Out of curiosity, how long between the end of warmup and beginning of work out?
My Recommendation would be taking as long as you need to feel recovered from your warmup and ready to go. However, dont take so long that you're already back to baseline. For strength and aerobic work ill go right into it. For alactic, lactic, or CP-battery work ill usually rest 3-5 minutes.
Fantastic article here, especially for people like me who are just getting into the world ups system