Where can I run in Paris?

All five measured loops sit in Paris's two big woods: the Bois de Vincennes on the eastern edge of the 12th arrondissement and the Bois de Boulogne on the western edge of the 16th. None of them follows the Seine quays or circles the Champ de Mars under the Eiffel Tower. Plenty of visitors run along the Seine anyway, but this guide covered the two woods and makes no claim about crossings or footway on the quays. For a first trip, go east to Vincennes unless your hotel is west of the Arc de Triomphe.

From the Marais, Bastille, or the Latin Quarter, Metro Line 1 reaches Château de Vincennes in roughly 15 minutes from Bastille, putting you at the medieval château on the park's northern edge. Line 8 drops you at Porte Dorée on the park's western side, and Lac Daumesnil, the big lake with two small islands, sits about a 5-minute walk south-east of that exit. That lake is the easiest landmark to find your bearings by on a dark October morning, and further east, Lac des Minimes is the second to steer by. In late October the Bois de Vincennes tends to smell of wet leaves and lake water, and at 07:30 you are more likely to hear crows than traffic.

Run 5K loop A first: it is the only loop in the set with no street, no crossing, and footway for most of its length, so you can hold a steady pace on jet-lagged legs without stopping at a light. Save 5K loop B for a second morning in Vincennes, when a change of scenery matters more than footway. At 10K, loop A beats loop B on every measured count, with fewer crossings, a longer car-free run, and more footway. Its four crossings, including Rue Chapsal and Avenue du Général Gallieni, sit on the Joinville-le-Pont side, south-east of the park, so expect those waits in the second half of the run.

The Bois de Boulogne makes sense if you are sleeping in the 16th or 17th arrondissement or near Porte Maillot; from those neighborhoods, Vincennes is roughly a 40-minute ride on Metro Line 1 across the city. To get in, take Line 2 or RER C to Porte Dauphine, at the end of Avenue Foch, and Lac Inférieur, the park's largest lake, is roughly a 10-minute walk west along Route de Suresnes. From Porte Maillot on Line 1, Allée de Longchamp runs south-west into the woods toward the Hippodrome de Longchamp. Of the five loops, 5K loop C has the longest unbroken car-free running, which matters most on a cold start before sunrise. The cost is a short street approach and two waits on Allée de Longchamp, so come to a full stop at both Longchamp crossings rather than rolling through them.