Bonk-proof your fuelling: what’s really going on to cause you to ‘bonk’ and how to avoid it

Shaken by a personal experience of that dreaded running on-empty feeling, Anita Bean goes in search of fuelling experts to find out what ‘bonking’ really means and how to avoid it

Male cyclist taking a break on the side of a country lane during a bike ride
(Image credit: Future)

It was a route I’d done plenty of times before. Normally, I’d stop halfway to have a drink and snack but this time I pushed on. After an hour and half of riding at a brisk pace, I wasn’t expecting my legs to feel so tired but I put it down to lack of recovery from a weights workout the previous day. Then, suddenly, without warning, I felt like I was cycling through treacle. Despite mustering up every bit of strength remaining, I had nothing left – the road ahead was starting to blur and I was barely holding a straight line. 

What was going on? I felt angry and emotional – with myself, the traffic, the potholes, other cyclists that overtook me. My heart rate was through the roof although I was barely moving. Was I having a heart attack? I pulled over and, with shaking hands, called my husband for help, something I had never done before. It went to voicemail. Tears were running down my face now. Not wanting to attract attention, I got back on my bike and attempted pedalling but managed only a few more metres. My legs felt like jelly. I pulled over again and tried to calm my breathing. That’s when I realised what was happening: I was suffering a ‘bonk’. Worse still, I had no fuel with me and needed to get home. 

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