Swimrun is an exciting sport and a fantastic experience recommended for any triathlete. But how do you best train for one - whether you want to complete or compete? Andy Blow, former elite triathlete and founder of Precision Hydration joins us to discuss effective Swimrun training.

• Fitness prerequisites for signing up for a Swimrun. 
• How to train for completing a Swimrun.
• How to train for being competitive in a Swimrun.
• How different is the swim and run training for Swimrun compared to swim and run training in triathlon?
• Swimrun gear advice and recommendations. 
• Swimrun nutrition and hydration advice and recommendations. 

4:01 - 

• If you can do a triathlon you can do a Swimrun, if you pick the right race.
• In some of the races with a big open water component or a lot of swimming compared to running, don't underestimate how good your swimming needs to be.
  • The swimming is not like a triathlon swim, it's much more "in the wild".
• You need a good level of confidence in your swimming but it doesn't mean it's not accessible to most triathlon swimmers.
• With the Ötillö World Series races, most have a sprint race on the day before or after the main race.
  • These are more targeted at getting people into Swimrun.
  • They call them sprints but they still often take 2-3+ hours to complete.
  • They're often a little more sheltered and are a good example of a more accessible event.
• I did a long distance Swimrun on the Isles of Scilly last year. The winners took just over 4 or just over 5 hours to complete it.
  • It's around 30km in total distance, with 20-22km of running and 8-9 of swimming.
  • Roughly two thirds running, one third swimming.
• The shorter races tend to have a similar ratio but the total distance is shorter, more like 15km total.
• Each race varies because of the terrain and type of environment is different.
• The events in the Scilly Isles are different because they didn't do the big 2km open water openers.
  • The swims are in coves or along the shore line so they're more sheltered and accessible.

8:14 -

• If you just want to complete it, and if it's not your main focus race if you're a triathlete, the vast majority of the training for it you're already doing as part of your triathlon training.
• As long as you're swim fit to your level, and run fit to be able to cope with the hours and kilometres that the race is held over, you've got all the basics in place.
• It's worth looking at some specific practice:
  • Try swimming with your shoes on.
  • Adapting to use things like a pull buoy and paddles in the swim.
  • Figure out how these things will affect you.
• If you're a swimmer with a good leg kick, this can hamper you in a Swimrun.
  • If you swim with your shoes on and with a pull buoy, your leg kick is less relevant.
  • I found that the stronger leg kick swimmers tended to struggle a little.
• Find out how easy you find swimming in the accessories you'll need for race day.
• If you get the opportunity, train alongside the person you're competing with.
  • You can figure out who is faster in each discipline and whether you're going to tether together etc.
• The details are important, but for the fundamental aerobic endurance and performance you can probably rely on your swim and run fitness from triathlon training.
• I did a race when I'd never trained with my partner as it was a last minute decision.
  • It was the Casco Bay USA Swimrun. I did it with Nate Larley. His brother Todd runs a company called Coast Endurance.
  • Todd and Nate were going to race together and had done all their training.
  • A few weeks before, while they were on the course training Todd kicked a rock and broke his toe.
  • I jumped in to race with Nate.
  • It was a cool experience, we met two days before, did a swim a run together and then raced.
  • It worked brilliantly, we got on really well together.
  • We agreed to start slowly and try and move through the field. He was a great partner and knew the area.
  • All of that said, I would definitely recommend training regularly with your partner as it gives you a big advantage.
• The first time I did the Ötillö World Championships in Sweden I only did 6 proper Swimrun training sessions.
  • You do a lot of swimming and a lot of running still.
  • But unless you live somewhere where you have place to can easily jump in and out of open water and run alongside it, logistically it's hard to do this training.
  • As long as you can do it a handful of times, that's probably good enough.

