Magdalena Wajrak, Edith Cowan University

If you’ve been in the market for a new hair dryer, you’ve likely seen advertising for ionic ones. Some claim to produce negative ions in the millions – with or without the help of added minerals like tourmaline.

The broader claim is usually that these ions break water molecules into micro-droplets, resulting in faster drying and reducing frizz to give you super smooth, shiny-looking hair.

Are ionic hairdryers actually capable of doing what they claim? To understand this, we need to briefly delve into some fundamentals.

Wait, what is an ion?

All matter is composed of invisible building blocks called atoms. But they’re not the smallest things we know of. Atoms contain subatomic particles – protons, neutrons and electrons.

Every atom has a nucleus, a very dense centre made up of protons and neutrons. The number of protons determines what chemical element the atom is. Hydrogen has one proton, carbon has six, oxygen has eight, and so on. Molecules are groups of two or more atoms that form a chemical element; an oxygen molecule consists of two oxygen atoms, for example.

How does all this relate to ions? This is where electric charge comes in. All subatomic particles have an electric charge. Protons have a positive charge (+), electrons have a negative charge (-) and neutrons are, as the name suggests, neutral.

The nucleus has a positive charge overall, thanks to all the protons. Negatively charged electrons surround the nucleus because opposite charges attract. This is called electrostatic force, and it is this force that actually keeps the electrons from flying off away from the nucleus.

But electrostatic force is pretty weak. When materials touch or are rubbed together, we get the triboelectric effect – electrons can transfer from one surface to the other. This produces ions: positively or negatively charged atoms or molecules. For example, a negative oxygen ion is oxygen that’s gained an extra electron.

What do ions have to do with hair, then?

For the most part, hair is composed of large complex molecules called keratin proteins. In turn, keratin molecules are composed of various chemical groups, such as carboxyl groups, amino groups and disulfide groups. These can gain or lose electrons.

So, when hair is dried with hot air or is subjected to friction, keratin fibres lose electrons via the triboelectric effect – they become positively charged.

Remember electrostatic force? When hair strands are positively charged they push away from each other, and you get frizz and fly-aways.

This is why hairdryer manufacturers have come up with the idea to neutralise the positive charge with negative ions from the hairdryer. In theory, this should return the charges in your hair to neutral and therefore reduce frizz.

How do hair dryers generate negative ions?

This part is just physics. Although different manufacturers may use slightly different methods, most ionic hairdryers use high voltage applied to a fine wire inside the hairdryer.

This creates a very strong electric field near the outlet where the hot air is blowing. It sends electrons into the surrounding air, producing negatively charged ions – mostly oxygen and nitrogen. The airflow then carries these ions out with the hot air.

To increase the number of negative ions produced during this process, some ionic hairdryers incorporate a mineral called tourmaline which emits negative ions naturally.

Although theory does support the claim that negative ions might neutralise the electrostatic charge of positively charged hair, in practice the amount of ionisation generated by the ionic hairdryers is very small because they’re limited by the voltage applied (typically 1,600V).

Sure, you could generate a huge amount of negative ions with enough electricity, but that’s beyond the scope of an everyday beauty appliance.

The effect would likely be subtle

Overall, this means the effects from an ionic hair dryer would likely be subtle.

Other factors will play a more significant role in smoothness – such as your hair type, hair quality (whether it has been chemically damaged by bleaching or dyes) and what products have been used on the hair prior to drying.

There is also no scientific proof that ionic hairdryers dry hair faster by breaking up water droplets more efficiently, although some studies have demonstrated that ions enhance the evaporation rate of water.

Ultimately, before investing in a very expensive hair dryer, you may want to look at improving the health of your hair in general. Negative ions – while plausible in theory – can only take you so far.

Magdalena Wajrak, Senior Lecturer in Chemistry, Edith Cowan University

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

Read More........→April 15, 2026 Categories: How,Style

Hunter Bennett, Adelaide University

If you go to the gym often, you might have been told you shouldn’t lift weights in runners.

The common belief is it is bad for your performance and can lead to injuries.

But is this really the case? Let’s unpack the science.

What your feet are doing when you lift

Your feet are key to exercising safely and effectively.

When you walk and run, they act like a springs and help propel you forward with each step. Your feet also help you maintain balance by supporting your weight.

When you lift any amount of weight (for example, doing compound exercises such as squats) your feet are working hard to keep you stable – even if you’re not thinking much about them.

Researchers have also suggested having a stable foot helps you push more efficiently into the ground. This may increase the amount of weight you can safely lift.

But what you wear on your feet may also contribute to this.

Can’t I just wear runners?

Unsurprisingly, given their name, running shoes are designed specifically to improve your performance and protect your feet while running.

They generally have a raised heel, a thick, cushioned sole to absorb shock, and a “rocker” shape that helps you roll from your heel to your toe. These features help reduce the impact of running on your body.

But in the gym, this cushioned sole may absorb the force you create when lifting weights, making you feel less stable, strong, and powerful. This is likely why some people may say you shouldn’t lift weights in running shoes.

Some people may be concerned this can lead to weightlifting injuries.

One 2016 study found wearing running shoes for exercises like squats can change how your ankle and knee joints move. But there is no peer-reviewed evidence linking these changes to injury.

What are my other options?

Aside from running shoes, there are three other shoe types people generally wear while lifting weights: minimalist (sometimes called “barefoot”), flat or weightlifting shoes.

Minimalist shoes are designed to simulate being barefoot. They have thin soles with almost no cushioning, and aim to let the foot interact with the ground as if you were not wearing shoes at all. Flat sneakers designed for casual wear, such as Vans or Converse, also have thin soles without cushioning.

As a result, these types of shoes may be a good choice for lifting weights because they will be more stable than runners.

In contrast, weightlifting shoes are designed to improve how you perform in the gym.

They typically have a raised heel and a solid, stiff sole without any give, often made of wood or hard plastic. This helps you stay stable at the bottom of a deep squat, which is particuarly useful for movements such as squats, cleans and snatches.

But how do these different shoes stack up?

Studies looking at the impact of footwear on gym performance is largely limited to the squat and deadlift, probably because these are focused on leg strength.

One study from 2020 comparing running and weightlifting shoes found the latter helped people squat with a more upright torso and more flexibility in their knees.

This can take stress off the lower back and make your leg muscles work harder, which is the main purpose of the exercise.

Similarly, research from 2016 showed people wearing weightlifting shoes felt more stable when squatting. This suggests they may be a better option for that specific exercise.

A 2018 study focused on people performing deadlifts. It found running shoes reduced how quickly people could push force into the ground compared to when they wore only socks. This may suggest that they were more stable without running shoes.

However, this difference was small and has not been consistently replicated in other studies.

So what shoes should I wear?

That ultimately depends on your personal goals and situation.

Weightlifting shoes might be your best bet when doing squats. But if you mainly stick to deadlifts, flat shoes may slightly boost your performance. That is if your goal is to lift as much weight as possible.

However, if you are an Olympic weightlifter who needs to get into a deep squat position for competition, weightlifting shoes are the ideal option.

For everyone else, what shoes you wear may not matter as much. So wear whatever is most comfortable and keep lifting those weights.

Hunter Bennett, Lecturer in Exercise Science, Adelaide University