Velo Core Exercises For Stability and Injury Prevention on the Bike.
That makes your body fit, to keep fit your brains you may need for some time.

 #1: Boxer Crunches: Both ways 20 repetitions.

#2: Leg Raise: 20 reps and hold for 2 seconds.

#3: Alternate Leg and Arm Raise: 20 reps and pause 2 seconds.

#4: Plank Pose Hold for 60 seconds and work up to 3 minutes.

#5: Alternate Plank Pose: Switch from Left to Right hold for 2 seconds each side for 20 reps.

#6: Side Plank Pose hinge up (pause seconds) and down for 20 reps.

#7: Option 2 Side Plank Pose: Hold for 60 seconds each side, with arms extended.

#8: Pike Crunch: Work up to 20 Reps.