The UltraSwimming Podcast

Episode 4: Training with Charlotte Brynn, Joe Zemaitis & Sidney Russell

So what’s the best way to train for an ultraswim?

In this episode we welcome [Charlotte Brynn](https://ultraswimming.org/database/p/charlotte-brynn), [Joe Zemaitis](https://ultraswimming.org/database/p/joe-zemaitis) and [Sidney Russell](https://ultraswimming.org/database/p/sidney-russell), renowned ultraswimmers who are also experienced coaches to get their take on the perennial question of how to best prepare yourself for an endurance adventure as dynamic, unpredictable and complex as an ultraswim.

Our discussion covers four components of training for ultraswims:

* safe and efficient technique
* building endurance
* acclimatizing
* mental fortitude


While “everyone is different” (as we have grown increasingly fond of saying), we identify some key pieces of wisdom to share with you as you consider how to design and structure your training and preparation.

Music: 'Wanderlust' by [Scott Buckley](https://www.scottbuckley.com.au) \- released under CC-BY 4.0.

A few references from the episode:

* Charlotte Brynn, [swimwithbrynn.com](https://www.swimwithbrynn.com/)
* Sidney Russell, [swimopenwaters.com](http://swimopenwaters.com)
* Joe Zemaitis, [Swim Neptune](https://www.gomotionapp.com/team/assn/page/custom-page)
* Marathon Swimmers Forum thread, [Training Plans for Marathon Swims 10k and Up](https://ultraswimming.org/forum/discussion/1811/training-plans-for-marathon-swims-10k-and-up)
* [Training for a Marathon Swim](https://ultraswimming.org/news/2015/01/training-for-a-marathon-swim) by Evan Morrison
* Science of Ultra Podcast Episodes
- [Mileage Matters Most](https://www.scienceofultra.com/podcasts/136)
- [Training Intensity Distribution](https://www.scienceofultra.com/podcasts/148)
* Addie Bracy’s book, [Mental Training for Ultrarunning](https://www.thriftbooks.com/w/mental-training-for-ultrarunning_addie-j-bracy/27038138/#edition=57821861&idiq=45515125)

In this mini-episode, Jessica and Evan dive into a major new MSF project that’s just been launched:

- Our new website, ultraswimming.org which combines resources which were previously under three separate websites (marathonswimmers.org, longswims.com, and track.rs).
- Our new Member Portal app, in which MSF members can submit Documented Swims for ratification, set up GPS tracking pages, vote in the MSF Awards, and get online support for any issues or questions they may have.

This promises to create a more streamlined experience for MSF members, less manual labor for MSF administrators, and new opportunities for people to get involved in various aspects of the MSF project.

Some links to resources that were mentioned during the episode:

MSF Documented Swims program (2014 – present), Marathon Swimmers Federation

Repeatable Swim Routes, by Evan Morrison

MSF documentation of Sarah Thomas’ Lake Champlain swim

MSF documentation of Jessica Kieras’ Waldo Lake swim

Link to episode on Spotify: https://open.spotify.com/episode/1clFSao74XyWPBAaiNo7U3?si=6edf9581296a476b

Link to episode on Apple Podcasts: https://podcasts.apple.com/us/podcast/podcast-episode-1-karen-zemlin-lake-superior/id1845817729?i=1000731576760

Link to show on Spotify: https://open.spotify.com/show/4wovM2IebJ0mrfXN7vsmrF?si=5c1e3b71f6074ad3

Link to show on Apple Podcasts: https://podcasts.apple.com/us/podcast/the-ultraswimming-podcast/id1845817729

Podcast RSS feed: https://news.marathonswimmers.org/feed/mp3/

Recorded September 27, 2025.

In this episode we discuss how Karen Zemlin envisioned, planned and completed a new 22.9 km (14.2 mile) route on Lake Superior, from Isle Royale, Michigan to Pigeon Point, Minnesota in 6 hours and 12 minutes on August 13, 2025.

We talk about how this route differs from the already established east and west routes and what makes it an excellent addition to the options for ultraswims in the world’s largest lake.

Karen shared with us how the unique geography of the lake contributed to an upwelling as she swam toward shore, resulting in a twenty degree temperature drop down to 46°F (8°C). We learned how she coped with the cold and how her crew supported her in completing the swim safely.
Some links to resources that were mentioned during the episode:

- Official documentation from Karen Zemlin’s Lake Superior swim: https://marathonswimmers.org/swims/2025/zemlin-isle-royale
- Karen Zemlin's LongSwims Database profile: https://longswims.com/p/karen-zemlin
- Website for the Marathon Swimmers Federation (MSF): https://marathonswimmers.org
- Other MSF documented swims: https://marathonswimmers.org/swims/
- Jessica’s post on hypothermic swimmers losing consciousness on marathon swims: https://oregonlakebagging.wordpress.com/2021/01/09/swimming-to-confusion-stories-from-cold-water-swimmers/

A few links to projects mentioned in the episode:

Marathon Swimmers Federation (MSF): marathonswimmers.org

Long Swims Database profiles:
– Jessica Kieras
– Evan Morrison

MSF Documented Swims: https://marathonswimmers.org/swims/

MSF News Blog: https://news.marathonswimmers.org/

Link to episode on Apple Podcasts: https://podcasts.apple.com/us/podcast/episode-0-introductions/id1845817729?i=1000731656919

Link to episode on Spotify: https://open.spotify.com/episode/5sl7wwUeExB1wNE7NDm4V5

Link to show on Apple Podcasts: https://podcasts.apple.com/us/podcast/the-ultraswimming-podcast/id1845817729

Link to show on Spotify: https://open.spotify.com/show/4wovM2IebJ0mrfXN7vsmrF

Podcast RSS feed: https://news.marathonswimmers.org/feed/mp3/