Getting a headache during or after exercise can be seriously frustrating – especially if you have kept hydrated to try and stop them from happening.

But why do these headaches occur? And does keeping hydrated make any difference?

What are exercise headaches?

Exercise headaches (also known as “exertional headaches”) are exactly what they sound like: headaches that occur either during, or after, exercise.

French doctor Jules Tinel first reported these headaches in the medical literature in 1932 and they’ve been a regular point of discussion since.

Exercise headaches commonly present as a throbbing pain on both sides of the head. They most often occur after strenuous exercise – although what is considered “strenuous” can differ between people, depending on their fitness levels. They can last anywhere from a few minutes to a couple of days.

Exercise headaches are thought to impact about 12% of adults, although this number varies from 1% all the way up to 26% across individual studies.

In most circumstances, these headaches are harmless and will resolve on their own, over time. Some research suggests you will stop getting them after a few months of starting a new type of workout.

But while they are usually harmless, they can sometimes signal an underlying condition that requires medical attention.

What causes exercise headaches?

Despite a good amount of research looking at exertional headaches, we don’t know their exact cause, but we do think we know why they occur.

The leading theory suggests they are caused by changes in blood flow to the brain. During intense exercise, blood vessels in the brain dilate, increasing blood flow and pressure, leading to pain.

Because long-term exercise improves our cardiovascular health, including our ability to dilate and constrict our blood vessels, this theory makes sense when we consider that exercise headaches tend to resolve themselves over time. This might explain why research suggests fitter people are less likely to get exercise headaches.

People with migraines appear more likely to experience exercise headaches, which are thought to be caused by this same mechanism.

Does heat and dehydration cause exercise headaches?

There is evidence suggesting that exercise headaches are more likely to occur in the heat.

Your brain cannot dissipate heat by sweating like the rest of your body can. So when it’s hot, your body has to increase blood flow to the brain to help bring down its temperature, which can increase pressure.

Similarly, exercise headaches also seem to get worse, and occur more often, when people are dehydrated.

However, we are not sure why this happens. Some research has shown that dehydration results in increased strain during exercise. As such, dehydration might not necessarily cause the headache, but make it more likely to occur.

Red flags: when to see a doctor

Most exercise headaches resolve themselves after a few hours and result in no lasting negative effects.

In some rare instances, they could be sign of something more serious occurring in the brain, such as a subarachnoid haemorrhage (a bleed between the brain and the tissues that cover it), reversible cerebral vasoconstriction syndrome (a spasming of blood vessels), cervical artery dissection (or tear), intracranial hypertension (pressure in the brain), or an infection.

See a doctor to rule out anything serious if:

• it’s your first exercise headache
• the headache is severe and sudden (also known as a thunderclap headache)
• it’s accompanied by other symptoms such as vision changes, confusion, or sensations of weakness
• you experience a stiff neck, nausea, or vomiting with your headache
• it lasts for more than 24 hours and doesn’t seem to be getting better.

Can you prevent exercise headaches?

There is no surefire way to prevent exercise headaches.

But a recent review suggests that ensuring you’re adequately hydrated and gradually warm-up to your desired exercise intensity can make them less likely to occur.

Beyond this, you may wish to keep your exercise intensity in a light-to moderate range for a couple of months. This will give your cardiovascular system some time to adapt before trying more strenuous exercise, hopefully reducing the likelihood of getting exercise headaches at all.

Exercise headaches are annoying, but are generally harmless and should subside on their own over time.

Hunter Bennett, Lecturer in Exercise Science, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Could a simple patch, inspired by the weight-loss drug Ozempic, really help you shed excess kilos without the pain and effort of an injection?

Promotions of these Ozempic-style, weight-loss patches are popping up online, promising dramatic results with little evidence to back their claims.

Personal recommendations for the patches are common. This includes from some “doctors” on social media. But independent fact checkers have shown these endorsements are AI-generated.

So, before you spend your money, here’s why you should think twice about buying a weight-loss patch.

What’s in them? Do they work?

Ozempic-style patches are also known as GLP-1 patches. But they do not contain any pharmaceutical ingredient from Ozempic (semaglutide) or related drugs such as Mounjaro (tirzepatide).

Instead, the Ozempic-style patches contain a mixture of herbal extracts including berberine, green tea (Camellia sinensis), the tropical fruit Garcinia cambogia and bitter orange (Citrus x aurantium L.).

There is some laboratory evidence that select compounds from berberine, the polyphenols in green tea extract and hydroxycitric acid from G. cambogia may have some effect. This includes suppressing appetite, lowering blood glucose (sugar) levels and playing a role in regulating fat metabolism to promote weight loss.

However, laboratory evidence doesn’t automatically translate to what happens in humans. In fact, recent evidence in humans shows these herbs have little effect on weight loss.

Let’s take berberine. Mostly, the evidence indicates that people who take it don’t lose a lot of weight. One scientific review showed that taking up to 3 grams daily for a year had only a small effect on weight and waist circumference.

Another review that analysed data from multiple studies found that up to 2.4g of green tea extract supplement daily for 13 weeks and more than 4g of G. cambogia daily for 17 weeks did not affect people’s weight.

For bitter orange extract, a daily dose of up to 54 milligrams of synephrine (a compound isolated from bitter orange extract) for eight weeks did not lead to weight loss.

It is important to note that all these studies are for oral formulations of herbal extracts, such as tablets or capsules, rather than for extracts delivered by patches.

Do they get through the skin?

Whether an extract in a weight-loss patch gets through the skin depends on how the extract was made.

Our skin is highly lipophilic, meaning it absorbs oily or fat-soluble chemicals, and blocks water-loving, or hydrophilic, substances.

So not all medicines can be delivered through the skin. Ozempic, for instance, is administered as an injection because the drug molecule in it is too big and water-loving to pass through the skin.

If the extracts in the patches are made using a water-based process, their ingredients are unlikely to pass through the skin and will simply sit inactive on your body until you remove the patch.

The next issue is that patches can only hold very little herbal extract. In the studies we discussed above, grams of material were needed to see any effect. In reality, Ozempic-style patches typically hold less than 0.1g of extract.

So, even if the ingredients get through the skin, these patches don’t contain enough to have any meaningful effect.

You can’t assume patches are safe

The Therapeutic Goods Administration regulates medical products in Australia, including herbal extracts.

For a herbal product to be permitted for sale in Australia it must be listed on the Australian Register of Therapeutic Goods. There are no Ozempic-style patches on the register.

This means the quality and safety of any patch you buy has not been assessed and cannot be guaranteed.

An Australian study found instances where contamination with undeclared plant materials, heavy metals and prescription drugs, such as warfarin, have been reported in unregistered herbal products. These contaminants are dangerous because they can potentially be absorbed through the skin, then circulate around the body.

In a nutshell

While the idea of Ozempic-style weight-loss patches might seem appealing, they do not work, and their safety is far from guaranteed.

Instead of wasting your money, speak to your doctor or pharmacist who can recommend proven treatments for weight loss. They can provide safe and effective options tailored to help you reach your health goal.

Nial Wheate, Professor, School of Natural Sciences, Macquarie University and Wai-Jo Jocelin Chan, Pharmacist and Lecturer, UNSW Sydney; University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.