Add strength…
Day 4. Do regular basic leg and core exercises. Make sure you plan phases of progression
ACTION REQUIRED: - SET YOURSELF A TARGET >>
ACTION REQUIRED: - SET YOURSELF A TARGET >>

Daily bodyweight exercises make a huge impact to muscular endurance
Do not underestimate the impact these will have.
Example: 30 Sit-ups and 30 squats per day. Add 10 more each week.
If this is too easy or hard adapt the volume to suit you.
Try not to over do it and effect your cycling efforts. Its a balancing act.