Huge coffee mistake you’re making everyday

A doctor has warned that most Australians are drinking coffee in the wrong way and it can have dire consequences.

Welcome to Ask Doctor Zac, a weekly column from news.com.au. This week, Dr Zac Turner deep dives into the best – and worse – time to drink that cup of coffee.

QUESTION: Dear Dr Zac, I love coffee but I also know it can be a great stimulant to help me get through the day. Is there a science behind what time of the day I can have a coffee when it is most beneficial to give me that extra bit of zing in my step, whether it’s getting my work done, or going to the gym, or even staying awake at night during a movie? I’m keen for any information you can give me. – Joel, 33, Gawler SA

ANSWER: Hi Joel, Let me start with the hard truth: most people are drinking coffee at the absolute worst time of the day — and it’s sabotaging their energy without them even realising it.

Yes, I’m talking about that beloved first thing in the morning coffee. The sacred moment when bleary-eyed Australians stumble toward the kitchen like zombies hunting for espresso. But here’s the kicker — that cup might actually be setting you up for a massive crash before morning tea.

You’re drinking coffee too early — and here’s why that’s a problem

You see, your body already has its own built-in coffee machine. It’s called cortisol. Every morning, about 30–60 minutes before you wake up, your body starts pumping this natural energy hormone. By the time you’ve had a stretch and checked your phone, cortisol is peaking — meaning you’re already wired (or should be).

Now here’s where it gets messy: if you down a coffee during that cortisol surge, you’re stacking caffeine on top of your body’s natural stimulation. That might sound like a great energy hack, but in reality, it can cause jitteriness, anxiety, and over time … tolerance.

You might be drinking your coffee all wrong. Picture: iStock

That means your daily double shot is doing less and less for your focus and mood. And let’s not even talk about the stomach dramas.

Oh, and that midmorning slump? The one that hits like a bus around 10am? Blame early caffeine. When you drink coffee right after waking, there’s hardly any fatigue for it to block — so when the caffeine wears off, you fall off a chemical cliff.

Close-up image of woman texting and drinking coffee outdoors Picture: istock

The smarter time to sip

The golden window for your first coffee is 60 to 90 minutes after waking. Why?

• Cortisol has peaked and is gently declining, so caffeine won’t tip you over the edge.

• Adenosine (your body’s “tiredness” signal) has started to build — and caffeine can finally do its real job of blocking it.

Drink it then, and you’ll feel more alert, avoid the crash, and ride the caffeine wave like a pro.

But what if you hit the gym early?

Now, Joel — if you’re one of those rare people who enjoy exercising at sunrise (can’t relate, personally), you can bend the rules. Caffeine before training can boost endurance, motivation and power output — as long as you slept well. Just go easy on the dose. Even half a cup can do the trick.

No sleep? Be warned — early caffeine can block leftover adenosine too soon, setting you up for a post-gym nosedive. Sometimes, training without caffeine helps reset your body’s sensitivity and prevents dependency.

Early caffeine can block leftover adenosine too soon, setting you up for a post-gym nosedive. Picture: iStock

One more thing … stop sipping after 2pm

Caffeine has a half-life of about six hours — so that innocent 3pm flat white could still be messing with your sleep at 9pm. If you’re wondering why you’re wired at bedtime after one afternoon cup, now you know.

Final word

Your coffee isn’t the enemy — your timing is. Get it wrong and you’ll feel anxious, dependent, and crashy. Get it right, and your cup becomes a performance-enhancing, focus-boosting, feel-good tool.

So next time you roll out of bed and reach for the espresso machine — pause. Let your body wake up naturally first. Then let that coffee work with your biology, not against it.

Trust me, Joel — your 10am self will thank you.

Yours in better buzzes,

Dr Zac

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Dr Zac Turner is a medical practitioner specialising in preventive health and wellness. He has four health/medical degrees – Bachelor of Medicine/Bachelor of Surgery at the University of Sydney, Bachelor of Nursing at Central Queensland University, and Bachelor of Biomedical Science at the University of the Sunshine Coast. He is a registrar for the Australian College of Rural and Remote Medicine, and is completing a PhD in Biomedical Engineering (UNSW). Dr Zac is the medical director for his own holistic wellness medical clinics throughout Australia, Concierge Doctors.

Originally published as Huge coffee mistake you’re making everyday