[quote author="Jeremy Richmond" date="1260216355"][I would contend that jump squats as a method of improving speed when running is wishful thinking. GCT’s in a jump squat would be far more than 300ms compared to 100ms needed for sprinting at speed. Normal plyometrics provides more than enough stimulus (too much load in fact) with better GCT’s than jump squatting.
Jump squats (30% of 1RM for maximal power) have only been shown to improve 5m times with no added improvement after that. [b]Jump squats with more weight (80% of 1RM) slows you down.[/b] (McBride et al. 2002, Wilson et al. 1992, Lyttle et al. 1996).
Sets of 6 reps seems to work better than sets of 8 reps.
You’re probably right that jump squats have a greater impact on starts and accel, I think because they are quad dominant, not necessarily because of slower GCT.[/quote]
I really like jump squats but there are enough studies that highlight its limitations.
Method Author Distance Pre Post Difference % change
Jump squats 30% 1RM Wilson 1992 30m 4.54 4.49 0.05 1.10%
Weights 75% 1RM Wilson 1992 4.43 4.48 -0.05 -1.13%
Plyometric depth jumps 0.2-0.8m Wilson 1992 4.61 4.63 -0.02 -0.43%
Control Wilson 1992 4.73 4.71 0.02 0.42%
Combined squat / drop jump Lyttle 1996 40m 5.48 5.44 0.04 0.73%
Maximum power jump squat Lyttle 1996 5.49 5.56 -0.07 -1.27%
Control Lyttle 1996 5.59 5.56 0.03 0.54%