How To Stay Hydrated When You’re a Women Over 40
Feeling Like a Melting Ice Cream Cone on Your Summer Runs? 🥵 Let’s Do a Deep Dive on Your Hydration.
We’re deep into summer, and the heat is on. I’ve been getting a ton of messages from my clients, and the theme is clear. One woman told me last week, "I feel like I'm doing everything right—I'm drinking a ton of water, but an hour into my workout, I'm dizzy, my stomach is sloshing, and I have zero power. What is going on?"
If this sounds familiar, I want you to know two things: 1) You are NOT alone, and 2) There is a clear, scientific reason this is happening.
If you're a woman over 40, the generic, outdated advice you've heard for years just doesn't apply. Your body is not a small man. So, let's toss that old playbook in the bin, have a laugh about how wrong it was, and build you a new one based on your incredible female physiology.
Why Your Body's A/C Unit Has a "Unique" (and Annoying) Setting ⚙️
First, let's talk about cooling down. When you exercise, your body is a furnace, and it needs to get rid of heat. It does this in two main ways: sending blood to the skin (vasodilation) and sweating.
Here’s where it gets interesting. Men tend to start sweating almost immediately. It’s their go-to cooling strategy. Your body, however, is a bit more strategic. It relies on vasodilation first, pushing blood to your skin to try and cool you down. You only start to sweat profusely once you're already quite warm.
The consequence? You can have a higher core temperature at a lower level of dehydration than a man. You're essentially cooking from the inside out before your primary cooling mechanism (sweat) fully kicks in. This puts you at a much greater risk for heat strain and that "I've hit a wall" feeling.
The Hormone Factor: Your Own Personal Heatwave 🔥
Now, let's layer on the fun of being a woman in your 40s and beyond: hormones. They don't just affect your mood; they are master-regulators of your internal systems, including fluid balance.
If you’re still cycling: The week before your period (the luteal phase) is a game-changer. The rise in progesterone increases your core body temperature. But that's not all—progesterone also battles it out with aldosterone, the hormone that tells your body to hang onto sodium. Progesterone usually wins, meaning you lose more sodium in your sweat and urine. You're starting your workout hotter and primed to lose more of the exact electrolyte you need for hydration.
If you’re in perimenopause or menopause: The fluctuating and eventual decline of estrogen throws a wrench in everything. Estrogen helps manage your body's "set point" for temperature and fluids. Without its steadying influence, your internal thermostat goes haywire. This means you might overheat faster and your body's cues for thirst and fluid balance can become less reliable.
The Gut Check: Why Your Stomach Revolts 🤢
Ever feel that sloshing, cramping, or bloating during a hot workout? It’s not just you. This is a critical piece of the puzzle.
When you exercise intensely, your body goes into "fight or flight" mode. It shunts blood away from your gut—by up to 80%!—and sends it to your working muscles and skin. This dramatically slows down digestion and absorption.
Your gut becomes incredibly sensitive. If you dump something in there that it can't process easily (like plain water or a super sugary drink), it’s going to rebel. The drink will just sit there, pulling more fluid into the gut to try and dilute it, making you feel bloated and, ironically, even more dehydrated at a cellular level.
The "Just Drink Water" Myth and the Danger of Hyponatremia ⚠️
This brings us to the most critical—and most often ignored—piece of hydration advice for women. As we established, when you sweat, you lose both water and sodium.
If you diligently chug plain water, you're replacing the water but further diluting your blood's sodium concentration. This is hyponatremia, and it's far more common in women than men. In fact, studies on endurance athletes often show men finishing races with high blood sodium levels, while women are more likely to finish with normal or dangerously low levels.
Early signs of hyponatremia can look a lot like dehydration, but with a key difference: bloating and puffiness.
Nausea and vomiting
Headache
Feeling bloated or "sloshy"
Swollen hands and feet (is your ring suddenly tight?)
Confusion and dizziness
It’s essential to recognise these signs and understand that the solution isn't more water—it's sodium.
Drink to Thirst or on a Schedule? It's Time to Decide ⏰
This is your personalised strategy guide. Based on your physiology and situation, choose your camp.
Your Scheduled Starting Point: Aim for ~10 ml of fluid per kg of body weight per hour. For a 140 lb (64 kg) woman, that’s about 640 ml/hour (a 22 oz bottle). This is your baseline—adjust as you learn your body's needs.
Building the Perfect Sports Drink (No Lab Coat Required!) 👩🔬
Your hydration drink should do one thing perfectly: hydrate you. It is NOT your workout fuel.
What you NEED:
Sodium: The absolute king of hydration. It helps shuttle water into your cells and keeps your fluid levels balanced.
Glucose + Sucrose (a little!): A small amount of these sugars (a 2-4% solution) acts like an express pass, opening a special channel to pull sodium and water from your gut into your bloodstream much faster than plain water ever could.
What to AVOID:
High-Carb Mixes & Sugary Drinks: These are "hypertonic," meaning they're more concentrated than your blood. They sit in your sensitive gut, pulling water IN and causing that sloshing, bloating mess.
Maltodextrin: This is a tricky one. While it doesn't seem concentrated at first, your gut has to break it down, which can slow fluid absorption and cause distress, especially for women. I advise most of my clients to steer clear.
Your Official Heat-Proof Hydration Game Plan 🏆
Ready to put it all together? Here's your plan for success.
Hydrate Before You Start: Don't go into a workout dehydrated. Sip on water with a pinch of salt and a squeeze of lemon throughout the day.
Embrace the Salt: On hot days or for any session over an hour, plain water is banned. Use a properly formulated hydration mix.
Separate Hydration from Fuel: Sip your low-carb electrolyte drink for hydration. Eat your fuel (gels, chews, real food) separately. This keeps your gut happy.
Practice Everything: Never, ever try something new on race day. Use your training sessions to dial in your exact hydration and nutrition plan.
Pro-Tip for a Hot Event: If you know you have a big race or event coming up in the heat, consider supplementing with L-glutamine (5g a day) for the seven days leading up to it. It can help improve your gut's integrity and reduce the effects of heat strain.
You are not fighting your body. You're learning its language. By understanding these principles, you can work with your amazing physiology to feel powerful in any weather.
You've got this. 💪