Season’s ending early august so im wondering, whats an ideal amount of rest time? I’ve ran a couple PBs lately and am paranoid about losing the speed/strength (yes i know losing some is normal) but for a 16 year old sprinter, what’s an optimal length of time to have a break from sprinting? 3 weeks fine?
3 weeks will do you no harm. You’ll lose speed over the winter anyway, so don’t worry about it.
Ya 3 weeks it is.
Actually I gain a lott of speed over the winter (indoor training) 
If your mind and body is well I would take 2 weeks off.
3 weeks off means off everything ?
Or just leave the speed and do just some tempo and bodybuilding ?
Most people will say 3 weeks off of everything (I think this is especially true for the highest level where it may be as long as 5-6 weeks from people I have talked to if they have been competing at the highest levels into September with many competitions). I always felt really odd not doing anything for more than a week and did some light warm-ups and strides on grass and light (essentially extended warm-up) lifting for a couple weeks.
Didn’t Ben used to take a full month off, or am I mistaken?
It depends on what you mean by ‘off’. Charlie’s DVD explains how an off period should be structured and why.