Ironman Run Training – Trail Running – Why Every Ironman Should be Running Off-Road

Running is potentially by far the most damaging of the 3 disciplines to Ironman Athletes. The constant impact on leg muscles and joints can easily ironman run training trail runninglead to overuse injuries of the muscles, joints and Tendons. Training to run a marathon involves large amounts of running. While Ironman Run Training the body is already stressed from the swim and cycle training making injury even more likely. Anything you can do to reduce this risk is a positive.

Trail running is one way to reduce stress on the lower legs, as I will detail below so its the perfect excuse to get out and get muddy!

Injury Reduction


When running the most damage comes from the impact of the body landing on each foot stroke. This has a cumulative effect over time and leads to fatigue and soreness in the muscles. It also strains the tendons and joints. Over time this can lead to overuse injuries. By running off-road a large proportion of your foot falls will be on soft surfaces. Mud, Grass Gravel etc… instead of rock solid asphalt. Imagine head-butting a concrete slab vs. a concrete slab with thick cushions on it?


Off-road terrain is also very varied. Uphill, downhill, flat undulation etc… this variation has the benefit of changing which areas of your  muscles and tendons are being more heavily stressed. This means the cumulative load is spread out more evenly throughout your body. This means any one point of weakness is less likely to fail.

Strength Building – Toughness

Variation also applies to the surface. You are very likely to be running on varied uneven terrain. This will unconsciously activate a whole multitude of Supporting muscles and tendons that are never usually used in road running. This helps generally strengthen and toughen your legs which in turn makes you a stronger tougher runner and also helps resist injury in the long term.

Its also normally a lot harder. That Soft bouncy stuff provides added resistance and the push off is often weakened by a yielding surface. Meaning each mile is tougher. Not to mention the added undulations also add to the fatigue. But Ironman training is not meant to be easy. These Tougher miles will have an added training benefit that will show come race day. Its not coincidence that Fell/Trail runners are considered the “toughest” Runners.

Fun – Be Inspired by Naturewilderness trail running

Its also REALLY great fun. Pounding up and down dreary roads can be a very mundane activity. Taking that running out into the natural world is a great way to relieve that boredom and also help relieve the stress of everyday life as well. There really is nothing better than getting back to nature, running though forests, up hills, past lakes and rivers. Its a true tonic for the soul.

Negatives – Cleaning Bills and Grumpy Partners

The negatives are really pretty sparse. I guess the only down sides are the added cleaning of muddy kit. and also the possible aggravation of traipsing muddy clothes and shoes into your home which may upset your significant other…unless you can talk them into coming with you?

Depending on the type of trail running some extra kit can be required but this is main due to minimising the inherent dangers of being in a remote place.


Trail running is really anything where the surface is not tarmac/asphalt. So any time you leave the black stuff behind is counting toward your Trail running badges.

Trail / Felltrail running mountain

Fell running or Trail running is the pure Off-road pursuit. This is leaving the Paved world long behind and heading deep into the hills, Mountains or country. I am very lucky to live in an area full of opportunity to get out into the hills. Not all of us are but most can be with a short drive. The Problem with this type of running is you are heading off into the real wilderness and a level of self sufficiency is needed. You need to know where you are going and what the weather may do, and how to find your way back. But the pay offs are huge. There is nothing more inspiring than running freely though the wilderness. The speeds you run at mean large distances can be covered easily. Long trails that take almost a day to hike can be knocked off in a couple of hours.

Parks / Maintained Trialscity sun hot

Not all Trail and Off-road running is done on high mountains and remote Forests. Almost everyone has access to a park no matter where they live. Parks afford everyone the opportunity to get off-road. It might not be quite as inspiring as scaling a mountain top. But you can still reap all the benefits. Park running also doesn’t expose you to the risk of remote trail running so you can pretty much ignore the kit list below and just think about some gripper shoes.


Fell Racing or Trail Racing is a very popular past time. And its great training especially in the off season. Hard racing on harsh terrain can be risky so its best left to the off season to not jeopardise a big expensive A – race. Nothing really teaches you to suffer like a hard fell race. Its well documented the Brownlee Brothers Cut their teeth Fell running. But you don’t need to be a super hard Yorkshire Olympian to give it a go. Races are very friendly and the field is very diverse. They can also be Ludicrously cheap (£4) to enter. http://www.fellrunner.org.uk/  List all the UK Fell races and there are hundreds of organised Trail races the world over.

