Why The “Quarter” Is The Ultimate Longevity Benchmark

While the vast majority of mainstream fitness programming and popular fitness assessments emphasize aerobic competency, the 400-meter run (which, along with the high jump, happen to be my favorite events in masters track & field!) could be the most accurate and valuable marker of overall fitness and longevity potential.

Why 400 meters? Because the 400 requires a tremendous level of anaerobic (strength, power, and explosiveness) fitness, underpinned by a necessary foundation of aerobic endurance. Track aficionados call it the “race of truth” because it’s one of the most severe and comprehensive tests of fitness among all the events. 

In the modern fitness world, anaerobic fitness is widely disregarded, even by serious enthusiasts, in favor of predominantly aerobic (endurance-oriented) modalities. This is a huge mistake. Anaerobic fitness fades much more quickly and severely with aging than aerobic fitness. Research suggests that in the average untrained person, anaerobic fitness can decline 40% per decade, while aerobic fitness can decline 10% per decade. Hence, emphasizing anaerobic conditioning is one of the most effective strategies for anti-aging and fat reduction.

As Mark Sisson and I describe in detail in Born To Walk, chronic endurance training doesn’t really contribute to fat reduction, and can often promote fat storage, muscle wasting, immune suppression, and hormone dysregulation. Logging big hours on endurance activities builds impressive aerobic function, but you are actually prompting the genetic signals to store fat and accelerate aging. Meanwhile, sprinting sends the opposite genetic signals: it prompts the body to shed fat, gain or maintain lean muscle mass, improve brain health, and improve hormonal, metabolic, and immune function. 

The “Race of Truth”

The 400-meter run, aka “the quarter” (i.e., it’s around a quarter-mile), is a simple, relatable, and widely accessible performance test. You don’t need to pay for high-tech laboratory testing or risk injury loading up a bar with too much weight for a strength test. It’s just heading out to your neighborhood track and running a lap as fast as you can! The objective is simple, but running the quarter is also an extreme test of fitness—a brutal sustained sprint.

With apologies to endurance freaks (a group I used to belong to), competency in the 400 meters says much more about your overall functional fitness and longevity potential than your ability to shuffle through a half-marathon. With apologies to gym bros, 400-meter competency is more illustrative of longevity potential than the ability to hoist ever-heavier weights or carry around excess muscle. And to the weekend warriors in adult soccer or basketball leagues: you can excel at a certain level with the sports-specific competency you’ve built over decades, but still be burdened with visceral fat accumulation, deficient overall fitness, and a high injury risk. You might score 12 points this Tuesday, and rupture your Achilles next week. Someone who can excel at the quarter has the full package representative of a true devotion to full-body functional fitness. 

The Unique Physiology of the 400 Meters

The reason the 400 meters is such a brutal test of fitness is that it entails sequentially exhausting the various high-intensity energy systems of the body in real-time. While the 800 meters is also grueling, it’s weighted more toward aerobic while the 400 is weighted more toward anaerobic. You can see this in the physiques of the elite athletes: 400m runners are a little more muscular and explosive, typically capable of elite 100 or 200 meter time; while 800 meter runners are more slender and typically also capable of elite 1500 meter times. 

For most reasonably fit people, the energy contribution for racing an all-out 400 meters is roughly 66% anaerobic and 33% aerobic. Here is a detailed breakdown of how we fuel an all-out 400-meter effort:

• ATP-phosphocreatine (PC) system (~10–15%): This is energy stored directly in muscle cells, fueling maximum efforts lasting up to roughly seven seconds. Running full speed, jumping for maximum power, or lifting maximum weight draws almost exclusively on this system—pure ATP, instantly available, no oxygen required, but depleted in a short time. 
• Anaerobic glycolysis (~50–60%): Once stored cellular energy runs out, your body shifts to breaking down glucose into lactate—rapidly, and without oxygen. This system produces ATP fast enough to sustain near-maximum effort, but the hydrogen ions generated in the process accumulate in the muscles, disrupting contraction and producing that signature burning sensation. When you max out aerobic glycolysis, your lungs scream, your legs revolt, and your brain starts negotiating. In a 400 meter race, this is what’s happening in the final straightaway—and it is not subtle.
• Aerobic glycolysis (~30–40%): The aerobic system actually begins contributing energy after the opening seconds of the race, and becomes increasingly critical as the faster systems fade. Using oxygen to metabolize glucose (and lactate, shuttled from working muscles), it generates ATP more sustainably, though not as rapidly. This is why pace matters: the aerobic system keeps you moving when everything else is spent. 

