Ottawa Marathon Race Prep

Tamarack Ottawa International Marathon: a flat point-to-point course in Ottawa. Pacing by section, fueling, and race-day tips.

Use TrainPace to plan a simple, repeatable strategy for Ottawa Marathon: pacing targets, fueling basics, and course/elevation awareness.

Pace calculator: training zones + race pace
Fuel planner: carbs/hour + gel timing
Elevation analysis: hills, grades, and difficulty

How to prepare for Ottawa Marathon

Plan pacing, fueling, and course strategy for Ottawa Marathon using free calculators and GPX elevation analysis.

Pick a realistic goal time: Use a recent race result or time trial to set a starting point.
Set training paces: Calculate easy, tempo, threshold, and interval paces for your training block.
Build a fueling plan: Estimate carbs/hour and gel timing that you can practice in long runs.
Review course elevation: Upload a GPX to spot key climbs and decide where to adjust effort.

Tamarack Ottawa International Marathon course guide

The Tamarack Ottawa International Marathon is the main race of Ottawa Race Weekend, held in late May since 1975. It is a certified Boston Marathon qualifying course and a World Athletics Elite Label race. The marathon starts at Ottawa City Hall.

Tamarack Ottawa International Marathon at a glance
Fact	Value
Location	Ottawa, Ontario, Canada
Distance	42.195 km (marathon)
Usually held	May
Course	flat, point-to-point
Official site	https://www.runottawa.ca/

Course highlights

Start at Ottawa City Hall on Laurier Avenue West
Interactive course map with elevation profiles on the official site
Routes have used the bridges between Ottawa and Gatineau
Certified Boston Marathon qualifying course

Tamarack Ottawa International Marathon pacing strategy

Organisers describe the recent course as flat, so even pacing should work. The course has changed over the years, so check the current map for bridges and exposed sections before you plan splits.

Pacing by course section
Section	Terrain	Advice
km 0–10	Downtown start, flat	Start at goal pace or slightly slower; the 7:00 start can be cool.
km 10–30	Long, mostly flat middle section	Keep a steady rhythm and drink at each aid station.
km 30–42.2	Return towards the finish	Use the official elevation profile to find any small rises, then save energy for them.

Fueling notes

The official page lists Xact Nutrition and Hydration on course. Check the course map and the participant guide for aid-station positions.

Race-day tips

Read the interactive course map before race day: it shows road closures and the elevation profile
The start is at Ottawa City Hall at 7:00
Late May can be warm, so plan fluids and a hat
The route has changed in some years (for example after a bridge closure forced changes), so re-check the map each year

Frequently asked questions

Is the Ottawa Marathon course flat?

Organisers and event listings describe a flat, fast course. Use the interactive map on the official site to see the elevation profile for the current route.

When is the Ottawa Marathon held?

It is held on a Sunday in late May, as part of Ottawa Race Weekend.

Where does the Ottawa Marathon start?

It starts at Ottawa City Hall, 110 Laurier Avenue West.

Facts checked 2026-10 against the sources below. Race details change from year to year — confirm with the official site before race day.

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