12:43 - 

• The guys and girls at the top are basically doing Swimrun-specific training, they're not triathletes (anymore).
  • If they're riding their bikes at all, it takes its place way down in the training hierarchy.
  • They're probably doing a lot of very specific swim training in open water with full kit and shoes.
  • They're also probably doing a lot of trail running that's very specific to the nature of the courses.
    • Some people are quite shocked when they turn up somewhere like Stockholm for the race in September and find some of the running isn't really running, it's climbing over boulders and scrabbling through trees.
    • If you haven't got your mind and body prepared for that you'll find it quite tough.
• If you want to be competitive now in Swimrun the training specificity on the type of environment that the course offers is very important.
• The ratio of swim to run training depends on personal strengths and weaknesses.
  • If you are a strong swimmer already, but running is a weakness, you will tilt the training in favour of running and vice versa.
  • If you're fairly equal on swim and run, and fairly equal with your partner, you'll probably do a 50/50 split in the week.
    • Obviously the mileage in running with be higher, but it will be a reasonably equal proportion of time.
• This split helps as running is the sport people are most likely to get injured in, so if you can compliment it with days where you only swim it's a good thing.
  • I've found for me that although I'm a stronger runner marginally, I inevitably end up doing more swimming because of injuries.
  • Swimming is a safer way to get fit.
• A friend of mine, Paul Newsome (founder of Swim Smooth), and I are racing together in Stockholm this year which is my main goal for the year.
  • We used to train together when we were 19-21 and then were out of contact for a few years.
  • We're both 40 this year so we've decided to sign up and do the race together.
  • Instead of it being a competitive goal for the year, my goal is to not let Paul down and to keep up with him basically!
• I'm also doing the race in the Isles of Scilly in June as a build up race.

16:24 - 

• I'll be 16 weeks away from my A-race at the end of this month.
• Up until now I've just been gradually increasing my swimming and running mileage.
• I tend to work well these days off a four week cycle: 3 weeks increasing, 1 week easier.
  • This helps me not to burnout and not get injured as much.
• The length of the race I'm doing in Sweden is more tilted towards volume rather than intensity.
  • It's 9km swimming and 60km running.
  • I'm therefore aiming to accumulate more and more running and swimming mileage through the weeks.
  • How fast I can go is a secondary goal to be robust enough to survive the 8/9/10 hours the race is going to take.
• I remember being surprised at how broken I was after doing this race last year.
  • I think that was the nature of running 60km on relatively low run mileage.
• My training these days is such that 9-10 hours a week is a solid week for me.
  • I've got a busy job and two small children!
  • I aim to train every day but inevitably travel gets in the way and I end up training 6 days a week.
• I usually swim 3 mornings a week.
  • It's currently exclusively in the pool but I'll soon be moving one to the open water.
  • These sessions are between 2.5-3.5km, and will eventually be pushed to 4.5km.
• I live about 2-3 miles from my office, which I can extend to 4-5 miles so I try to run in and out of work 2-3 times a week.
  • I also do a longer run at the weekend.
  • Starting with 8-9km and eventually building to 30-40km closer to the race.
  • I will also add in one speed run session each week.
    • This will probably be 800m-1km repetitions.
    • I'll do that 3 out of 4 weeks.
• Where I live there are a lot of coastal trails, so 50% of my runs is on soft underfoot/rocks/trails etc.
• When I do my long runs I make sure it's predominantly trail running.
  • This is helpful for the strength in your ankles and climbing and scrambling over rocks.

20:46 - 

• For me I use paddles a lot more in training because there's a strong possibility that I'd use them in a race.
  • If it's very rough and windy I wouldn't use them in the race.
  • However Paul believes they can be advantageous in flat, smooth conditions if you've done the mileage to be strong enough to use them.
  • When there's a high ratio of running to swimming they can be more of a hindrance though.
  • Paddles can help build open water swimming strength anyway.
• There is more of a focus on specific sessions in the open water with shoes, a pull buoy and a Swimrun wetsuit.
• The sessions I do in the pool are very similar to what I did when I was training for Ironman.
• Emphasis on race pace work, 100/200/400m repetitions with short recoveries.
• Very occasionally high end speed work to stay sharp and efficient.

