Following on from the thread about disrupted sleep patterns after training (see 'Jamaican' thread). There isn't a lot of published research on this matter, though trawling through a few coaching websites reveals that its more common than you might imagine.
Terry is right that it's symptomatic of over training, but whereas overtraining and its adverse side effects takes time to build up, the sleepless nights we experience after a ride like saturday's, and often in my case after riding hard interval sessions, are more commonly in response to undergoing an excessive workload (in terms of volume, intensity or both) when your not used to pushing that hard. Early season rides are therefore perfect for disrupting your sleep as in most vcases your coming back off a quieter period or xmas/new year break.
Races, sportives and TTs will have a similar effect because on these you are again pushing harder than you normally would and in response your body goes into all sorts of heightened states in order to cope with the effort.
Continuous disruption to the sleep pattern will certainly suggest over training and you should be concerned about it, but after a ride like saturday's, you probably all noticed that you were back to normal on sunday night (unless you tore it up on a reliability trial), therefore nothing to worry about.
As you become an old git (like me) you take longer to recover from hard sessions anyway, and lack of sleep on certain nights is just another thing to factor into your training.
Dr Williams