Headache after Mountain biking?

Any ideas? Im new at Mountain biking, and lately whenever I go biking in the morning, I notice Ive got a headache that same afternoon. It's a really weird headache. Low in the back of my head, not pounding but a little light sensitive and almost totally reisistant to advil!

I know that dehydration can cause headaches, but I feel like Ive had enough extra water! (750ml during the 1.5 hour ride)

Im not on really really rough trails and not going over jumps or anything! Maybe my body posture is a bit off and Im straining my neck.

Any ideas!! thanks so much!

Does anyone else get this?

This could be caused by one or a combination of things,
1) Neck muscles not use to having a helmet on your head.
2) Caffeine, coffee good morning drink but can cause strange things to happen to some people who drink it and exercise afterward.
3) Dehydration, hydration needs to be a concern all the time not just a few minutes before, during and after a ride.

If you can try aspirin instead of advil, ibuprofen and acetaminophen products just never seemed to work as well as plain old aspirin for me.

When I get headaches, its generally after a hard effort in the heat. Most likely the beginnings of heat exhaustion.

Dehydration is also a possibility. 1.5 hours is a long time, and 750ml isn't much fluid. Even at a moderate pace, I'll sweat out 1300 ml per hour. At race pace in the heat, more than 2100 ml per hour. (as measured by scientists in Gatorade's basement lab).
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Edit: Another possibility is blood sugar issues. When I do get the headaches, its possible that I've let myself get too close to depletion (bonk). I recall that my dad used to get headaches if he went too long without eating. I wouldn't think 1.5 hours is long enough to do that, but everybody is different.

Your headache could be due to several reasons. It could be aggravated by your riding posture, or you may have pinched a nerve or blood vessel. Do you frequently get headaches?

First, though, I think you should look at how much fluid you're consuming. Unless the you're doing an easy ride in cool weather and prehydrated properly before the ride, I'd say you're intake is too low. 750ml equates to 25oz. On a similar length road ride in fair weather, I'll prehydrate, consume at least 44oz during the ride, and hydrate more after.

I wouldn't say that that's enough water (but then gain I drink an obscene amount), try upping your intake, throughout the day so you're not playing catch up in the morning.

It could be from shock riding up your arms, through shoulders and into the neck. Try to keep your elbows slightly bent to absorb shock better.

Good luck!

When it is cold enough i get headaches too, maybe that is your problem?

Sorry i didn't really answer your question it was the best i could do =P

Try Gatorade and Excedrin post ride, and work on your posture while riding. You could also take your rides at a different time of day just to see if there's any changes.

If I ever get a headache from doing something, I stop doing it.

take potassium ....it works for me on 50 mile rides