22:27 - 

• One thing which is strange but helpful is going for short runs in the wetsuit.
• You need to make sure you're comfortable running in the wetsuit you've chosen.
• You can also check you're able to carry the gels and equipment you'll need for the race.
• The run sessions are a bit like doing any kind of trail ultra marathon training.
• However not neglecting that you will likely encounter very rugged underfoot conditions during the race.
• Even if it's only getting in and out of the water.
• Don't expect it to be a smooth beach climbing in and out of the water.
• Getting used to running on the rough stuff is really important.

23:39 - 

• Equipment is a big topic in Swimrun and it's still evolving because people haven't figured out the most efficient ways to do everything yet.
• As a starting point, look at every piece of equipment and be sensible, but also be as minimalist as possible.
• What's the least you can carry, what's the lightest you can go?
• Some people do the race with a Camelback, nutrition and first aid kits.
  • For me, the drag of having to swim with the backpack for up to 10km probably isn't worth it.
• Shoes need to be lightweight, quick draining with very good grip.
  • I tend to lean towards the Inov8 shoes because they have flexible rubber soles and good grips on the rocks.
  • Basically anything you feel comfortable running multi-terrain on.
  • If you're not light on your feet it's worth looking at something with toe protection.
    • It's very easy to kick rocks when you're coming in and out of the water.
    • It's easy to break or bruise a toe if you don't have toe protection.
  • If it's really cold I have used some very thin (0.5mm) neoprene socks inside the shoes, which help a little with buoyancy and keep your feet warm.
    • If you think you might need those on race day, make sure you do lots of run practice in them to make sure they don't cause blisters.
  • Otherwise, regular socks or no socks.
• I've used neoprene calf guards in most of the races I've done if I've not worn a full wetsuit.
  • They help with the buoyancy of the lower leg and help keep you warm.
• Most people will opt to use a pull buoy.
  • This is sensible because it helps keep your feet and legs higher in the water and keeps your hips up.
  • There's plenty of videos online to show you how to drill it and put some elastic laces through to attach it to your leg.
    • You can then rotate it in and out when you're running and swimming.
• If you're going to tether to your partner you may need a thin belt with a loop to attach the tether to.
  • This should be thin and lightweight and sit fairly close.
  • You can make something yourself or get something that Velcros on.
• In terms of the wetsuit, in the first Swimrun races I did I wore a triathlon wetsuit that I'd cut up (legs) with a zipper down the back.
  • I think this was a big disadvantage.
  • If you can afford to splash out on a Swimrun wetsuit and have the zip at the front, it's great to be able to unzip it for the longer runs.
  • You can cool down more effectively and get nutrition from inside your suit.
• Whether you go for paddles or not is an important decision you need to make early on.
  • If you're going to use them you need to put training mileage in with them.
  • I'm currently working with a set of small and a set of medium paddles and trying to see if I have a preference.
    • It seems to me at the moment that on a calm day I'd use the larger ones.
    • On a rougher day I'd use the smaller ones.
    • On a very rough day I wouldn't use paddles.
• You may want a neoprene hat or ear warmer to go under your race hat if the water is very cold.
• A good set of goggles that have lenses that are the appropriate colour/appropriate sun protection depending on the race.
• Mikael mentioned a few extras:
  • Thermal wear under the suit which helps to stay warm when it's really cold.
  • With the wetsuit itself, it's much better to run in a good Swimrun suit as they're more flexible.
• Relevant especially to the Ötillö races:
  • Some of them, for ecological reasons don't have cups at the aid stations, so you need a small bottle to fill up and drink from.
  • You can get silicone bag drink bottles that collapse down.
  • You could carry one in your suit and then drink on the go, before putting it back in your suit for the swim.

