A good warm up (WU) will help you get the best from the session, most people will go straight from their WU into the session, but I've found this not the best way to start this session. Whether it's a progressive WU or a specific WU, when you finish the WU stop for a few minutes, get off your bike, top up your bottle, go to the toilet, even sit down, then after a few minutes (3-5min) get back on the bike and then within a minute of getting back on your bike start your session, I've found the legs will feel far better with this time off the bike.
I found this out by being far too stubborn! I found quite a few times going straight from the WU into the session there was no way i could see the numbers (watts or HR) i wanted when doing a specific effort, so i climbed off having spat my dummy out, then sat around feeling sorry for myself for a while! then thought sod it lets try again, i got back on the turbo and straight into the session, straight away my legs felt totally different in a good way and i could easily achieve the numbers i wanted.
If you think about it this what you do after you have WUed up for a race, you sit around on the start line for a few minutes, you don't go straight from WU into the race, so this time off the bike during your training WU is getting you used to your event WU.
This could also help when training on the road, after WUing up take it really easy for a few minutes before starting your training again.
