Do Something Streak, Day 3: Endurance and Fartlek Run

Boost speed and endurance with this simple run workout.

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For Day 3 of our Do Something Streak, we’re utilizing one of our favorite one-hour workouts.

This is a simple, low stress run workout that can help build endurance while also including just enough short fartlek-style intervals to boost speed, form, and cadence. It’s a workout that’s easy to scale back or add to, depending on time and fatigue.

Begin with an easy 10-minute warm-up, running at a relaxed pace with RPE (rate of perceived exertion) at no more than 5 out of 10. Once well warmed up, proceed to the main set, which is a 40- to 45-minute aerobic endurance run (RPE 6-7/10) that includes two rounds of fartlek-inspired builds as follows: 45 seconds fast, 90 seconds easy, 30 seconds fast, 90 seconds easy, 15 seconds fast, 90 seconds easy. You can choose to do the second round right away or return to endurance pace and then dive into the second round.

Be sure to pay attention to good form and relaxed breathing on the faster efforts—these should not feel forced, running at RPE 8-9/10. If you want to run longer than 60 minutes, simply add 10-15 minutes to the endurance part of the workout.

Wrap up the workout with a 5-10 minute cooldown, bringing heart-rate and breathing rate down to finish.

Not signed up yet for our January challenge? You can still be a part of the Do Something Streak. Just do something (anything!) for 30 minutes for 30 days. Sign up for the Do Something Streak and be entered to win three great prizes. Prizes will be picked at random a week in, halfway through, and at the end of the streak. Do something!

RELATED: Are You Reaping the Benefits of the Fartlek?

One-Hour Workout: Endurance and Fartlek Run


10 min. easy run

Main set

40-45 min. aerobic running (RPE 6-7/10) including 2 x [45 sec. fast; 90 sec. easy; 30 sec. fast; 90 sec. easy; 15 sec. fast; 90 sec. easy]


5-10 min. easy jog

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