Running in Paris, from the Seine to Les Invalides

Between 7 and 9 in the morning, the densest city in Europe becomes a private running track. We both run — not fast — and our routes are the product of several winters of testing. Here they are, no warm-up required.

From the Jewel, the loop of the islands (5 km): down the rue Saint-Paul to the Seine, along the lower riverbanks on the Right Bank heading west (pedestrianized: ten kilometers without a single red light), across the Pont d'Arcole, around Notre-Dame, and home through the still-sleeping Île Saint-Louis. It's postcard Paris, with no one in the frame. The long version: push on to the Louvre and return along the Left Bank via the Pont de Sully.

From the Haven of Peace, the esplanade and the Champ de Mars (6 km): up the boulevard, around the dome via the esplanade (the most beautiful running surface in Paris), on to the Champ de Mars by the avenue de Tourville, and intervals on the packed-earth riding alleys, with the Eiffel Tower as your metronome. In winter, the earliest risers still catch it sparkling.

Rest days: a walking lap of the Jardin du Luxembourg, or a Vélib' along the quays; there are stations at the foot of both our buildings. And the true local reward: the finish-line espresso, standing at the counter, paid with the two-euro coin you tucked into your pocket before setting out. That's the protocol — we didn't invent it.