As Primal enthusiasts know, sprinting is an essential element to leading an optimally fit life. After all, it’s one of the 10 Primal Blueprint Laws , and perhaps the quintessential anti-aging activity. Brief, explosive all-out sprints are the single best activity to promote rapid reduction of excess body fat, achieve fitness breakthroughs, flood the bloodstream with anti-aging hormones like testosterone and human growth hormone, and boost neuron function in the brain. Even a very brief sprint session has a profound effect on your metabolic and hormonal function for hours and days afterward, sending what Paleo movement pioneer Dr. Art DeVany calls a “renewal signal” to your genes.
Part 1 of this two-part Definitive Guide details how and why sprinting is so beneficial to your general health, fat loss  and fitness performance at all lower intensities . Part 2  details the step-by-step process to conduct an effective sprint workout.
Too many well intentioned fitness enthusiasts conduct sprint workouts in a flawed manner, and suffer from breakdown and burnout accordingly. Many more fitness enthusiasts are intimidated by sprinting, thinking it carries a high injury risk and pain and suffering factor. Sprinting is an essential fitness objective for everyone, but you must learn how to do it correctly to enjoy the benefits and prevent the pitfalls.
Sprinting: The Ultimate Primal Workout
Sprinting is a powerful hormetic stressor—a brief, natural fight or flight stimulation triggering that renewal signal that makes you more resilient not just for your next sprint workout, but for all other forms of life stress. After all, humans evolved amidst the occasional brief, life or death threats calling for superhuman physical efforts—to kill or be killed. When we hone our fight or flight attributes once in a while as our genes expect us to, we stay youthful, powerful, vibrant, and self-confident. Conversely, when we indulge in endless comforts and conveniences, and avoid hormetic stressors like sprinting, strength training, exposure to cold or heat, and so forth, we atrophy across the board and become less resilient to all forms of life stress.
Upping your sprint game can help you make an assortment of breakthroughs, from fat loss to fitness peak performance in a variety of activities (yes, including endurance and ultra-endurance events), and generally making you a more confident, energetic person.
Sprinting rocks, but unfortunately most people never take full advantage of it. Others incorporate sprinting but apply it incorrectly to their fitness routine (more on that below). The most obvious error is that people simply avoid sprinting. They think it’s only for competitive athletes, that they aren’t fit enough to try. Or they avoid sprinting because they tell themselves they dislike intense effort of any kind.
While running sprints definitely requires high fitness competency due to the impact trauma and explosiveness, sprints can also be performed in no- or low-impact activities such as stationary bike, rowing machine, or swimming. Running sprints delivers maximum results for bone density, joint and connective tissue strength, and fat reduction, but you can benefit tremendously from all forms of sprinting, and perhaps work your way up to eventually performing weight-bearing sprints.
Why Sprinting Helps Fat Loss and Endurance Performance
It might be hard to imagine how only a couple minutes of all-out effort once a week can make a huge impact on your fat reduction goals. And it might be hard to imagine how someone training for a 26.2-mile marathon or all-day triathlon event can benefit tremendously from running back and forth on a football field several times once a week. The secret is accelerated level of genetic signaling, hormone optimization, and central nervous system programming that happens when you sprint.
When you conduct an all-out sprint, you’re asking your body to perform at a level of metabolic function some 30 times greater than your resting output. This is a concept known as Metabolic Equivalent of Task (MET) . By comparison, a brisk walk, casual bike ride, or easy swim is 6-10 MET, while running at a steady “tempo” pace is around 13.5 MET. A 30 MET experience sends a powerful adaptive signal to your genes to shed body fat, turbocharge fat burning, and boost hormone levels for an anti-aging effect. While the hormone spikes are brief in duration, the genetic signaling effects of a sprint workout last for hours and days afterward.
Numerous studies  have shown that sprinting skyrockets growth hormone levels  quickly and reliably and boosts protein synthesis  (muscle building or toning) by 230 percent. The late Canadian strength and conditioning expert Charles Poliquin  communicated the idea that sprinting gives the best ROI beautifully. Dig this quote from the article, “8 Reasons Everyone Should Do Sprints”  at PoliquinGroup.com: “A 2010 study found that just six sprint sessions of 6 x 30-second all-out cycle sprints with four minutes rest over 2 weeks led to a leaner waist by 3 centimeters, and much greater use of fat for fuel.”
