There is a couple of studies on strength training and improved economy in running and cycling.
In these studies they used 4 exercises and a progressive load from 3×10 reps to 3×4 reps after 16 weeks.
The first 4 weeks you can do one session per week. After 4 weeks you can do 2 sessions if you have the time.
You can find the plan below. P1 is first session P2 second. RM is your repetition maximum. You can guesstimate it or try to see what you max is. Be careful.
| Week 1-4 Squat (Half) P1 3x10RM Leg press, Single leg P1 3x10RM Hip flexion single leg P1 3x10RM Calf raises P1 3x10RM | Week 5-8 Squat (half) P1 3x10RM, P2 3x6rm Leg press, Single leg P1 3x10RM, P2 3x6rm Hip flexion single leg P1 3x10RM, P2 3x6rm Calf raises P1 3x10RM, P2 3x6rm |
| Week 9-12 Squat (Half) P1 3x8RM, P2 3x5RM Leg press, Single leg P1 3x8RM, P2 3x5RM Hip flexion single leg P1 3x8RM, P2 3x5RM Calf raises P1 3x8RM, P2 3x5RM | Week 13-16 Squat (Half) P1 3x6RM,P2 3x4RM Leg press, Single leg P1 3x6RM,P2 3x4RM Hip flexion single leg P1 3x6RM,P2 3x4R Calf raises P1 3x6RM,P2 3x4RM |
After week 16 you can keep doing week 16 on repeat just remember to increase the weights.
During race season or when you have less time try to complete one maintenance session because that will help you keep your strength gains.
maintenance session:
Squat (Half) 2 x 5 reps @80–85% of 1RM
Leg press, Single leg 2 x 5 reps @80–85% of 1RM
Hip flexion single leg 1 x 6RM
Calf raises 1 x 6RM