We’re not necessarily trying to live to 100 here, though – we’re just trying to get through a long run without crapping ourselves or throwing up.

It’s worth flagging that not all ferments are created equal as not all ferments contain probiotics (the magic element that experts say can work wonders on our gut health and running-induced symptoms). Research published in 2019 found that “administration of selected anti-inflammatory probiotic strains have been linked to improved recovery from muscle-damaging exercise”. It concluded that the right type of ferments may be able to help reduce nausea and runners’ trots during or after long runs.

Scientists tested the impact of a yoghurt drink on 30 athletes. It showed positive results: training load increased and there was also a significant impact on VO2 max output (linked to efficiency and fatigue). That means (the albeit incredibly small sample of) athletes could work out longer and harder than usual. The authors reported that “probiotics appear to augment intestinal communication between the host immune system and commensal bacteria to establish mutualistic benefits”.

The evidence does seem to suggest that taking the right probiotics really might help to reduce cramps and diarrhoea in runners.

“I’ve taken Dr Tim Spector’s gut advice and started eating live yoghurt every day after running – here’s why”