I picked up swing speed by going to a heavier stiffer shaft. It allowed me to swing at my normal speed because my brain new i wasn't going to over power it.
Prior to this i had a lighter/weaker shaft that i could overpower and balloon. Thus i swung slower because if i turned it up the ball wouldn't go anywhere.
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I'm not a TGM or PGA certified Pro, but I did stay at a Holiday Inn Express last night