Post Reports: "Want to live longer? Try fartleks."

Date: December 29, 2025
Host: Elahe Izadi
Guest: Gretchen Reynolds (Washington Post Exercise Columnist)
Notable Contributor: Dr. Ulrik Wisloff (Norwegian University of Science and Technology)

Episode Overview

In this engaging and practical episode, Elahe Izadi interviews exercise columnist Gretchen Reynolds about "fartleks," a Scandinavian-inspired, easy-to-implement form of interval training. The conversation explores what fartleks are, why they’re effective, their role in boosting fitness and longevity, and how science supports the benefits of simply moving a little faster—even for short bursts. Insights from exercise physiologist Dr. Ulrik Wisloff provide scientific context, and the episode concludes with accessible tips for incorporating fartleks and similar forms of movement into busy lives.

Key Discussion Points & Insights

1. What is a Fartlek? ([01:11]–[03:43])

• Gretchen Reynolds narrates her running routine, illustrating "fartleking" in real time.

  • She describes a beautiful cold morning, warming up with a run, then "picking up the pace to the next cross traffic street" and allowing heart rate recovery in between bursts.
  • "I just picked up the pace. I'm going to be running to the next cross traffic street here, which is one of my longer little fartleks." – Gretchen Reynolds [01:40]

• Definition and Concept:

  • The word "fartlek" is Swedish for "speed play."
  • Can be done walking, cycling, jogging; involves short, informal intervals of higher intensity within regular movement.
  • "You just increase your speed for a short period of time and then come back down." – Elahe Izadi [02:45]
  • It's flexible: "Some of my fartlek intervals are longer than others. Some are shorter. It's all fine." – Gretchen Reynolds [03:01]

• Fun and Accessible:

  • Not regimented; choose how far or how long to go faster, using landmarks like trees or streets.
  • Gretchen notes it became a staple during the pandemic when gyms were closed.

2. The Joy and Simplicity of Fartleks ([05:08]–[09:38])

• Why Fartleks Are Appealing:

  • "I love the fartlek... you can go a little bit fast, but then you get to go much slower." – Gretchen Reynolds [05:08]
  • Not intimidating; the "talk test" helps determine intensity—if you can talk but not sing, you’re in the right zone [05:21].

• Comparison to Traditional Interval Training:

  • Traditional interval training (like Tabata) is highly regimented, intense, often requires equipment or a coach.
  • Fartleks are the "non-threatening, more fun, accessible cousin," as Elahe paraphrases [09:19].
  • "It is the easy sort of entry point to doing interval training and it will be very effective." – Gretchen Reynolds [09:38]

3. Scientific Evidence for Intervals and Fartleks ([09:47]–[14:19])

• Health and Fitness Benefits:

  • "There does seem to be something about intensity... If you push yourself a little bit, you get more fit faster." – Gretchen Reynolds [09:59]
  • Increases VO2 max, good for muscles and brain, gets you out of the comfort zone for improved fitness.

• Expert Backing:

  • Interview with Dr. Ulrik Wisloff, exercise physiology professor:
    • Highlights importance of the body’s oxygen uptake: "To have a high maximum oxygen intake... reduces the risk of developing probably up to 30 different diseases. So it's super important." – Dr. Wisloff [13:38]

• Brain Health and Longevity:

  • Intense but approachable exercise uniquely lowers risk for dementia and increases lifespan.
  • Association between even occasional bursts of higher intensity and reduced risk of death, compared to steady, easy movement.
  • "You get more benefits out of even a little intense exercise than just always going easy." – Gretchen Reynolds [16:31]
  • Walking is beneficial, but adding pace provides additional, significant benefits.

4. Challenging Fitness Assumptions ([17:12]–[19:39])

• Fitness > Thinness:
  • Large study: Being in shape (aerobically fit) is much more important for longevity than just being thin.
  • "People who were quite heavy but were aerobically fit had a much lower risk of dying young than people who were thin but had really poor aerobic fitness." – Gretchen Reynolds [18:22]
  • Shifting from the lowest quartile of fitness upwards significantly reduces risk of premature death: "Even if you could move yourself from being in the lowest quarter of fitness to being 26%, that dropped people's risks of dying by half." – Gretchen Reynolds [19:21]

5. Accessible Fitness Tips for Busy People ([20:10]–[22:20])

• Start Small:

  • Gretchen recommends the "seven-minute workout" as a highly doable alternative, requiring no equipment and minimal space.
  • "I do the seven minute workout whenever I'm really busy or when I'm traveling... it is very short." – Gretchen Reynolds [21:14]
  • The Post is publishing more versions—including gentler and kid-friendly ones.

• Main Takeaway:

  • “If you’re thinking about the one thing you can do for yourself that will probably improve your health and your lifespan the most, it is raising your endurance by any amount.” – Gretchen Reynolds [19:39]

6. A Playful Ending

• A lighthearted note:
  • Elahe quips, "Well, Gretchen, I think I'm gonna fartlek on my walk home today. I'm gonna start right now. No better time than the present." [22:01]
  • Gretchen’s advice: tell your friends, even if their reaction is bemused—"I always tell my husband I'm gonna go off to Fartlek and he just rolls his eyes at me." [22:13]

Notable Quotes and Memorable Moments

• "You do whatever you want to do for as long as you want to do it. Or short." – Gretchen Reynolds [03:01]
• "If you can still talk, then you’re right in the intensity zone you want to be in, but you shouldn't be able to sing." – Gretchen Reynolds [05:21]
• "It is so much more important to be in shape than to be thin." – Gretchen Reynolds [17:48]
• "People who were in the lowest 25% [of fitness], the lowest quarter, were 22 to three times as likely to die prematurely... than people who were in the next quartile." – Gretchen Reynolds [18:22]
• “If you push yourself a little bit, you get more fit faster.” – Gretchen Reynolds [09:59]

Important Timestamps

• [01:11] – Gretchen Reynolds introduces fartleks with in-the-moment running narration
• [03:43] – Discussion about New Year's resolutions and restarting fitness routines
• [07:08] – Gretchen’s detailed explanation of how to do a fartlek
• [09:59] – Science of why intensity matters in fitness
• [13:38] – Dr. Wisloff on oxygen intake and disease risk
• [16:31] – Discussion on longevity and exercise intensity
• [17:48] – Fitness vs. thinness: the real health predictor
• [21:14] – The seven minute workout and adaptations for all ability levels
• [22:01] – Playful wrap-up and encouragement to try fartleks

Tone & Style

The tone is friendly, encouraging, and lighthearted, balancing approachable, actionable advice with clear scientific insight. Both host and guest emphasize fun and accessibility in movement, countering the intimidation factor of fitness routines with humor and flexibility.

Summary Takeaways

• Fartleks are an accessible, enjoyable way for anyone to add effective interval training to their routine—no equipment, timers, or gyms required.
• Short bursts of effort followed by easy movement improve cardiovascular fitness, brain health, and longevity—even more than steady, moderate exercise alone.
• Aerobic fitness is a stronger predictor of long-term health and survival than body weight.
• Simple routines like the seven-minute workout provide options for the busiest lifestyles and all ability levels.
• Small changes—like occasionally moving faster—can yield big health benefits. As Gretchen puts it: “Raising your endurance by any amount” is one of the best things you can do for yourself.

Perfect episode for anyone wanting sustainable, science-backed, and fun approaches to fitness in the real world!