I am a mountainbiker (XC), and I am just about to finish my racing season. After the usual 2-3 weeks of alternative training after the season, I am thinking about training weights 1-2 times a week in addition to on-the-bike strenght training, endurance rides and anaerobic threshold intervals. Give me your opinions on why/why not weight training is a good supplementary, and how many reps/sets/workload you would train during the off-season.
The general belief is to use high-reps for endurance sports, but I disagree with this. The objective is to increase max. power, to be able to apply it on the bike you of course still need to ride on the bike as well.
Max. power can be increased quite easily e.g. using HIT (High Intensity Training) meaning only one set at maximum intensity. This does require a good warm-up but is very effective.
What I do:
only 2 exercises, only once a week (takes at least 3 days to recover) (middle of the week since I then have no opportunity to ride):
1. hamstrings: bar-bell straight leg deadlift (lifting bar-bell from the ground with straight legs, has to be performed very carefully, but is very effective)
2. quadriceps: bar-bell squat (bending knee with bar-bell).
perform a general warm-up, including good stretching for the involving muscles.
do a warm-up set with half the weight you would use for the normal set (so the warm-up weight also increases along the line). Double the weight and then perform a set of up to 12 reps to exhaustion.
In my case the weight I use for both exercises is almost the same, e.g.:
1x12 warm-up 50kg
1x8 (up to 12) 100kg
Only arriving at 12 reps, I increase the weight with 5%. This ensures your body gets the time to adapt to the weight and includes a trapezium effect
weight week1: 8 reps, week2: 10 reps, week3: 12 reps.
weight+5% week4: 8 reps, etc.
After a while you may reach a plateau and may have to go for more sets, but this is very effective when starting out.
In total this only takes about 15min. and only requires a bar-bell set (which you can also use for other exercises like bar-bell bench press).
Of course, don't take this for granted, it's what works for me.