Staying on top of your hydration all year round means you’ll ultimately perform better and get more out of each training session, which will pay dividends when the event you’re training for comes around.
Hydration is naturally a hot topic of conversation when you’re training during the warmer summer months or during indoor training sessions, when your sweat rate is more noticeable.
However, the need to properly hydrate doesn’t go away during your training in the cooler winter months and we’ve asked Precision Hydration founder and Sports Scientist Andy Blow whether there’s any advantage to drinking hot drinks in cold weather...
What are the benefits of drinking hot drinks in cold weather?
Hydration should still be a consideration during winter months as you’ll still be sweating (albeit obviously not to the same extent as in the summer) and a bigger issue might be losing fluids through peeing. A condition known as cold diuresis causes you to pee more in very cold environments as your blood volume moves to the core of your body, so the arterial cells of the kidneys recognize an increase in blood pressure and signal to the kidneys that they need to “dump” fluid through increased urine production.
Much of the scientific research looking at environmental temperature, beverage temperature and performance have focused on how cold drinks can enhance performance in hot conditions (the general consensus seems to be that they do help a very small amount compared to room temperature fluids).
Research looking at the effects of hot drinks when training in cold weather is thin on the ground, so it’s important to draw more heavily on experience and common sense.
The two most likely benefits of drinking hot drinks in cold environments are...
1) Encourage you to drink more than you otherwise would
This is principally because taking in ice cold drinks in already frigid conditions is pretty unpleasant and discourages you from drinking at times when you should actively be keeping your fluid levels topped up.
Whilst the overall risks posed by dehydration are less prevalent in the cold than when it's stinking hot, they definitely do still exist due to the aforementioned cold diuresis and the fact you’ll still be sweating (even if you don’t notice it as much).
You lose a surprising amount of sweat if you go out all bundled up in multiple clothing layers and the drier air can often contribute to losing more fluid through your respiratory tract.
As a result, do whatever you can to make the idea of drinking more appealing and that includes using hot drinks when you can.
2) Hot drinks are a huge morale-booster in cold conditions!
Outside of sporting situations, the motivating and soothing effects of hot drinks in cold weather are so universal they're effectively taken for granted in our ‘put the kettle on’ culture. I don’t think it’s too much of a stretch to suggest that that positivity can’t be transferred to a boost in athletic performance, even if it's only having a placebo effect.
How to use hot drinks effectively during cold training sessions
So, if hot drinks are a useful asset in the cold, the next question is 'how do you access them efficiently when training?'
- Plan hot drink stops into training runs, ultra-distances races and FKT attempts
If you're having to be self-sufficient, your options are cut down to either carrying an insulated drinking vessel or stopping somewhere that can provide a hot drink.
Stopping is clearly not an ideal option in all but the very longest of ultra distance races, but it can work okay in some training circumstances. If you can, maybe factor in a stop at a coffee shop on your route if possible!
If a coffee shop stop isn’t realistic, it can be worth ‘stashing’ a couple of hot thermos drinks just off the trail in advance if you’re doing a long adventure run or an FKT attempt, while you can ‘stash’ them for later when doing an out-and-back training run.
Alternatively, during training sessions, races or FKT attempts where you can have a support crew looking after your needs, it becomes relatively easy to take on hot drinks as the team can carry flasks or warm up your drinks for you. The main thing your crew really need to be aware of is making sure they don’t 'over deliver' and provide scalding hot liquids that'll burn your mouth if you drink them too quickly!
- Carry hot drinks with you
When it's not convenient to stop, there are a few options for carrying hot drinks with you.
The first (and best in terms of keeping the drinks hot) is to use a double-walled, insulated flask. Durable stainless steel ones are best for use in outdoor sporting situations and many of these will keep drinks pretty damn hot for up to 24 hours, especially if you take the time to pre-heat them properly before filling.
The downsides to a proper flask are that they often require two hands to unscrew the lids and they're heavy, so they're not very compatible with drinking on the move at speed. They’re also not usually a particularly good fit in running waist packs.
How to carry hot fluids during cold training runs
I did use stainless steel flasks when I was cross-country skiing as nothing else could really keep liquids hot in the snow! I'd either carry them in a backpack or stash them close to the tracks when we were doing intervals or sessions on a looped course.
In reality, you’ll be lucky to keep a drink anything more than lukewarm for more than about an hour or so in a plastic bottle on the coldest of days. However, that ought to be enough time to get through the 16-24oz they usually contain and give you a bit of a boost early on, when you're trying to convince yourself to brave it and stay out for a few more hours…
When running, carrying hot drinks can be very tricky if you’re not carrying a backpack or bottle holder in which to store a flask or insulated bottle. But this is maybe not such a problem as most normal training runs are relatively short and internal heat production is pretty high when running hard.
One potentially useful bit of kit that I picked up years ago when in Switzerland doing some cross-country skiing and that I've used on some of my longer winter runs back in the UK is an insulated waist pack.
It's basically a 32oz padded reservoir, built directly into a fanny pack, with a drinking valve mounted on the side. It’s acceptably comfortable to wear (given that it’s pretty heavy when full) and keeps drinks warm for a couple of hours, which covers you for a decent winter trail run at least. It does need cleaning out thoroughly post-run to avoid developing new bacterial life forms in the intervals between uses...
What is the best hot beverage to drink during training/events?
I think the main consideration here should be personal preference and taste. After all, if the key benefits are encouraging you to drink more and a morale boost, whatever you drink needs to be tasty.
I’ve heard of some athletes using hot chocolate and that's obviously got the added benefit of providing a sugar boost, but if it’s really milky it might not go down too well if you’re working hard.
Whilst hot alcoholic drinks like gluhwein, vin chaud, mulled wine or cider are ever so drinkable in subzero conditions, I’d hesitate to recommend them from a performance point of view)!
Out of curiosity, I recently tried using our Precision Hydration all-natural drink mixes and low-calorie effervescent tablets in hot water during some cold training sessions and was pretty pleased with the results.
The drink mixes (which contain some sugar) are definitely my favourite of the two options - maybe because you do tend to burn through more glucose when it’s very cold - but the tablets have the benefit of dissolving amazing quickly when dropped into an insulated bottle of hot water.
The other possible benefit of using Precision Hydration in your bottles or hydration pack when it's below freezing is that the electrolytes will lower the freezing point of the fluid, making it less likely that your bottle (or hydration feed tube) will ice up!
If you're reading this from somewhere cold, I hope it's helpful. Chin up, it'll be summer soon...
We hope you find this useful as you look to perform at your best in cold weather. If you have any questions about hydration at all, feel free to email hello@precisionhydration.com or book a free one-to-one video call with a member of the team.
If you’d like to start to understand your own individual hydration needs, take this free online Sweat Test to get some personalized hydration advice. And use the code PATH15 at precisionhydration.com to get 15% off your first order of electrolyte supplements that match how you sweat.
Precision Hydration founder Andy Blow has a degree in Sport and Exercise Science and was formerly the Team Sports Scientist for the Benetton and Renault F1 teams. A former elite-level triathlete, Andy has top-10 IRONMAN and IM 70.3 finishes and an Xterra World Age Group title to his name. He is now a leading figure in sports hydration.