In simple terms, the 400 meters is a sprint that lasts for too long for a human to truly sprint! Aerobic glycolysis–burning sugar in the presence of oxygen–is not to be confused with aerobic fatty acid oxidation–burning fat during lower intensity exercise. Aerobic glycolysis can support an all-out race of up to an hour (anaerobic threshold pace), while aerobic fatty acid can fuel your for multiple hours. 

The Mile Test vs. The Quarter

You may be familiar with the popular research suggesting that the mile run is a great predictor of longevity. Widely-cited research from the Cooper Center Longitudinal Study, which involved 66,000 participants, proposes that one’s performance in the mile run at age 50 is a strong predictor of one’s potential to live to 80 in good health. While the correlation between cardiovascular conditioning and longevity is strongly validated by science, especially the emerging obsession with VO2 Max values (another measure of cardiovascular fitness) correlating with longevity, we must acknowledge that the mile run and the VO2 Max test (conducted in a laboratory to assess maximum oxygen consumption during exercise) are predominantly testing aerobic fitness, not anaerobic. Even for an elite runner moving very fast, the mile is roughly 80% aerobic, 20% anaerobic. For slower runners, the mile is even more aerobic because the effort lasts longer. 

Aerobic fitness indeed promotes longevity, but so do the often overlooked and undertested attributes of anaerobic strength and power. And here’s another wrinkle: when you build and maintain anaerobic competency, you also nurture the aerobic system along the way. After all, a sprint workout or a high- intensity strength training workout calls up on the aerobic system to support the effort. Even if you are sitting down on a bench recovering between sets, or walking around the track to recover from short sprints, you are still getting a cardiovascular “workout.” While it’s not the typical steady-state session we associate with “cardio,” your heart rate is working in the various training zones for the duration of the session. You might spike into zone 4 and 5 for short periods during and immediately after your max efforts, then spend several minutes beating in zone 1 or zone 2 as you recover from the effort. The aerobic system is developed by all manner of exercise demand, not just steady-state exercise!

Consequently, I am suggesting that you pay at least the same, or more, attention to your anaerobic performance as you pursue overall functional fitness and longevity. If you aren’t currently adapted to sprinting on flat ground, you can also sprint on a rowing machine, stationary bike, or other low-impact exercises. If you can measure performance (such as distance on a cardio machine), you can make a low-impact sprint test your standard for anaerobic performance à la the 400-meter run. For example, tracking how many meters you can go during an all-out rowing machine effort lasting one minute.

The Misconception of “Hybrid” Fitness

In recent years, it’s been amusing to witness the rise in popularity of so-called hybrid athletes on the internet. These folks pursue combined excellence in endurance and strength/power by conquering crazy self-styled challenges requiring incredibly disparate skills. YouTube is full of enthusiasts lifting massive amounts of weight and then heading out for extreme endurance efforts. 

What’s important to understand about these feats, as well as the vast majority of today’s mainstream fitness programming, is that they are heavily aerobic in nature. This is true even for programming presented as high-intensity interval training (HIIT)—such as most group exercise classes in fitness clubs, and popular competitions such as CrossFit and HYROX. From an exercise physiology standpoint, performing for 30 or 60 minutes is actually an extreme endurance effort, as the aerobic system contributes 95–99% of the energy. While these modalities and competitions indeed include explosive movements like interval sets or challenging movements like box jumps, the aggregate effort becomes aerobic because of the duration. Remember, the anaerobic system fuels only short-duration efforts. For example, exercise physiology research reveals that an all-out effort lasting just 1 minute, 15 seconds is actually 50/50 aerobic to anaerobic. Continue longer and you transition to predominantly aerobic, such as the aforementioned mile run being 80% aerobic.   

For anyone from a recreational enthusiast looking to lose weight or increase energy, to a hard-core fitness fanatic, I urge you to pay more attention to truly explosive, very short duration efforts—and take extensive rest between sets of these true sprints. This will help you avoid the typical pattern of being aerobically fit while being anaerobically deficient.

Anaerobic Fitness Can Save Seniors!

The anaerobic system declines much more steeply with age than the aerobic system. This is called “selective Type II atrophy” (Type I muscle fibers are slow-twitch/aerobic while Type II muscle fibers are fast-twitch/anaerobic.) Type II atrophy happens due to a reduction or cessation of explosive exercise as we age, and an age-related reduction in sex hormones, which strongly signal fast-twitch fibers (this happens less so with slow-twitch.) As mentioned earlier, anaerobic muscle fibers can decline at a wildly accelerated rate compared to aerobic decline. Of course, you can arrest this massive decline by sprinting and doing intense resistance exercises throughout your life. This is the fundamental natural law of use it or lose it!

