This is an excerpt from a 1971 Fred Grace article, courtesy of Liam Tweed.
At about age 40 I started upping my reps. At 69, in a single workout, I did 3,000 squats in sets of 100. I used 50% of bodyweight on the bar. Ironman readers know about my high rep routines . . .
With 50% of bodyweight on the bar, do the following reps:
50 Clean & Jerks
50 Dead Hang Snatches
150 Bench Presses
2,000 Squats in 100 rep sets
When feeling frisky do a set of 500.
With bodyweight on the bar do 300 deadlifts.
Try 1,000 parallel bar dips in one workout.
With a fifth of bodyweight on a dumbbell swing it overhead 500 times.
But to really send the heart into orbit, try jumping squats. I call them jumpies. You know what weight to use. Jump as high as you can and come down to a full squat; rebound to another jump, legs tucked under. Try 50 reps.