370 Lakeside Triathlon
370 Lakeside Triathlon is a triathlon, aquabike, duathlon, running, and swimrun race on August 23, 2026 in Saint Peters, MO, with entry fees from $32.50 to $290.
- Date
- August 23, 2026 (31 days to go)
- Price
- $32.50–$290
- Sports
- TriathlonAquabikeDuathlonRunningSwimRun
From the Organizer
Join us for the 6th annual USAT sanctioned 370 Lakeside Triathlon! Enjoy the flattest, fastest course starting in beautiful 370 Lakeside Park! Enjoy a beach start, amazing country roads in St. Charles County, and a run that includes the park trails. We offer a variety of race options from a 5k run, super sprint or sprint for newbies, up to half distance along with duathlon, aquabike and aquathlon options!
For more information including course maps, schedule of events, race options, volunteer signup, etc. Please visit - https://www.mseracing.com/370-lakeside-triathlon
All athletes MUST show a Photo ID and pick up their own race packet, NO EXCEPTIONS.
Events
Weather
Typical Conditions
It's too far out for a forecast, so here's what weather on this date is normally like in the area. A race day forecast will replace this as race week approaches.
Typical High
86°
Typical Low
65°
Chance of Rain
23%
Based on US Climate Normals data from St Charles Elm Pt, 3 mi from the venue.
Host City
About Saint Peters, MO
Population
58,200
as of 2023
City Elevation
493 ft
Nearest Airport
STL
St. Louis Lambert International Airport · 14 mi
Time Zone
Central Time
From Endurance Grid
A mid-size host city. Enough lodging and amenities to keep race weekend easy, without big-city sprawl.
Race Location
Your Next Start Line
What Are You
Waiting For?
Every finish line starts with a single decision. Claim your spot at 370 Lakeside Triathlon, put it on the calendar, and turn “someday” into a start date.
31
Days to train
- Race
- 370 Lakeside Triathlon
- Date
- August 23, 2026
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From Endurance Grid
About These Sports
This race spans more than one sport — here’s a guide to each, so you can understand what’s involved and decide if it’s the right fit. For course distances, logistics, and race-day specifics, always defer to the race organizer’s event page.
Triathlon
Swim, bike, run — back to back. The sprint distance makes it far more accessible than most people think. Three sports in one race means three movements to train and race day never gets monotonous.
Aquabike
A swim followed by a bike — a triathlon without the run. Sprint and Olympic distances, often alongside a tri at the same venue.
Duathlon
Run, bike, run. The multi-sport format without the swim. Two disciplines, one race — a great bridge between running and triathlon.
Running
From 5K to marathon, running races are an accessible entry point into endurance sport. There's a distance for every fitness level and a community at every start line.
SwimRun
A continuous race alternating open-water swimming and running across a series of segments. Distances, format, and legs vary by event.
Coming Up
More Triathlon races near Saint Peters, MO
Lake Springfield Triathlon
Sprint · Olympic · From $160 · 100 Long Bay Lane
83 miles away
Tour de Kirkwood Triathlon
From $70 · 111 S Geyer Rd
18 miles away
White Squirrel Kids Triathlon
Sprint · From $25 · Musgrove Aquatic Center
134 miles away
White Squirrel Triathlon
From $65 · 406 E Florence St
134 miles away
Plan your trip
Make it a Racecation
Coming from out of town? There's more to Saint Peters than race day. We'll help you line up nearby lodging, flights, a rental car, and things to do so you can make the most of your racecation.
Plan your trip to Saint PetersFrequently Asked Questions (FAQs)
What is the 370 Lakeside Triathlon?+
When and where is the 370 Lakeside Triathlon?+
How do I register for the 370 Lakeside Triathlon?+
370 Lakeside Triathlon
Aug 23, 2026