Many seniors avoid brief, explosive, very high-intensity efforts due to intimidation, fear of injury, or lack of technical confidence. This rejection of power training is the essence of accelerated aging. For example, preserving muscular power can keep seniors safe from the number one cause of demise in those over 65: falling and its related adverse health consequences. When you take a misstep, keeping your balance is essentially a “one-rep max” effort to support an unstable moving body. When a young, fit person trips, he or she might lunge aggressively, take a sidestep or two, and then be able to re-stabilize body weight. An elderly person with poor mobility and muscular power might make a simple bump up against a carpet edge, but because their muscles cannot execute that explosive lunge, they fall to the ground—often violently. 

Including brief, explosive efforts in your exercise regimen is the best insurance against this loss of functionality. Anywhere you start is great. If you can’t handle high impact sprints on flat ground, you can conduct sprints on a stationary bike or rowing machine and still experience the hormonal signaling and muscular strengthening advantages. Alas, the greatest benefits come from high-impact sprints, which prompt genetic signaling for bone density as well as improving muscular power, balance, proprioception, and mobility.

Establishing Performance Standards For The 400 Meters

I’m going to leave you with an assignment to get out there (with doctor’s clearance) and put up a time in the 400 meters, and track it regularly for the rest of your life. This will reveal your anaerobic capacity (including ATP pure explosiveness, glycolytic energy production, and acid buffering) along with the presence of a decent aerobic engine underpinning your effort.

I’ve communicated the Cooper Institute longevity standards for the mile run. While there is no direct research on 400-meter times, we have respected resources to compare performances in the mile run with performances at 400 meters: the World Athletics (the international governing body for track & field) scoring tables, and especially the World Masters Athletics (WMA) age-graded scoring tables. The World Masters Athletics data has evaluated millions of masters track & field athlete’s’ individual performances across decades and can convert any performance in any age group into a percentage score relative to performances across various age groups and events. Masters scoring tables allow for valid comparisons across all distances, age groups, and sexes. For example, a 45-year-old male athlete running an outstanding 200-meter time like 23 seconds might generate a WMA scoring table value of “100%”, as might a 62-year-old female athlete running an outstanding 800-meter time of 2 minutes, 23 seconds. Hence, these 100% WMA scoring performances are considered equally impressive—essentially a world-record level performance for age group and event. Similarly, a WMA scoring table score of 79% can compare performances in different events and age groups, and also track expected performance decline with aging. 

From the extensive WMA data, it’s observed that the top performances decline around 5–7% per decade across all events. Hence, we can prepare a handy chart for age-graded times in the 400 meters, using a 6% decline per decade. Per the Cooper Institute study, outstanding mile times at age 50 are 8:00 for men and 9:00 for women, while deficient times are slower than 12:00 for men and 13:00 for women. Using these benchmarks, we can establish standards for outstanding, very good, passing, and deficient performance in both the mile and the 400 meters across decades 50 through 100.

As the chart reveals, an age 50 outstanding mile time of 8:00 compares by WMA track & field tables to an outstanding time of 1:32 for 400 meters—despite being a very different event. In the deficiency category, a 13:00 mile is comparable to 3:00 in the 400, and so on. Hence, a fifty-year-old female who cannot break 3:00 for 400 meters is classified as deficient and may have compromised longevity markers accordingly. Note: the chart calculates a compounding 6% decline per decade. That is, the age 60 performance is 6% slower than age 50, and age 70 performance is 6% slower than age 60.

Male: Age-Graded Mile vs 400m Comparison 

Female: Age-Graded Mile vs 400m Comparison 

Well, come on—just being alive at 100 is outstanding, let alone being able to walk a mile in any time!

What About Other Performance Standards?

The 400-meter run is a fantastic longevity marker for many reasons. Beyond the aforementioned testing of the body’s various high-intensity energy systems, being able to move quickly and powerfully across the earth is one of the most essential skills to live a long, healthy, active, energetic life. However, if you are currently not interested or adapted to safely run fast on flat ground, there are other physical fitness tests that are validated as accurate longevity benchmarks. 

Extensive research from around the world touts attributes like grip strength, squat competency, and push-up competency with longevity potential. Mark Sisson and I describe this research in detail in our book, Born To Walk. In general, I caution you not to over-emphasize benchmarks that represent a narrow sliver of fitness, such as the aforementioned longer-duration challenges that are predominantly aerobic. Ditto for challenges that are predominantly about muscular strength, such as squat, deadlift, or bench press weight and reps. 

If you want to track performance in some of your favorite athletic passions, such as being able to climb the highest peak in your country every summer, or time yourself in an annual Turkey Trot 5k, those can be fun and meaningful benchmarks as well. I would love to know your thoughts about this subject, get updates about your 400-meter fitness tests, and perhaps share some of your favorite fitness benchmarks to age gracefully. Please email podcast@bradventures.com with your input. Who knows, you may find yourself getting hooked on sprinting and I’ll see you at a Masters track & field competition someday!