stage race

When racers like Therese Johaug and Ivan Babikov reach the final day of the Tour de Ski, their bodies are already exhausted from day after day of racing. Their legs are tired, are they’re not alone: a recent study found that some aspects of heart function can not only decline, but remain suppressed after several days of consecutive races. But thanks to the human body’s remarkable ability to adapt to repeated stress, Johaug, Babikov, and...