She came to her Roadmap Call complaining of afternoon energy crashes, persistent brain fog, and a vague sense of heaviness that had been with her for months. She was sleeping reasonably well. Her nutrition was solid. She was training consistently.
One of the first things I asked was how much water she drank in a day.
She thought about it. “Maybe two or three glasses? I’m not really a big drinker. I don’t feel that thirsty.”
That last sentence, ‘I don’t feel that thirsty’, is exactly the problem.
After 40, the body’s thirst signalling becomes less reliable. Oestrogen plays a role in fluid regulation and in the sensitivity of the receptors that tell your brain you need water. As oestrogen declines, those signals weaken. You can be running at a significant hydration deficit, enough for it to affect your energy, your cognitive function, your metabolism, your digestion, your skin, and your hormones, and not feel particularly thirsty at all.
Hydration is one of the most underrated and most commonly overlooked pieces of the health puzzle for women in midlife. And the good news is that it is also one of the most immediate and most accessible things you can address. The results are often felt within days.
What Water Actually Does in the Body
Water is not just a drink. It is the medium in which virtually every biological process in the body takes place.
At the most basic level, water transports nutrients to cells and waste products away from them. It regulates body temperature through sweat and respiration. It lubricates joints and cushions organs. It supports kidney function and the elimination of the metabolic by-products that accumulate when the body is working hard.
But its roles go further than most people realise:
- Metabolism: every chemical reaction involved in energy production requires water as its medium. Even mild dehydration, as little as one to two percent of body weight, measurably reduces metabolic efficiency and slows energy production at the cellular level
- Digestion: water is essential for the production of digestive enzymes and the movement of food through the digestive tract. Chronic dehydration is one of the most common and most overlooked causes of constipation, bloating, and sluggish digestion
- Detoxification: the liver and kidneys, the body’s primary detoxification organs, require adequate water to filter and eliminate waste products, excess hormones, and environmental toxins. Dehydration slows this process, increasing the circulating load of compounds the body is trying to clear
- Hormone transport: hormones travel through the bloodstream, which is approximately 90 percent water. Dehydration thickens the blood, reduces circulation, and impairs the delivery of hormonal signals to target cells
- Appetite regulation: the brain’s hunger and thirst centres sit close together and their signals can be misread. Mild dehydration is frequently interpreted as hunger, driving unnecessary caloric intake. Drinking a glass of water before meals has been shown in research to reduce caloric intake by an average of 13 percent
- Cognitive function: the brain is approximately 75 percent water. Even mild dehydration produces measurable reductions in concentration, short-term memory, reaction time, and mood, which is why the brain fog and afternoon energy dips that many women attribute to hormones are sometimes, in part, a water problem
Why Hydration Changes After 40
Several factors make adequate hydration both more important and more challenging after 40.
Declining oestrogen affects fluid regulation
Oestrogen influences the activity of antidiuretic hormone, the hormone that tells the kidneys how much water to retain. As oestrogen declines, this regulation becomes less efficient, meaning the body may excrete more water than it should and hold onto less than it needs. Oestrogen also influences the sensitivity of the receptors in the brain that signal thirst, so as levels fall, the thirst mechanism becomes less responsive. The result is a body that is losing water more readily and asking for it less urgently.
Hot flushes and night sweats increase fluid loss
Each hot flush involves the body attempting to cool itself through increased perspiration. Women experiencing frequent hot flushes or night sweats are losing meaningful amounts of fluid throughout the day and night, often without replacing it, because the thirst signal that would normally prompt drinking is already less reliable.
Caffeine and alcohol increase fluid loss
Both caffeine and alcohol are diuretics, they increase urine output and accelerate fluid loss. For women who rely on coffee to manage energy dips (which are themselves sometimes a sign of dehydration) or alcohol to wind down in the evening, the diuretic effect compounds the existing hydration challenge. Each cup of coffee or glass of wine warrants an additional glass of water to compensate.
Muscle loss changes the body’s water storage
Muscle tissue holds significantly more water than fat tissue, approximately three grams of water per gram of muscle glycogen. As muscle mass declines with age, the body’s overall water storage capacity decreases, making it more vulnerable to the effects of even mild dehydration. This is another compelling argument for the muscle-building focus of the Strong Calm Lean Method, more muscle means better hydration resilience.
What Dehydration Looks Like After 40
Because thirst is an unreliable signal at this life stage, it helps to know the other signs that your body is running low on water:
- Urine that is dark yellow or amber rather than pale straw-coloured, the most reliable daily indicator of hydration status
- Afternoon energy crashes that hit regardless of sleep quality
- Brain fog, difficulty concentrating, or a sense of mental sluggishness
- Headaches, particularly in the afternoon
- Constipation or sluggish digestion
- Dry skin, lips, or eyes
- Muscle cramps or a sense of physical heaviness
- Hunger that arrives soon after eating, which may actually be thirst
- Low mood or irritability without a clear external cause
How Much Water Do You Actually Need?
The ‘eight glasses a day’ rule is a reasonable starting point but is not personalised to body size, activity level, climate, or the specific factors that affect fluid loss after 40.
