As someone who has suffered from enxaquecas most of my life, I was not surprised when I experienced my first exercise or workout headache midway through a half-marathon.

The race conditions were hot and humid and I had not adequately hydrated prior to the starting line. By the time I realised what was going on, it was too late. The hydration and fuel I was feeding my body at mile eight, was not enough to combat the nagging ache in my head.

While this dor de cabeça was painful and annoying, I quickly realised that what I was feeling was not a migraine, rather a headache produced by the intensity of the exercise, environmental conditions, and lack of proper fuel.

Workout headache causes

Experts, including doctors and scientists, are not exactly sure what causes headaches triggered by strenuous exercises such as running, lifting weights, or intense cycling. Researchers believe the most likely theory is that blood vessels inside the skull become dilated during a strenuous activity. Others reckon a rapid drop in blood sugar could be the culprit.

But what they do know is that some headaches only occur with exertion, particularly with activities that involve tensing the abdominal muscles or increasing the pressure in the chest, both of which happen during strenuous exercise.

Exercise, or workout, headaches, as they are often called, are really part of what's medically known as primary exercise (exertional) headache. This is a rare type of headache that causes a throbbing head pain, during or after any form of sustained exertion.

They are commonly described as bilateral (on both sides of the head) and pulsating, according to the American Migraine Foundation. Primary exercise headache generally lasts from five minutes to 48 hours. They are more likely to occur in hot weather or at high altitude but can occur in any weather and at any altitude.

Dr Ehsan Ali, a GP in Beverly Hills, California, says there are several reasons people could experience headaches while working out. Dehydration is a common cause. And repeated jarring of your skull if you're running or jumping, along with loud music and sometimes bright or flashing exercise studio lights, are unlikely to help. Migraines are also a possibility, and especially prevalent in those with chronic migraines. Other, rare causes could include something as serious as aneurysms.

Since the exact cause of an exercise headache is unknown, Dr Ali says people who experience headaches from working out should most definitely seek medical attention and talk with their doctor right away if they've never had it checked out before.

The good news is that headaches caused by exercise tend to be self-limiting, which means they occur for a period of time, and then stop occurring. In the case of primary exercise headaches, that time period seems to be three to six months.

Because this is a limited time period, some experts advise avoiding the exercises or activities that are triggering the headaches and opting for less strenuous workouts.

If your doctor determines that you're not dealing with an underlying condition then you may want to try a few preventative measures before, during and after exercising.

Drink up

Dr Ali advises drinking plenty of water to stay hydrated. Eating regularly throughout the day, with a focus on fuelling your body in the hour or two leading up to your workouts, can help balance your blood sugar.

Don't turn up the heat

People who experience these headaches say they usually feel a throbbing head pain when they 'go hard' (often working out more intensely than normal), especially in hot weather or indoor environments that are warm. That's why it's a good idea to avoid exercising in extreme heat. Work out early in the morning before the temperature rises, or take your exercise regime to a facility with air conditioning.

Take it easier

Additionally, Dr Ali recommends resting and taking it easy. Remember, these headaches are associated with high levels of sustained exertion.

If you find that your intense sweat sessions are producing more headache pains than normal, try switching out your higher-intensity workouts in favour of lower-intensity activities for a while.

There are a number of things you can do in order to minimise these dores de cabeça and still be able to exercise. Try jogging or walking instead of running. Decrease the amount of weight you're lifting, or shorten your overall workout session. These minor adjustments may help you feel better and allow you to continue exercising. However, if this is a recurring experience, it's very important to speak with your doctor.