I feel that the most important benefit of strength training for cyclists is injury prevention. I do a circuit style workout involving mostly compound movements twice a week (one day upper body, one day lower). Upper body day I do pushing and pulling exercises (bench press/pushups, pull ups, military press, rows). Lower body day I do squats and dead lifts (nothing super heavy) and some leg curls and leg extensions to address the muscle imbalances that cycling promotes. 3 sets of each exercise, 10-15 reps
As far as core work, I've found that doing planks and side planks at least 3 times a week has helped with my back pain issues and also helped my endurance
I agree 100%. My philosophy is like this:
Strength - For manhandling the bike through corners and over trail features. For quick bursts of energy, sprints and short steep climbs.
A comprehensive weights routine utilising compound movements with free weights aimed at strength and conditioning done 3-4 times a week and split into upper body, lower body and core days.
Mobility - For staying loose and fluid in handling the bike through corners, over trail feathers and down steep descents.
A full stretching routine done after, not before excercise and on rest days.
Endurance - Both aerobic and anaerobic, for staying fresh throughout the ride and keeping your performance from slipping, both mentally and physically.
The ride itself can cover the aerobic side but I also like to do one or two 5k slow pace runs a week. High rep medium weight on lifting days as well as some sprinting helps with the anaerobic side.
Injury Prevention - Healthy joints and ligaments, functional amount of muscle mass to support joints and bones during a crash.
Stretching, body weight excercises and the weight lifting take care of this.
Recovery and Growth - For repairing and improving the body for the next ride so that you are always progressing.
Healthy whole food diet full of veg, fruit, nuts, low GI carbs, mono and poly fats and LOT's of lean protein. Healthy 6-8 hrs of sleep and days off will take care of this.
This all might seem like a lot of effort just to ride a bike but I see this as a philosophy for getting the most out of life, not just MTB riding. The bike riding is just one part of an over all idea to stay fit, healthy, mobile and strong for everyday life now at 32yrs old and for the future as head towards later years because you better believe I plan on hitting the trails for however many more years are left to me. When it comes to getting older, you either use it or loose it.
And this is all coming from a guy who 4yrs ago was a 266lb at 5'11" couch potato, who believed fit people where just born lucky. 90lbs of fat loss later and I can tell you it's about taking responsibility for your own choices waking up to your own potential and it's never to late to do so.