Not sure where Ewen gets his bus times from. Per Sunday timetable 44 going towards Edinburgh stops at Musselburgh Police Station at 7.18, 7.48, 8.18, 8.43, 9,15, etc. No 26 stops at same place at 5.56, 6.22, 6.42, 7.01, 7.21, 7.41 etc. The 44 service is running normally all day. The 26 is running all day but not between Levenhall and Port Seton (this impacts relay runners - it's hard to get to Seton Links by public transport)
If you follow Neil's advice best to walk from finish to Pinkie Road where you can catch either 44 or 26 back into Edinburgh.
There's more than one aspect to this. Take someone who gets nervous before races, and tends to run within himself. Psychological help may produce quite dramatic results - I saw an example of this where a girl went from being merely a good runner to winning races after sessions with a sport psychologist.
Another aspect is trying to fool the mind. The brain or central controller tends to keep energy in reserve and some techniques are aimed at overcoming this and using psychology to force the body to move faster. I'm wary of this but the approach has supporters.
And then sometimes the body may successfully override the mind, particularly if you're recovering from an injury. No matter how iron willed you are or how much you 'visualise' a favourable outcome the body adjusts and slows because it knows everything is not at full functionality.