leg curls, calf raises). Thats right 4 leg sessions a week which killed my legs for sure and I didn't really do any riding but I put 29mm on my thigh measurement in 6-7 weeks. Been doing lots of high cadence work since getting back to riding and now I'm climbing like a mountain goat. The 5x15 part really helped my endurance which is handy being as I'm racing mtb endurance, mtb ultras, mtb unsupported ITT's etc.

I'm still doing some leg weights, dead lifting and incline press but 3x10 once a week and eating at a deficit so this is just maintenance really. Most of my off the bike work at the moment is core. Exercises such as: Glute bridge, plank, scissor kicks, Russian twist, weighted hyper-extensions all done as a circuit.

I hired a coach this off season. He put me on twice a week weights and 5 days a week stationary bike. The weights made all the difference in the world. First time I got out on the road this season I tried one of the climbs from last year and cruised up. The weights vary depending on what the coach is pushing that week, but Goblet squats, lunges, leg presses, hamstring curls and leg extensions are all staples. Flexibility and core strength are the other staples. Can't say enough about the core and flexibility exercises. The strength training and flexibility training limit the severity of injuries as well as improving performance and recovery. The problem with all bike and no weights is your bones will get more fragile because of the decreased stress to the bones. People who ride a lot really should incorporate weights or some other strength training to improve performance as well as reduce injuries.

I think the best off-bike is to rest your muscle groups. Working core is good for keeping your back in proper shape. Weight lifting helps the upper body, too.

Probably the best thing that's helped me on hills is...more hills....lots. Gnarly the better. I also added some new music in my playlist to keep it spicey.