Mud Runs

Another Option is Mud Running or obstacle. These Events, such as ToughMudder, are rising rapidly in popularity. They are great fun. But I struggle to recommend them for Ironman training. For one I feel they are pretty expensive for what they are (£50-100) and the risk of injury is pretty high. An Athlete of mine was roped into one through work, and ended up scratching his cornea in a freak accident. He was electrocuted in the head (electrocution is part of the fun!)  Fell face first into the mud, and woke up rubbing his eyes. The mud in his eye actually scratched his cornea leaving him partially blind. Thankfully the eye healed and he is fine now but it was a couple of months out of action. Of course that sequence of events is unlikely but there are a thousand opportunities to twist an ankle, fall over, or generally injure your self. Its just not worth the risk. If you must save them for the off season.

Its not that these are bad events (if Pricey) Its just not very suited to Ironman Training. You are training for one of the hardest endurance events on the planet. Is a 10k mud run really worthy of your time/effort and money ?

Kit – Comfort

Unfortunately running off-road can require a bit of extra kit. Obviously some of the below kit is overkill as you are unlikely to get in trouble navigatingTrail shoes your local park. But heading out into the wilds its surprising how quickly the weather and fortunes can turn!


Shoes – Trail shoes are essential when ever the trails are poor quality. And I don’t mean “bad” Just very uneven, rutted, muddy, slippery or rocky. Trail Shoes offer much gripper soles. This is essential if you want to make ground and stay upright on slippery or muddy terrain. They are also very supportive shoes and this added stability helps on uneven terrain, keeping your ankles straight and allowing you to ride bumps holes and ruts.

hydration packhydration waist packhydration vest





Nutrition System – Heading out to places where civilisation no longer exists means any thing you may need needs to be carried along. I’ve been forced into situations where I’ve had to eat snow or drink river water because I didn’t adequately prepare I’ve even taken to eating berries on the odd occasion. A simple Hydration system is all that needed. The main types are either a camelback type bladder system where the fluid is contained in a plastic bladder and drunk though a long straw. A Waist pack With conventional water bottles strapped to it, or a vest type system again with bottles. The Bladders are most versitle but when full can bounce a bit and can rub or chaff. Wait packs are great but limitd in size. The Vests are best for very long distance (Ultra running) As they distribute the weight evenly and this minimises the risk of bounce induced chaffing.

A Nutrition System also offers somewhere to store food and other items to take with you. This is where you would store the rest of your kit.

compass map

Map, Compass – When heading away from civilization its also a pretty sensible idea to know where you are going! Locally I have a very good knowledge of where I am but still bad weather can roll in fast leaving me pretty lost. A basic compass and a map of the local area really can be the difference of you finding your way back … or NOT. Its amazing how fast fog can roll in and how disorientating it can be. Just remember a map and Compass are completely useless if you don’t know how to use them?

Warmth – Even Running in the snow, high up in the hills on very cold days its incredible how little clothing you need! Your Internal Heating engine is pumping out a ton of heat while powering you up the hills. But have you ever thought what would happen if that stopped? Say you twisted and ankle, and all you could now muster was a hobble. You are now going to get VERY cold VERY quickly! The minimum you need in this situation is lightweight wind/rain proofs and a space blanket as a backup. Its the wind that chills you fastest so a top and trousers that block that out give you a lot longer until the cold becomes dangerous. A space blanket is so light and so effective its just common sense to carry one. you can source one from EBay for almost nothing!

Phone –  Ok reception maybe patchy where you are headed but really, we all have these marvels of technology and it might just work when you need it most so take it along. It certainly won’t help back in your glove box in the trailhead car park.

Whistle – As great as modern Tech is it can and does fail so we need the old fashioned back ups. In heavy fog you can be 10 metres from someone and never know. So making noise is a great way to bridge that gap. Yes you can just bellow. But that becomes tiresome after an hour or so. A whistle takes little effort to make noise and the shrill call carries well on the wind. They are also very light and very cheap!



All Kitted with the above you are good to go but its still necessary to take a few precautions. If you can, don’t head out alone. And in any case let someone know you are going, where and roughly how long you will be. That way in the unlikely event you don’t return help can be sent.

Always know your planned route. Plan landmarks and waypoints to know you are on track and try and plan contingency routes. Alternatives to get you back to civilisation. Its much easier to find yourself on a map if you have a good idea where you were when you become lost.

Know the weather and if its really poor consider giving the route a revision. Heading off up a high mountain when a blizzard is forecast is not the smartest move. Trial running is all about the outdoors and inclement weather is a part of that. But when things are extreme its just better to stay a bit closer to civilization and safety. Get it wrong and you are risking not only your life but the lives of the rescue teams who WILL come to look for you.