31:31 - 

• I've only raced Ötillö and the Swimrun USA races which have both got really excellent energy and aid stations on the courses.
• If you're racing in a race where you think there are enough aid stations to see you through the course, I would tend to carry close to no nutrition and hydration.
• I usually carry 3-4 energy gels because I may want to supplement what I'd get on the course for the longer stretches.
  • They also work as a back up if I feel I'm too low on calories.
• Out of the 4/5 races that I've done, I've probably only taken 1-2 of those gels. I mainly rely on the aid stations.
• This means you need to give yourself extra time at aid stations to make sure you're getting adequate calories and fuelling and hydration.
  • It removes the need to carry extra stuff with you.
• This method takes confidence in your ability.
  • I have been racing relatively close to the front of races, so moving a bit faster means there's less time between aid stations.
  • If it's taking you longer, you may want to carry more to supplement.
• The longest race I did was just over 9 hours.
  • I would typically aim for 60-70g carbohydrate an hour, in line with sports nutrition recommendations.
  • At the race I found that, without being silly, I ate as much as I could at the aid stations.
    • I was eating 3-4 items at each aid station.
    • An item being: an enegy gel, half an energy bar, a piece of cake, jelly sweets, fruit etc.
  • I took the view that a little more was better than a little less.
  • I would wash that down with Precision Hydration electrolytes and some water.
    • Precision Hydration provides the drinks for the Ötillö races which works well for me.
  • Within reason, I would be drinking as much as I felt comfortable to tolerate at each aid station.
    • Between 2-4 cups of fluid at each one, knowing that it'll be a while until the next one.
  • It was rare that the aid stations were significantly more than one hour apart.
    • On the long run I did get very thirsty.
• You can burn through calories more quickly during the cold.
• This year I plan to fill up a 16 ounce silicone bottle to take for the longest run stretch.
• The sports nutrition recommendations suggest taking in the energy ​quite frequently.
  • People with sensitive stomachs will need to practise a strategy like Andy's (taking on a lot in one go) in training to teach their bodies to tolerate it.
• I think you can train your body to manage increased calorie intake/fluid intake.
  • Where I like in Bournemouth there's a café about 10km from my house by the sea.
  • To Swimrun there it can take me about an hour and a half to get there.
  • I do that as training with no fluid or food, stop at the café for food and drink and then do the same return.
  • It's not nice running and swimming with the full stomach feeling but you get used to it with training.
  • It's important to practice this.

38:55 - 

• I think, because the pain memories have faded, the big Ötillö World Championships in Sweden.
  • It's such an epic event, it's so well organised.
  • The scenary is unbelieve.
  • It's rugged and it tears you to shreds, so it's the ultimate experience.
• The Scilly Isles race is beautiful too.
  • Last year the weather was perfect, it was like being in the Mediterranean.
• The one in Casco Bay in Maine is equally good.
• One of the great things about this sport is the location - I've not heard of a race in a bad location.
  • They've all got something to offer.
• I've not been there, but the one in Hvar in Croatia looks phenomenal.
• For me, in terms of the all round package the big one in Sweden is the one to aim for.
• There's a new one in the San Juan Islands that is top of my wish list.
  • I think it's close to the World Champs in the calendar this year though.
• Part of me also wants to do the Engadin one in Switzerland.
  • I'm a little bit afraid of the cold water there!
  • I think it's single digits in Celcius, and at altitude as well.
  • It doesn't put me off but it changes the preparation.
• Åland Swimrun in Finland is highly recommended by Mikael
  • Water temperature is around 13 degrees.
  • Similar to the Stockholm race but the running is more rugged and remote.

Links and resources mentioned

• Hydration, sodium and cramping with Andy Blow | EP#49
• How to train for a Swimrun | EP#57
• Åland Swimrun with Simon Brierley and Mikael Eriksson | EP#63
• Precision Hydration's Free online sweat test
• Ötillö Swimrun World Series website
• Åland Swimrun

Connect with Andy Blow

• On Precision Hydration's website
• On Twitter: @andybl0w

Connect with host Mikael Eriksson

Hi! I'm your host Mikael,

I am a full-time triathlon coach and an ambitious age-group triathlete. My goal is podium at the Finnish national championships within the next few years.

I first started the website Scientific Triathlon in autumn 2015 as a passion project to share my learnings with a larger triathlon audience. Later on, in early 2017 I started the podcast That Triathlon Show. 

I sincerely want you to contact me to

• Send me feedback
• Give constructive critic​ism 
• Request topics and guests for the podcast
• Send me your triathlon-related questions 
• Tell me that you've rated and reviewed That Triathlon Show so I can give you a shout-out on the show and tell you how much it means to me!