A new study has proved what many time triallists have long suspected: times are quicker in the evening than the morning.
And it’s not because the wind had dropped later in the day — the tests were done indoors.
Nine fit cyclists were timed over a short course that was just one km long. They performed the tests on two different occasions, at 8am and again at 6pm. Each time they rode, they had fasted so that any nutritional factors could be ruled out.
The riders came to the tests well rested and they had abstained from any caffeine or alcohol for 24 hours previously.
The researchers in Brazil asked them to ride 1k on a stationary bike, staying seated and letting the riders determine their own pace. Feedback on their time was given every 200 metres. Temperature and humidity were kept constant between tests.
The difference in results according to the time of the day was pretty significant. They clipped an average of 6.5 seconds off their times on the evening rides. That’s an improvement of very close to 7 per cent.
“This improved performance in the evening is in agreement with previous reports of better performance in the evening,” say the researchers.
The reasons are not clear, but subtle changes in metabolic and hormonal factors are thought to be involved.
One km is clearly not a long test, but a near 7 per cent improvement is one that many testers would spend many hours or plenty of money on bikes or kit to achieve.