Check two things before doing overspeed training
The instructor gives two checks before doing overspeed (speed) training: pass the mobility tests, and make sure your strength and power numbers are not more than 15 percentage points apart from your current clubhead-speed numbers. He says single-digit players often swing far faster than they can physically support. If you fail the mobility tests or the gap is bigger than 15 points, he says you should fix those areas first, after which overspeed training can be a useful tool.
Channel: Mark Immelman
Watch official source at 35:45