How to improve cycling efficiency with strength training?

Where would you invest time in strength training if you have 8 weeks with 2 training sessions per week?

1- Exercises of horizontal leg press with a single leg that allow thrusts for 3 minutes (80 RPM-40Ecc + 40conc); 3 series with 30 '' recovery between one leg and the other and 1 minute of recovery between the sets.

2- Horizontal leg press exercises with a single leg that allow 6RM thrusts for 6 sets with recovery of 2 'per set and 30' 'between one leg and the other.

I would like to receive your opinion.