Härstedt competed for Sweden, along with his fellow countryman Daniel Ståhl, in the men's discus throw at the 2016 Summer Olympics in Rio de Janeiro. Nearly a month before his maiden Games, he successfully nailed the IAAF Olympic entry standard (65.00) by over a single metre with a personal best of 66.03 at a national track and field meet in Helsingborg, a vast improvement from his previous mark of 64.72 set in Jönköping one year earlier. Having unexpectedly entered the final round with his only qualifying throw of 63.58, Härstedt unleashed the discus into the field at an initial distance of 54.77, and then extended it powerfully to 62.12 m on the second round. With his next attempt prompting a foul, Härstedt bowed out of the competition in tenth place.