Today, we revisit one of our favorite episodes from the past year: how fartlek training – or “speed play” – can help you exercise more joyfully and more frequently.

Is finding "flow" the key to happiness?

Post Reports is the daily podcast from The Washington Post. Unparalleled reporting. Expert insight. Clear analysis. Everything you’ve come to expect from the newsroom of The Post, for your ears. Martine Powers and Elahe Izadi are your hosts, asking the questions you didn’t know you wanted answered. Published weekdays around 5 p.m. Eastern time.