CYCLING PERFORMANCE TIPS
A: You probably have Effort Headaches. Although there can be many aggravators (stress & lack of sleep, to name two), it is unlikely that what you are eating is the culprit. You might try taking 600 mg of ibuprofen before your next ride to see if that will take care of it prophylactically.
Exertional headaches have be recognized for many years and are usually associated with such activities as weight lifting and wrestling (Level 4 evidence). Usually the athlete will describe a straining or Valsalva type exertion that leads to the sudden onset of a severe throbbing pain in the occipital region. This severe pain lasts for a few minutes and is replaced by a dull aching pain that may last for hours. The pain recurs when the patient exerts him/herself again. When you see the patient there are no neurological findings and if the headache is gone the patient usually appears well.
It is felt that the etiology of these headaches is vascular, possibly due to exertional increases cerebral arterial pressure, causing the pain-sensitive venous sinuses at the base of the brain to dilate. MacDougall demonstrated that during maximal lifts, the systolic blood pressure can reach levels above 400 mm Hg and the diastolic pressure can top 300 mm,Hg. (Level 3 evidence) Angiographic studies of both benign exertional and benign sex headaches have demonstrated arterial spasm, further implicating the vascular tree as the basis of these conditions (Level 3 evidence). Despite the fact the headaches are throbbing in nature and that intravenous dihydroergotamine mesylate can relieve them, there is no demonstrated association with migraine.
An important condition in the differential diagnosis of this sort of headache is Subarachnoid Headache. These headaches can be managed acutely with NSAIDs. The studies looking at treatment usually used Indomethacin, but they are older studies, so presumably the newer NSAIDs would work as well without the side effects of indomethacin. Exertional headaches of this type tend to recur over weeks to months when the activity is repeated. Gradually they subside, although they have persisted for years. Once gone the activity can be resumed using the maxim "start low and go slow".
These are the most commonly encountered headaches associated with exercise. A study from New Zealand involving 129 university athletes demonstrated that effort headaches were the most commonly recorded at 60%, followed by post traumatic headaches (22%), effort migraines (9%), and trauma-induced migraines (6%) (Level 3 evidence). These headaches are usually described as a throbbing, mild to severe pain, occurring after maximal or sub maximal aerobic exercise. These headaches may last up to several hours and are more common in women. They may have a migraine prodrome, and are more frequent in hot weather. Not unexpectedly they considered a variant of benign sexual headache, with both occasionally seen in the same individual. ( J Neurol Neurosurg Psychiatry 1991 May;54(5):417-21 Department of Neurology, Royal Perth Hospital, Western Australia).
Effort headache can be treated with NSAIDs, and most NSAIDs should work (Level 4 evidence). Anti-migraine medications have also been used with success. NSAIDs given before exercise may serve a prophylactic function. Obviously anti-migraine therapy with vasoconstricting effects is not recommended prior to aerobic exercise.
When a patient presents with exercise induced headache (just as with any other type of headache) it is important to watch for "red flags" which might indicate this is NOT just an effort headache. Red flags include: