Riding the morning after: How safe is hungover cycling really?

Have you ever got on your bike after a heavy night and wondered how safe it really is? Or perhaps it’s your favourite way to blow off the cobwebs on a Sunday morning.

Well, there’s a study for that. Published in the International Journal of Legal Medicine, the study was led by Dr Bruno Hartung of the University Clinic in Dusseldorf.

Researchers asked participants to carry out a number of cycling tests at various blood alcohol levels, allowing them to drink from 2pm to 11pm. After a night at the research centre, they were cruelly awakened at 8am and told to perform another cycling test, comparing their results to the evening before.

In the ‘postalcoholic’, or hungover, state, the cyclists had ‘significantly reduced practical ability’ - comparable to blood alcohol concentration of about 0.30g/kg.

But it didn’t seem to matter whether all the alcohol needed to be out of the cyclists’ system; those with and without residual blood alcohol levels were equally useless at riding.

The researchers concluded: “Instead, the side effects of the high amounts of alcohol that were consumed the night before are crucial.”

The same researchers (and likely the same participants) were behind another study we reported on which found that extremely drunk men may still be able to ride a bike in relative safety, while women cannot.

It found that while some men could still ride competently despite a high blood alcohol content, no woman was able to do so.

Among the reasons put forward as potential explanations are that men have less body fat than women, so females are more susceptible to the effects of alcohol, that men in general ride faster meaning their momentum helping them avoid obstacles more easily, and that irrespective of the influence of alcohol, women tend to be more respectful of other road users.

The study assessed 41 men and 37 women for their ability to ride a bike safely with various levels of alcohol in their bloodstream.

Subjects, aged between 18 and 53 in the case of the men and 18-43 for the women, were required to undertake a series of tests assessing their riding while sober, and then at various levels of blood alcohol content.

Those included riding straight ahead on a narrow, 45 metre track, riding while slaloming between poles placed 1.8 metres apart, riding clockwise around caps that decreased in space between them from 4 metres to 1.5 metres, and riding between movable plastic barrels spaced 1.2 metres apart.