We all know that fell running in hot weather is hard work; we heat up, we sweat and need to rehydrate. But what about in winter?
It’s just as important to stay properly hydrated whatever the weather but in winter when it’s cold we don’t have the same psychological and physiological triggers telling us to drink. In cold, dry weather sweat evaporates quickly and so we might not notice how much we are sweating and because we don’t feel hot there is less urge to drink. Some scientific studies have also shown that in cold weather as the body shuts the blood supply to its periphery, the urge to drink is reduced. There’s also a phenomena known as cold diuresis where the body increases the production of urine as it gets cold which in turn can increase the risk of dehydration.
In cold, dry conditions the air that is breathed in gets warmed and humidified during respiration so every breath out robs the body of a tiny bit of water. This all adds up on long runs, especially when you’re breathing hard.
It doesn’t need to be hot to make you sweat; if you’ve ever run in the rain wearing a waterproof jacket and complained that it’s leaking, that’s actually sweat that hasn’t been able to evaporate. Likewise when you take your backpack off you’ve probably noticed a “sweaty back” even on a cold, winter day. Again this is a sign of how much fluid we lose even in lower temperatures. Extreme dehydration is dangerous but even in the early stages it has a detrimental effect on performance, causing you to slow down and increasing the feeling of fatigue.
So it is apparent that drinking during your longer winter runs is just as important as it is in summer. I like to use Nuun electrolyte replacement tablets for both summer and winter hydration. The tablets dissolve quickly and are easy to break in two to fit into narrower necked hydration bladders. They come in a range of flavours that aren’t too overpowering and unlike high sugar carbohydrate drinks aren’t sickly sweet. The added electrolytes are important, especially for very long runs and are another reason why I prefer them to carbohydrate only drinks.
There are several ways to carry your drink, each has advantages and disadvantages and different people have different preferences. I like to use a bladder in a backpack so that I can keep sipping with minimal disruption and because there is no air in the bladder the contents don’t slosh around as it empties.
However the downside of this is if you plan to refill the bladder during your run (as in an Ultra distance event) it can be a tricky and time consuming process, particularly with a narrow necked bladder. In this case a wide necked plastic bottle might be better as it will be much easier to access and quicker to refill. Some rucksacks are designed to carry bottles on the front shoulder straps which are easy to use, but for me, annoying when they start to slosh around when half full. I also find them a bit heavy and uncomfortable when full.
Alternatively you could use a bumbag designed to hold a water bottle. You need to either reach behind you or more realistically spin the bag round to remove and replace the water bottle. I don’t really like this method if I’m likely to be running fast as I find that it makes the bumbag more prone to bouncing up and down.
For some shorter runs or races when I only want to take a small amount of drink I will reuse a baby food sachet, cleaned and then filled with my Nuun drink. Carried in my bumbag this gives a few mouthfuls of liquid, just enough to get me round.
You could even run carrying a water bottle in your hand. There are bottles designed specifically for this but for me it is a big No No for a number of reasons: It disrupts your running style, it is uncomfortable, it hinders you from using your hands to do anything else (e.g. check your map, open a gel etc). I think that if your run is short enough that carrying a bottle won’t annoy you then it is short enough not to need a drink. If it’s long enough that you will need a drink then find a more efficient way of carrying it and let your hands swing freely in an efficient running style!
I always ensure that I am fully hydrated before a long run or race in order to delay the onset of dehydration and then sip frequently during the run. I find that little and often is better than glugging loads down at once.
So whatever your chosen method of carrying a drink, remember that rehydrating on your longer runs is important even in winter. Using electrolyte replacement tablets such as Nuun in your drink is an effective way of preventing dehydration and the associated decrease in performance.
Bearing that in mind you can get out and enjoy your trail and fell running this winter – happy hydrated running!