I have to agree, and disagree. There is a fine balance, but for my own training, I think excessive power/strength work always lowers my 30 time.
At the start of the summer i had no gym membership, so I occasionally (once a week), did some lunges with a sofa, but focused mostly on sprinting at top speed, and bounding. My vert exploded (and later I found out my strength gains remained the same or slightly increased despite only moderate laod lifting).
I think once you hit a a plateau in the 30m dash by just sprinting, the squatting will help, the problem is that RFD is so much different in a sprint than in a squat, even a jump squat, that it may slow you down if you are not sprinting at least once a week at max v.
My 30 went form a 3.8 (hand timed with stopwatch in hand), to a 4 in two weeks when i focused mostly on bounding and jumping rather than sprinting. After 1 day of 30 m sprinting, I went back down to a 3.84 two days later.
Then one day I did deep squat jumps with 175 lbs (my max squat is prolly weak as hell), and I definitely felt faster. So yes it helps, but what I see a lot of people doing is focusing on the lifting and forgettiing that RFD cannot be trained for sprints by squatting.
Also, I read an article that I can’t find anymore that said sprinting and jumping was actually isometric rather than concentric.. Any thoughts on this?
If oyu think about it, all that force is being developed in only .2 seconds at the start and in a running vertical jump. Once that power has been generated at a specific joint angle, it’s over, you jump up (to a certain extent). Would it be fair to say there is at least some isometric stuff going on?