Luckily I rarely get headaches, but it seems when I race I finish with a headache. I don’t get headaches ordinarily when riding, only in race conditions. I don’t use gels or add anything to water (in camelbak).

Wondered if it might be a symptom which could be commonly attributed to a lack of something in diet before race?

Had tuna steak + pasta with spinach yesterday evening, bowl of fruit & yoghurt for breakfast, two small raspberry jam sandwiches, banana, slice of lemon drizzle cake, & a snickers bar leading up to race.

Did wonder about lack of caffeine, no different after coffee post race.

Stress / blood pressure?

Dehydration?
Teeth grinding?

Sounds like dehydration to me. Make sure you’re well hydrated before you start the race rather than playing catch up whilst riding.

Sounds like dehydration to me.

+1

I love the way people assume it’s dehydration with absolutely no indication from the OP how much they are drinking or what the conditions of the race.

In my cycling experience it’s just as likely to be over-hydration if the person is drinking too much. I over-hydrated for years and got headaches which lasted for days until I discovered “Waterlogged” by Tim Noakes. This article gives you all you need to know to indicate if it’s over or under hydration.

Waterlogged – A Dogma-Shattering Book?

How tight/comfy is your helmet?
My road helmet has to be adjusted ‘just right’ to stop it causing headaches. One click too tight on the dial & it goes from comfy as a nice beanie to medieval torture device. I sometimes need to adjust it mid ride if I’m putting a lot of effort in presumably as my head swells slightly with the increased blood flow or something.

If this only occurs under race conditions, I’d put it down to a bit of self induced stress, nervous energy taking its toll and adding to your state of mind.

I occasionally get this I attributed the cause to various things.

Dehydration
Low blood sugar
Overheating
Tension (from the stress – so tense neck, teeth grinding, holding a stressful body position which creates tension in back)
Slightly too tight helmet/glasses (combined with being hot)
Pushing my body, pretty sure being able to taste blood at the end of TTs is not good.

Jonba, the blood thing is fine, I’m not a doctor but have looked into this myself,

Lack of fluids plus stress of competing

So fairly normal then? Think I’ll put it down to stress/tension more than anything. And not getting enough sleep the night before and/or possibly not quite managing to take it easy enough in the week leading up to the race.

Comparing my weekly riding with STW Forumites on Strava I usually end up feeling like I’m not pushing myself hard enough and taking things too easy in my guessed self-guided attempts at training – yes been reading Kryton’s threaad – and am also a sporadic/late starter to racing.