A more useful target for active women over 40 is approximately 35 millilitres per kilogram of body weight per day as a baseline, more on days of intense training, in hot weather, or when experiencing hot flushes. For a 65kg woman, that is approximately 2.3 litres. For a 75kg woman, approximately 2.6 litres. This includes water from food, fruits and vegetables contribute meaningfully to daily fluid intake, but most of it needs to come from what you drink.
The simplest daily check: your urine should be pale straw-coloured for the majority of the day. Consistently dark urine is a clear signal to drink more.
How to Drink It – Sipping Beats Skulling
How you drink your water matters as much as how much you drink. The body can only absorb and retain a certain amount of fluid at a time, drinking large quantities in one go sends much of it straight through, which is why some women who drink plenty of water are still frequently in the bathroom and still not feeling hydrated.
If you find yourself constantly needing the toilet, this is often a sign that the water isn’t getting into your cells, it’s simply passing through. Rapidly drinking large amounts can also temporarily dilute and flush out electrolytes, the minerals your body needs to actually move water into cells where it can do its work.
The most effective approach is to sip water slowly and consistently throughout the day, small amounts regularly, rather than large amounts occasionally. Keep a water bottle visible and accessible, take regular small sips, and pair your water intake with adequate electrolytes (particularly sodium, potassium, and magnesium) to support cellular absorption. A small pinch of Celtic sea salt in your morning water or a clean electrolyte supplement can make a meaningful difference to how well your body actually uses the water you give it.
Filtered water is the first recommendation, and it’s worth understanding why. Research has detected a range of hormone-disrupting chemicals in tap water supplies, including synthetic oestrogens such as 17β-estradiol and 17α-ethynylestradiol, oestrogens that enter the water supply through the excretion of contraceptive pills and hormone replacement therapies, as well as BPA (bisphenol A) from plastics and pesticide residues. These compounds, known as xenoestrogens (xeno meaning foreign), can mimic natural oestrogen in the body and interfere with hormonal signalling. Conventional water treatment processes often cannot fully remove them. For women already navigating the hormonal complexity of perimenopause and post-menopause, minimising this additional oestrogenic load is a sensible precaution. A good quality water filter is a meaningful investment, look for one that removes contaminants but also adds back in the essential minerals your body needs. The filter we use at home is Waterco, it filters out the nasties while retaining and restoring beneficial minerals. You can find it here: https://bit.ly/3QRmUxd
Herbal teas count toward your daily fluid intake and offer additional benefits depending on the blend, chamomile for sleep support, peppermint for digestion, spearmint which some research suggests may support androgen balance in women.
Electrolytes become more important for women over 40, particularly those who exercise regularly, experience frequent hot flushes, or eat a whole-food diet lower in processed sodium. Electrolytes, sodium, potassium, magnesium, and calcium, are minerals that carry electrical charges and govern how water moves in and out of cells. Without adequate electrolytes, drinking more water alone does not fully resolve dehydration. A small pinch of Celtic sea salt in your morning water, coconut water post-training, or a clean electrolyte supplement are practical options.
Coffee and alcohol: both have diuretic effects. Enjoy them, but compensate with additional water. A practical rule: one extra glass of water for every coffee or alcoholic drink.
Sugary drinks and fruit juices: these contribute fluid but also spike blood sugar and add calories without meaningful nutritional benefit. Whole fruit is a far better choice, it delivers water, fibre, and nutrients together in a form the body handles more efficiently.
Simple Habits That Make Hydration Effortless
- Start with water before coffee: a large glass of water first thing anchors a hydration habit before the day creates any obstacles to it
- Keep a water bottle visible at your desk or in your bag: proximity is one of the most effective behavioural nudges for drinking more water. If it’s in front of you, you drink it
- Eat your water: cucumber, celery, watermelon, strawberries, zucchini, lettuce, and oranges are all more than 90 percent water. Building meals around vegetables and fruit contributes meaningfully to daily fluid intake
- Drink a glass before each meal: this supports appetite regulation, aids digestion, and creates a consistent hydration anchor throughout the day
- Set a gentle reminder if needed: particularly useful in the first few weeks of building a hydration habit, until drinking more water becomes automatic
- Add natural flavour if plain water feels uninspiring: a slice of lemon, cucumber, or fresh mint makes water more appealing without adding sugar or compromising its hydrating effect
The Strong Calm Lean Connection
Adequate hydration supports every pillar of the Strong Calm Lean Method. It supports the muscle function and recovery that strength training depends on. It aids the nutrient absorption that makes protein intake effective. It supports the liver’s role in metabolising and clearing hormones, including excess cortisol and oestrogen. It improves sleep quality by reducing the frequency of night waking. And a well-hydrated brain is simply better at everything, more focused, more emotionally resilient, and more capable of making the choices that support long-term health.
It is the simplest, cheapest, and most immediate lever available. And most women over 40 are not pulling it nearly enough.
If you’d love a personalised approach to your energy, body composition, and overall wellbeing, one that addresses the full picture, not just individual pieces, I’d love to hear what’s going on for you.
Book a complimentary Roadmap Call and let’s talk. I’ll listen to what’s happening in your unique physiology, and if I feel I can help, I’ll share the options to work with me inside the Strong Calm Lean Method. It’s a no-pressure conversation, and you’ll walk away with clarity and value either way.