01013 How To Train For Swim Run Endurance Events Otillo 700x394

How to Train for a SwimRun Event Like the ÖtillÖ

BY Carrie McCusker

This Swedish-born event is gaining traction in other countries, including the U.S. Here’s how to properly prepare and train for your first SwimRun event.

One exciting newcomer to the endurance scene in the U.S. is a sport called SwimRun. The event originated in Sweden reportedly as a “drunken bet” in 2002, aptly named ÖtillÖ, a word that means “island-to-island” in Swedish.

In 2015 the first official ÖtillÖ came to the USA as the Casco Bay SwimRun in Portland, Maine. Participants, in teams of two, start on land and work their way across a bay or archipelago of islands by running the land portions and swimming between. The Maine event offered a mix of fog, chilly ocean temperatures, hot summer air and rocky coastlines.

As one of the race directors stressed at the race meeting, “this is NOT an IRONMAN,” and by that he went on to explain how much more unpredictable and uncontrolled the event would be, and what athletic requirements it would entail.

Because the sport is very new in the U.S., and in general, SwimRun gear is evolving. Companies are rapidly jumping aboard though, creating wetsuits that are good for swimming and running, and shoes that drain quickly and have excellent grip.

A large percentage of teams use pull buoys and paddles (to both conserve leg energy and increase swimming efficiency). Part of the excitement of the sport is the acceptance of almost any gear, but critical to choosing is that whatever a team starts with—it must also have at the finish.

Imagine running 10 miles with a large pair of fins in hand! Another important requirement of the event is the team element. Teams of two must stay within 10 meters of each other at all times. Most teams choose to use a tether that connects them at the proper distance in the water, and as was the case with my teams, throughout the bulk of the running as well.

Course distances vary. Some are “swim heavy,” thus favoring the strong swimmers, others are run dominant. A constant among them is the need to be able to successfully swim in open water, the ability to navigate water exits and entrances, and in most cases run a  mix of road and trail—all with gear in hand.

Training for this sport can involve three main phases presuming an athlete comes into the training with a general fitness base or a CTL of at least 20. The first, a general prep for six-to-eight weeks, followed by a race specific prep of four-to-six weeks and then finishing with a two-to-three week taper and peak for race day.

Race distance is the deciding factor for exact time spent in each period. Equipment choice can very quickly make or break a race, so selecting and testing gear thoroughly is essential.

The other very unique element of SwimRun is the way the two disciplines overlap. In triathlon or duathlon athletes make a clean transition from one sport to another—gear and all. SwimRun requires repetition of each and carrying equipment throughout. This post will address essentials for the general preparation, specific preparation and how to taper to peak on race day.

General Preparation

Like preparing for any long distance endurance event, athletes need a good base of aerobic fitness and strength. Allowing six-to-eight weeks to build up general fitness with the majority of time spent in HR Zones 1 and 2 in both swimming and running can lay a foundation.

For the run, build distance on road and trail, find rolling hills and get used to a variety of terrain types. Work in one day a week of shorter intervals, hill training or fartlek style running into HR Zones 3 through 5.

Swimming in a pool or outside are both successful strategies here, key elements include working in some longer reps, getting in the water three to four days a week, and using a pull buoy and paddles for some of the workouts.

Unique considerations for SwimRun are the transitions. Traditional multisport requires gaining some equilibrium going from horizontal on the swim to vertical for the transition run. However, during a SwimRun athletes are making this change many times and often on uneven and slippery surfaces.

To facilitate preparation, a good strength and agility program will help.True functional training that trains movement, not just muscles and focusing on the lateral plane in the gym can translate to improved ability on rocks and uneven surfaces.

Exercises like the slide board lateral lunge and plyometrics like skater hops in addition to a complete full body strength routine should be practiced and periodized throughout both general and specific prep.

Specific Preparation

The ideal specific prep incorporates more training that mimics race-like conditions with continued attention to general strength and agility and spans between four and six weeks.

Trail running, hiking and hill bounding are all great for run training. Key in this prep phase is incorporating race gear into the workouts. This means swimming with shoes, socks and the race suit, running with a pull buoy, and getting as many team efforts as possible—preferably while tethered together.

Slowly shift the workload more towards race-like efforts. Understand that although a long course SwimRun tends to be paced in zone 2 in general, due to the conditions, there will be efforts that exceed aerobic endurance and bridge into zone 3 and 4. Because of this, it is important to keep intensity in your training.

Practicing water entry and exits with full gear—as a team—will make race day more fluid. Some of the questions you want to answer and practice in this phase are:

  • Will you use a pull buoy, paddles, fins or a swim buoy?
  • How will you carry your gear while you’re running?
  • Will you take off your cap and goggles while you run, and if so, how will you carry them?
  • Do your goggles fog with all of the in-and-out of the water transitions?
  • Is your wetsuit comfortable enough to run in? Are you chafing?
  • Can you run successfully in your wet shoes and do the socks you chose work OK without chafing?

Practicing and working out the issues at the beginning of this phase will mean effective, quality training that leaves you feeling confident on race day.

Taper and Race Day Peak

I like to utilize an exponential taper, where the volume is reduced around 20 percent two to three weeks out from race date and gets progressively less in the week prior to the event. This allows adequate mental and physical recovery so race day can be a well paced, intelligent effort.

SwimRun requires decision making more than traditional multisport events, as navigation is also a factor. Race week should lean heavily toward proper nutrition, hydration, and SLEEP! Focus on details daily: foam rolling, basic mobility and practice visualization and positive self talk.

Know that you’ve done the work and you’re ready. The night before the event, mentally walk through the race and consider what decisions you might make in different scenarios. If you haven’t seen the actual course, be sure to study maps of the area and be clear on exit and entry points as well as any tricky trail sections. If anything is confusing, ask at the race meeting.

Here is an athlete’s speed and heart rate graph from the Casco Bay SwimRun in 2016. Most obvious is the change in HR from swim to run, and a demonstration of the level of effort for over four hours of racing.

During the running portions, their heart rate pushed to threshold and above, in particular the athlete was affected by warm temperatures and a black wetsuit that trapped the heat, plus she was wearing a swim cap that also minimized cooling.

The biggest takeaway from this data is the need to consider proper pacing, fueling and hydrating during the event, and looking for ways to regulate core temperature, both in and out of the water.


SwimRun is a fun, adventurous sport that requires mental acuity, physical agility and endurance. Prepare properly, and your first race probably won’t be your last!

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About Carrie McCusker

Carrie McCusker is a level 2 TrainingPeaks coach and a lifelong athlete who enjoys bringing individual attention to every level of athlete. You can find her on Strava and Instagram or check out her coach profile at TrainingPeaks.

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