I race mountain bikes and I have had a number of races where I have been completely out of breath and unable to go faster because I feel like I am at my limit. I am experienced and I am a good bike handler with a very high level of fitness in both running and cycling. I have been training all winter, but this weekend I did a race and I came 38th out of 50. At the same race last year I came 6th and ahead of the guy who won it this year. I know my ability level and I can ride very fast at times. But this was staggeringly bad. I felt like I was going as hard as i could, even though I must have been going very slow looking at the times. It has happened in other races too but this weekend was by far the worst.

I always get nervous when I ride with other people too. Sometimes it feels like its not even me on the bike and I am a passenger to this feeling of not being able to keep up. I know its not a fitness thing as I am a fast runner and a strong road cyclist and I know I have very good bike handling skills. But sometimes it just doesn't feel like me when I try to go fast under pressure.

I can't swim and I get a similar feeling of being out of breath, despite having done little to no physical exertion, when I try. With all the work I have put in, this complete and seemingly inexplicable capitulation was pretty heartbreaking.

1 Answer 1


“Hitting the wall”, or "pinging" is colloquial for having your heart rate bouncing off your Max Heart Rate (MHR). Being overly out of breath and head-dizzy are symptoms.

“Bonking” is colloquial for when your muscles run out of glucose-etc. Your entire body aching – especially your shoulders – is a symptom.

These are two very distinct feelings; but are somewhat interrelated. Sounds like you're suffering from the first. In my experience the first can start to happen more dramatically (noticeably) as you get older – “older” as in 36yo mind you : /

I had the first example above happen so bad one time in Santa Cruz that I had to get off my bike and walk. I had had plenty of food, and absolutely knew myself – I knew I wasn't bonking and couldn't understand what was happening to me – but I pushed too hard for too long to try and keep up with an amazing athlete on a hill climb. This is colloquially called “exploding”. You see it all the time in professional bike races during hard climbing events. Once you “explode” you can't recover while still providing output to the bike. This happens easier as you get older – even though you think you are at exactly the same (or better) physical condition.

A third thing is ”heat exhaustion”. This is a whole 'nother animal, and the most dangerous of the lot. I've explored the depths of these three failure points quite a few times. It's good to know where they are, but to be sure, one day you may “take it to the next level” and be completely shocked by what your body is doing,even though you think you understand what these things are...

You need a heart rate monitor, and to review the breadcrumb heart rate data for a race on your computer and see exactly what your heat is doing when you feel that way. The numbers will be clear as day. Or you can just look at your wrist/stem when riding and SEE you're “pinging” off your MHR – and if you stay there for long, you'll feel that “explosion” coming - irretrievably out of breath and often dizziness.

“That's rodeo” as far as bicycle racing (sans downhill, in most cases) – scrunching up against a predetermined heart/work rate and staying there. The way this feels, as far as work output, can vary widely – hugely in fact – depending on altitude, food, sickness and countless other things – and especially nerves – but the numbers don't lie as far as optimizing your output.

Hope that helps.

Be careful. Genetic predisposition for heart problems may onset. A full checkup may be required – even if you're only 40-some years old. People die from heat attacks in their 40s – even athletes.

EDIT: One final thought – as a runner you probably understand clearly the notion of stride length. How extending your stride just slightly can drastically increase your speed for basically the same amount of work. And like rowing, or swimming, where getting that extra “reach” - even an inch – can really make all the difference in the world for max top-speed. I see breathing as exactly the same – especially road racing. Take a big breath right now. Then take another breath and exaggerate the total input – EXPAND the lungs. THAT right there – training yourself to do that all the time when riding at your predetermined heart rate, will effectively be like having the extra few inches of “reach”.

If you ride hard enough long enough – training – you just naturally acquire it. But understanding what the desired end-state condition “looks like”, can really help you get there ..faster.

When you “explode”, as I've call it, that whole process of breathing is out of sync with your body. To try best to work through an explosion in a race is exactly – precisely – directly – the art of breathing big and consistent, even though your body is saying you really don't need to – because it's overloaded and wants to make you slow the F' down.... it's making you hyperventilate with shorter 25% quick breaths.

  • Very informative, thank you. As you say its not bonking as the stages are short and this happens almost instantly. I think you may be on to something with the breathing. Its not something i ever focus on. As someone who has anxiety in other areas of life it affects me a lot and breathing better might help. I have been "in the zone" before and I havent had to think about anything while going very fast. Everything happens without thinking then and its a wonderful feeling. This was the antithesis of that. I am only 28 and there is no history of heart failure in my family.
    – Peter
    Aug 4, 2014 at 22:49

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