Elite Endurance Athlete · Alberta, Canada

Cassandra
de Winter

Mother of three. Boston Marathon competitor. Course record holder. Proving that motherhood and elite athletics aren't mutually exclusive.

2:34
Marathon
1:12
Half Marathon
10:03
100km Ultra
Boston Marathon
Lost Soul Ultra finish
Mesa Half Marathon
Royal Victoria Marathon
Cassandra de Winter trail running in Alberta with the Lethbridge High Level Bridge in the background

Before anything else,
I'm a mom

Before anything else, I'm a mom to three young kids. My mornings begin early, balancing training with the familiar rhythm of little ones waking before the sun. In the midst of motherhood, I've found my way back to something that has always been part of who I am: movement, competition, and the drive to push my limits.

In 2025, after a few years focused on growing my family, I returned to sport through endurance racing. What started as a quiet comeback quickly turned into something much bigger. Running became a way to reconnect with myself, to rediscover strength, and to show my children what it looks like to chase something wholeheartedly.

My background in national-level rugby and strength sport gave me a foundation, but stepping into the endurance world has felt like starting fresh in the most humbling and exciting way. My journey is about balancing high-level training with motherhood, and inviting others—especially women and mothers—to believe that there is still space for their own ambitions.

The numbers

From 10K to 100K — every distance, every course record, built on early mornings and late-night feeds.

10 km
35:26
Half Marathon
1:12:54
Marathon
2:34:43
54 km Ultra
5:26:00
100 km Ultra
10:03:12

From comeback to course records

2026

Boston Marathon Pro Start
1st Canadian Female · 27th Overall Female
1st CAN Female
2:34:43
Moonlight Run 10K Course Record
1st Place Female · Female course record (unofficial)
1st Female
35:26
Mesa Half Marathon
4th Place Female
4th Female
1:12:54

2025

Lost Soul Ultra 100km Course Record
1st Overall (Male & Female) · 2200m elevation
1st Overall
10:03
Black Spur Ultra 54km Course Record
1st Place Female · 2230m elevation
1st Female
5:26:00
Royal Victoria Marathon
1st Place Female
1st Female
2:39:50
Taber Tuff Course Record
1st Place Female
1st Female
2:16:02
Coulee Cactus Crawl Course Record
1st Place Female
1st Female
2:47:43
Stampede Road Race
1st Place Female
1st Female
1:20
Calgary Marathon
2nd Place Female · 4 months postpartum
2nd Female
2:52:50

Built on a lifetime of sport

Rugby

University of Lethbridge · National Team

  • Canadian U20 Women's National Team (2011)
  • Canada West All-Star — Back Three
  • Conference-leading try scorer (2 consecutive seasons)
  • Key contributor to Canada West Championship team
  • Rugby Alberta — Lead scorer & captain (multiple seasons)

Powerlifting

10+ Years in Fitness Industry

  • Overall Female Champion — Drug Free Competition (2018)
  • Squat: 292 lbs
  • Bench Press: 156 lbs
  • Deadlift: 370 lbs
  • Certified Personal Trainer & Coach

What's next

May 2, 2026

Oldman Backyard Ultra

Last-person-standing format

May 25, 2026

Calgary Marathon

Marathon

June 6, 2026

Cactus Crawl

20 Miler

August 16, 2026

Edmonton Half Marathon

Half Marathon

September 11, 2026

Lost Soul Ultra

100 Miles

October 17–18, 2026

Toronto Waterfront Marathon

Marathon

Custom Bracelets

Beyond the trails and the finish lines, I make custom beaded bracelets by hand—colorful letter beads on elastic, each one spelling out a race mantra, a meaningful word, or a little reminder of what you're capable of.

Fun, bright, and made with the same DIY energy my kids bring to the craft table. Perfect for runners, little ones, or anyone who needs a bit of wearable motivation.

Inquire on Instagram
Letter beads and colorful bead kit for custom bracelets
Colorful handmade beaded bracelets
Kids showing off their DIY bead bracelets

@cassdewinter.runs

instagram.com/cassdewinter.runs