One club, 30 reps can match the full overspeed protocol
In a follow-up study on weighted-club speed training, the instructor found statistically no difference in results between the full protocol - all three clubs with lots of reps - and doing just 30 reps with a single club. The takeaway is that you may not need the full multi-club, high-rep protocol to get the same benefit.
Channel: Mark Immelman
Watch official source at 34:26Why this context matters
From their overspeed / weighted-club speed-training studies.