As I have said before the Safety aspect of this post is only intended if you plan on heading out and away from civilization. A off-road pootle around your local park does not require the same precaution. Even so these moderate precautions should not put you off. There is a massive Amazing natural open space out there and exploring it is not only great for training its also great for the soul. With a winter of Turbo training and pool swimming to grind trough what better way to find some joy in your training than heading for the hills or breaking a trail through the forest snow.

Get your Trail shoes on and get out there!

I’d love to hear from anyone who uses off-road running as part of their training or just runs off-road at all. Where do you run? Are you on the doorstep of somewhere great like me (High Peak, UK) or do you need to travel for your out door kicks? Feel free to comment or ask any questions below.

Stephen James


  1. Hi Stephen, I have never considered training for any ironman competitions, but I do like to get out into nature and run around in rural areas. There is nothing better than getting runners high and absorb all of the nature around you. I feel unstoppable, like I can just run forever. I also love to go running whenever I travel, and I love to just sight see, and watch everything pass me by as I run.

    I gotta say though, the guys who go through with this kind of stuff during the winter. I can’t imagine it, I can’t take the cold blizzard days, I usually go work out in a facility when it comes to that.

    • Hi Jacob, I do understand the temptation to hide away when the going is tough. I am a fair weather cyclist as I can stand Cycling outside when its bad. But running is different for me. The runners high and feeling of one with nature is only heightened by inclement weather. Breaking a fresh trail through the snow is one of life great joys.
      The challenges created by poor weather only make the resulting highs higher. Of course getting out the door can be the toughest challenge. But once out immersed in nature its a hard feeling to beat!

      Thanks for reading Jacob

  2. Ironman run training is truly amazing. I do intermittent fasting in this month. Do you think I should go before breaking the fast or after?

    • Early on during intermittent fasting you are going to need to avoid a lot of exercise during the fasted periods. Your body will not be able to provide the Blood sugar you need and you could end up hypoglycaemic (low Blood Sugar). So definitely only go after eating. This is especially true of running into nature as you need to be close to some form of nutrition should your blood sugars drop.

      As you go on with your intermittent fasting though the body should get better at metabolising fat for fuel and then its pretty irrelevant when you run. All I would say is any hard runs you will need to eat protein after so your body can rebuild so maybe running near the end of a fast period so you can eat afterwards would be a good plan.

      But any fasted running should be experimental. don’t venture too far from home/shops/civilisation in case you run low on blood sugar. In which case eating is the only way to get you home safe.

      Thanks for reading

  3. This is a great article on the running aspect of Ironman! I prefer to run on treadmills. I usually put the treadmill on an incline of about 2.5%, in order to simulate running on an outdoor track. Do you think running on a treadmill is a good way to prepare for the running portion of an Ironman competition? How many miles a day do you think I would need to run in order to train for Ironman? Also, does training for Ironman lead to any sort of muscle loss?

    • Personally I wouldn’t use a treadmill for Ironman training. But that is mainly from a mental aspect. I just wouldn’t want to spend hours grinding away on a treadmill. Getting out into the wild helps relieve some of the tedium of iron distance training. There is no physiological reason why not though. Its important to get a few long runs outdoors before the race as there are subtle differences between the two.

      You can actually get away with a lot less running distance than most people expect. I only do two weekly run sessions. A short run of 4-8 miles and a long run of 8-20 miles. With the distances building as you get closer. It can be mentally reassuring to do a practice marathon before but this is not necessary.

      Training in itself would not lead to muscle loss. But a high calorie deficit which is probable due to the high volumes of training could lead to muscle loss, along with fat loss. Of course its good muscle loss. leading to a tight toned body, but it might not be the perfect beach body some people desire. More an athletes physique.

  4. Hi Stephen,
    This really opened my eyes and it did so right from the start. The idea that running off-road would have so many benefits over the road surprised me, but makes perfect sense. I’d have thought there would be far more trip hazards, but the softness and variety and stimulation of an off-road environment vs the pounding of concrete or asphalt makes complete sense.
    I’ve been skipping rope over the last year, but found out the hard way the toll the repetitive pounding can take. I got awful shin splints in my left leg that took months to heal. I’m much more careful and selective now.
    Keep up your great work!

    • Hi Kevin

      Thanks for reading. There are of course more trip hazards but with care, it’s no more or less risky than road running. Part of this awareness is also what helps you become a better runner as your body and mind work in harmony to overcome the obstacles. This Synergy also helps lessen the pounding. you are more careful how and where you PLACE your feet. rather than the monotonous thud thud thud of road running.

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