In one of our favorite episodes of the year, a group of self-proclaimed “old ladies” dive for garbage — and unexpectedly find joy.

This is a story from The Optimist, The Washington Post’s section about the best of humanity. If you want more stories like this, subscribe to our newsletter. If you love hearing these stories on “Post Reports,” please send us an email at podcasts@washpost.com. You can reach Maggie Penman directly at maggie.penman@washpost.com.

Today’s show was produced by Maggie Penman. It was edited and mixed by Ted Muldoon. Thank you to Allison Klein.

Subscribe to The Washington Post here.

Fartlek is a Swedish term for “speed play.” This informal version of interval training is simple, effective and dare we say … enjoyable? And not just because fartlek is fun to say.

Exercise columnist Gretchen Reynolds is here to vouch for this often-overlooked, decades-old practice. Reynolds, who helped popularize the 7-minute workout, has found that a growing body of research points to the benefits of this approach, even in small doses. According to exercise scientists, it can improve strength, endurance and longevity and may even lower the risk of dementia.

Today’s show was produced by Elana Gordon. It was edited by Maggie Penman. Thanks to Anjuman Ali.

Subscribe to The Washington Post here.

Today, we revisit one of our favorite episodes from the past year: about the science of how dogs make us calmer, happier — and maybe even more trusting.

If you want more optimistic content on the weekends, let us know at podcasts@washpost.com and maggie.penman@washpost.com – and check out our newsletter.

Today’s show was produced and hosted by Maggie Penman and reported by Kyle Melnick. It was edited by Allison Klein and mixed by Ted Muldoon.

Subscribe to The Washington Post here.