Pilates Thoughtful Tuesday: Still, Sparkling… and What’s Really in the Glass?

Elegant restaurant table featuring curated water menu with still and sparkling selections

I was driving the other day, tuned into Radio 4 as usual. It’s one of my favourite classrooms. No effort required, just listen and learn. This time, the subject was water. Not just drinking water. The water industry. And somewhere along the way, we have now created something called a water sommelier.

Apparently, choosing water is no longer a simple decision between still or sparkling. There is now a full menu. A curated experience. A moment to pause and consider the origin, the mineral profile, the mouthfeel. Yes, mouthfeel. For water.

The programme was called Still Sparkling, which feels oddly perfect. It’s the question we all get asked in restaurants. But now that simple question has grown into something else entirely. In some places, you are handed a water list alongside the wine list. And not just a token choice. A proper selection. Bottles from different regions, with different characteristics, and sometimes prices that rival a decent bottle of wine.

It does make you stop and think. What actually makes “good” water good?

At its simplest, water is H2O. But of course, it’s never just that. Natural water contains dissolved minerals picked up as it travels through rock and soil, and these minerals are what give water its taste and, to a degree, its perceived quality.

The main ones you will hear about are calcium, magnesium, sodium and bicarbonate. Calcium and magnesium are often grouped together as hardness and tend to give water a fuller, sometimes slightly chalky taste. Magnesium can introduce a mild bitterness, while sodium softens the flavour and can make the water feel smoother, or slightly salty at higher levels. Bicarbonate plays a role in pH balance and can influence how clean or refreshing the water feels when you drink it.

There is even a way to measure this, and it takes the conversation out of opinion and into something more objective. Total Dissolved Solids, or TDS, is used to describe the combined amount of minerals dissolved in water. It is measured in milligrams per litre and gives a clear indication of how mineral-rich the water is. Very low TDS water, often seen in highly filtered or distilled water, can taste flat or empty because most of the minerals have been removed. At the other end of the scale, very high TDS water can feel heavy and overly mineralised, sometimes with a strong or slightly bitter taste depending on the mineral mix. Many people find that a moderate TDS level provides a more balanced taste, where the water feels clean but still has some body and character.

Then there is pH, which adds another layer to how we experience water. The pH scale measures how acidic or alkaline a substance is, with 7 considered neutral. Most drinking water sits somewhere between slightly acidic and slightly alkaline, depending on its source and treatment. Some bottled waters promote a higher alkaline level as a benefit, often suggesting improved hydration or health advantages. At the moment, there is limited strong evidence to support significant health benefits from alkaline water for the general population. What pH does influence more clearly is taste. Slightly alkaline water can feel smoother or softer, while more acidic water may taste sharper or crisper. So once again, what we describe as preference is often linked to measurable characteristics, even if we are not consciously aware of it.

Most restaurants will, quite rightly, offer tap water for free. It’s often presented as the sensible, grounded choice sitting quietly next to the theatrical arrival of imported bottled water. But once you start thinking about it, the obvious question appears. How clean is that tap water, and what has been done to it before it reaches the table? In the UK, tap water is highly regulated and generally very safe to drink, with strict standards set for microbial safety and chemical limits. However, safe does not mean untouched. By the time it arrives at the tap, it has often been treated, filtered, disinfected and adjusted to ensure it meets public health standards.

The most common treatment is chlorine, used to kill harmful bacteria and pathogens. Chlorine is effective, but it does change the taste and smell of water, giving that slightly sharp, almost swimming pool note that some people are very aware of. Then there is fluoride, which is added in some areas to help reduce tooth decay. Fluoride is a naturally occurring mineral, but when added to water supplies it becomes part of an ongoing public health discussion. Some see it as beneficial for dental health, while others question long-term exposure and whether it should be a matter of personal choice. From a taste perspective, both chlorine and fluoride can subtly alter the flavour of water, often flattening or masking its natural mineral character.

This brings us back to the idea of “good” water, because once you begin adding or removing elements, you are no longer just drinking what came from the ground. You are drinking something that has been engineered to be consistent, safe and reliable across a population. There is nothing inherently wrong with that, and in many ways it is one of the great public health achievements, but it does remove the individuality that people are now rediscovering through bottled water. In contrast, natural mineral waters are defined by what they contain at source, often protected from treatment processes that would alter their composition. The irony is that we pay for water to be stripped, cleaned and standardised, and then in another context we pay even more for water that has been left as close to its natural state as possible.

Temperature then enters the conversation, because even that is no longer simple. Cold water is often promoted as refreshing, especially after exercise, and it can help reduce core temperature more quickly. But you will also hear claims that very cold water is less beneficial or that refrigerating water somehow damages it. From a scientific perspective, water does not lose its structure or benefits simply by being chilled. However, temperature does influence how we experience water and how the body responds. Ice-cold water can cause slight constriction in the digestive system and may feel uncomfortable for some people, while room temperature water is often easier to drink in larger amounts and may support more consistent hydration. For Pilates, where the aim is controlled movement and steady breathing, room temperature water often sits more comfortably within the body. It is less about rules and more about what allows you to hydrate effectively without distraction.

And then, as always, we come back to perspective. We now have water menus, mineral breakdowns, temperature preferences, filtration systems and debates over additives, yet the core truth remains unchanged. Water is essential. It supports circulation, joint health, tissue quality and overall function. We can analyse it, market it and argue over it, but none of that changes its fundamental role.

Perhaps the more useful question is not whether your water is still, sparkling, filtered, chilled or mineral-rich, but whether you are actually paying attention to it at all. Are you drinking enough? Are you aware of what you are choosing and why? And are you treating water as something valuable, or just something that happens to appear when you turn on a tap?

Because in the end, the strange thing is not that water has become complicated. The strange thing is that something so simple, so vital and so constantly present can be so easily overlooked until someone puts it on a menu and gives it a price.

Research and references

World Health Organization. Guidelines for Drinking-water Quality, 4th Edition, 2017.https://www.who.int/publications/i/item/9789241549950

British Geological Survey. Mineral composition of natural waters.https://www.bgs.ac.uk

European Commission. Drinking Water Directive (EU) 2020/2184.https://eur-lex.europa.eu

U.S. Geological Survey. Hardness of Water and Total Dissolved Solids.https://www.usgs.gov

International Bottled Water Association. Bottled Water Basics.https://bottledwater.org