15 of the worst things to take trail running, according to an expert

Two trail runners pausing for water break in woodland
(Image credit: Getty Images)

If you are planning a trail run, whether it’s an hour or a multi-day adventure, there are some things to take that are a great idea – and some things that are most definitely a bad idea.  Here we offer a rundown of the 15 of the worst things to take trail running.

1. A heavy pack

Trail running packs come in a range of sizes, from those with a low volume for shorter runs to packs with a much larger volume that allow runners to take all they might need for several days on the trails. Whatever your plans, the aim is to (safely) minimise the weight of your pack. 

Running with a pack that is heavier than it needs to be (although you should read point 2) will slow you down – and, worse still, it will have the potential to cause rubs and sores on your shoulders, back and hips. 

There is a strong correlation between the joy of tail running and the lightness of your pack.

When packing your running rucksack, you should assess the conditions – warm, cold, wet or windy – and then choose your trail running kit accordingly. 

Could you ditch some of the water you are carrying, for example, and pick up water in fresh water streams as you run? Are there running food products that are lightweight but still offer plenty of calories?

Will it be warm and dry enough to pack a lightweight waterproof running jacket instead of a winter weight jacket or simply take a windproof jacket.

Go through your kit list and consider its weight, usefulness and also whether you will be safe if something goes wrong. Our tip is never to ditch the items that will keep you warm, dry and safe but to consider if there are lighter alternatives to clothing, food and drink.

female trail runner

Some of the worst things to take trail running can be what you wear (Image credit: Getty Images)

2. Too little kit

While a pack that is too heavy is definitely one of the worst things to take trail running, taking too little kit so that you run the risk of getting into danger is also a bad idea. 

There is a balance to be found between the amount of kit required for a trail running adventure and safety. 

Think about what would happen is you had an accident on the trails and needed to stay put while emergency help found you. It’s vital that you have enough clothing, layers, an emergency blanket or bag, a back up battery pack for longer runs and a mobile phone with you.

3. The wrong footwear

Road running shoes are one of the worst things you can take for a trail run. You want footwear that will offer sufficient grip on the terrain, whether it is park trails, forest tracks, hill paths or more mountainous ground. 

Trail running shoes with robust uppers and, possibly waterproofing, are a good idea for off-road running.

Wearing the wrong footwear, especially road running shoes, for a trail run will be frustrating at best and dangerous at worst. You want to enjoy good traction underfoot and feel your feet are well protected.

4. Brand new footwear 

Never set out on a long trail run in brand new footwear. It’s important that you know the trail running shoes will be comfortable. This usually means you should give the footwear a few shorter outings to check for comfort. 

Many runners will have made the mistake of believing that their brand new running shoes will be immediately well-fitting and comfortable but then they discover that their new shoes are one of the worst things to wear for running.

Runner suffering from foot pain sitting on ground

Wearing brand new shoes on a long trail run could be a painful mistake (Image credit: Getty Images)

5. The wrong bra

A bra for trail running should be comfortable supportive and made for your chosen sport. One of the worst things you can wear for trail running is an ill-fitting and unsupportive bra. So, it is important to choose a well-fitting sports bra.

The wrong bra will most likely lead to discomfort, rubs and sores and the long-term prospects of women who do not wear a supportive bra are stretched Cowper’s ligaments, which are not great news.

You might even improve your running performance wearing the right sports bra.

6. Shorts that chafe

Trail running can be a sweaty activity. It might be that you end up running in damp or wet conditions, too. This means that thigh chafing is a very likely result of wearing the wrong shorts or tights. 

Shorts or tights that chafe will be one of the worst tings to wear for trail running. 

Double layer shorts with a tighter fitting lycra under-short will help to keep thighs chafe free. Likewise, a pair of neat fitting running lycra shorts or running tights will also offer protection for sensitive skin. Also consider skorts for running.

To protect still further, try ant-chafing creams.

7. Socks that rub

You might be able to get away with a poor socks choice for a short trail run, but try running for any miles off-road in bad socks and you will quickly work out they are one of the worst things to wear for running, too. 

Make sure you choose good quality trail running socks – and check they are comfortable before you set off for a longer run. 

Sportswoman smelling stinky armpit in nature

Synthetic fibers tend to get smelly fast, which is bad news for multi-day adventures (Image credit: AntonioGuillem)

8. Clothes that whiff

You will be OK with synthetic running tops if they are fresh out the wash, but synthetic materials can quickly become the worst thing to wear for trail running if you're on a long adventure.

Instead, you are better to choose natural yarns, such as merino, because they keep you warm when it’s cold, cool when it’s hot and, most importantly, they don’t end up as whiffy as synthetics.

9. A worn waterproof jacket

You will be annoyed if you end up running in the rain in a waterproof jacket that is no longer waterproof. A worse case scenario is that you need to spend days on a longer trail running adventure wearing a jacket that is no longer fit for purpose. This latter situation could quickly become dangerous because you may end up cold, wet and, worse still, hypothermic. 

Take the time to re-waterproof your favourite jacket to, if you know it is actually past its best, buy a new waterproof running jacket.

10. A noisy jacket

Some people can cope with a jacket that rustles in the wind – but many can’t. Make sure your choice of trail running jacket for a longer adventure is noise-free otherwise it will drive you to distraction.

11. A watch with low battery

Make sure your GPS watch is sufficiently charged so that it keeps monitoring your run until you finish. It’s irritating to find that a watch has recorded only half of your running route because the battery has run out of charge. 

Runner drinking water from bottle on trail

It's important to carry enough food and hydration for your run, but taking more than you need will just weigh you down (Image credit: Getty Images)

12. Perishable food

If you are running in warm weather, the worst types of food to take with you are products that will go off, melt or curdle in the heat, such as chicken sandwiches, chocolate and milky drinks. 

Even in colder conditions, it’s worth thinking about how your chosen running foods, snacks and drinks will cope with being jostled about in a running packs for hours on end. 

13. Too much sweet stuff

Sweet foods will offer an instant hit of energy but it is usually short lived. In addition, many runners, especially long-distance runners, find that they can’t stomach too much sweet stuff and end up preferring savoury and salty foods.

Too much sugar can end up being one of the worst things to take trail running.

14. The wrong friend 

We all have our perfect trail running companion, whether they are chatty, silent, faster, slower, funny, serious or whatever. Choose you running friends wisely unless you want to end up realising half-way through that you have picked the worst friend possible. Imagine if this is a run of 100 miles or multiple days, too!

15. The wrong mindset

We all have days where we can't be bothered to go for a run, or we wake up feeling grumpy. A trail run can turn out to be the perfect solution for low mood but, equally, if you have the wrong mindset it will prove to be the worst thing to take with you on a trail run, especially if it's a long run.

Fiona Russell
Outdoor writer

Fiona Russell is a widely published adventure journalist and blogger, better known as Fiona Outdoors. She is based in Scotland and is an all-round outdoors enthusiast with favorite activities including trail running, mountain walking, mountain biking, road cycling, triathlon and skiing (both downhill and backcountry). Aside from her own adventures, Fiona's biggest aim is to inspire others to enjoy getting outside and exploring, especially through her writing. She is also rarely seen without a running skort! Find out more at Fiona Outdoors.