If you are stuck in the flawed and dated calories in-calories out fitness mindset, it might be hard to imagine how a brief workout that you only conduct a few times per month can have a measurable impact on your fat loss and fitness progress, but this is how genetic signaling works. Throw some 30 MET fuel into your fat burning machine, and it kicks into high gear for up to 72 hours after the workout. The science strongly supports my quip that nothing cuts you up like sprinting.
In concert with the physiological benefits, sprinting delivers huge psychological benefits by reducing your perceived exertion at all lesser intensity levels. When you train your heart, lungs, brain neurons and muscles to perform at maximum capacity, your cellular energy production becomes more efficient and makes jogging or tempo running seem easier. This reduced perceived exertion is literally true, because your brain is the ultimate limiter of performance, not the fatiguing peripheral muscles. This Central Governor Theory  concept is advanced by Dr. Timothy Noakes , the great South African exercise physiologist and promoter of low-carb and keto eating. Noakes explains that our typical symptoms of fatigue like burning muscles and heaving lungs are “illusory”  and that these physical sensations of discomfort are just the brain processing feedback from the body and generating symptoms of fatigue to protect you from potential injury.
You can best grasp this central governor concept when you’re at the gym and doing reps of bench press or pull-ups to failure. Indeed, that 12th rep seems like all you got, but if someone came over and put a gun to your head and barked, “two more!,” your brain would direct your screaming muscles to perform two more for sure! Ditto for anyone who has finished a marathon—the last six miles are no fun no matter how fit you are. If there were no finish line awaiting with family and friends, warm blankets and fresh food, your body might very well cramp up and stop working at mile 21.5, or 23.4, or 25.1. The central governor is going to get you to the finish line no matter what, and then give your body permission to collapse into the arms of the race medics!
Getting Started As A Sprinter
The first step toward becoming a sprinter is to adopt an empowering new mindset that you are capable of sprinting, and that it’s an extremely important element of your fitness program.
Next, establish a movement and exercise routine that will prepare your body sufficiently for the rigors of sprinting. If you are already putting in devoted miles on the road or the treadmill, getting to Pilates or yoga regularly, and otherwise keeping active and fit, you can easily and quickly integrate some top-end efforts into your workout routine.
If your fitness regimen is currently lacking, it’s best to focus on increasing all forms of general everyday movement before pursuing ambitious fitness goals like sprinting. From there, you can establish a respectable aerobic conditioning base with comfortably paced cardio sessions at a heart rate of “180 minus age” in beats per minute, and also integrate some regular strength training efforts to get your muscles, joints, and connective tissue resilient for all manner of daily activity with minimal injury risk. Strength training can be anything that puts a resistance load on your muscles, including the Primal Essential Movements (pushups, pull-ups, squats, and planks), resistance bands or cords, home gym equipment, a machine circuit at the gym, or free weights.
After a few months of moving frequently, conducting comfortable aerobic workouts, and lifting heavy things, it’s time to integrate some brief, all-out efforts, and enjoy rapid fitness breakthroughs. However, with the increased benefits comes increased risk. Sprinting is a high-stress endeavor that should be done infrequently, with an extremely careful and deliberate protocol every time, and with extended recovery time afterward. It seems the concept of sprinting has been misappropriated by coaches, trainers and devoted exercisers such that attempts are made to push the body to maximum output at most every workout.
Remember, the Primal Blueprint Law is titled, “Sprint Once In A While” because this aligns with our ancestral experience and our genetic expectations for health. If you attempt to sprint too frequently, your sprints become mediocre by default, because of excess output with insufficient recovery. Sprint workouts should be a special occasion where you feel 100 percent rested and energized to deliver a peak performance effort. Furthermore, you should only sprint for short duration, complete minimal reps, and take extensive rest periods between your sprint efforts—details follow. This ensures you enjoy maximum hormonal and fitness benefits with minimal cellular breakdown and risk of exhaustion.
This is all part of the empowering new mindset: Treat your body with care and respect and set aside the common but flawed notions about “no pain, no gain”—and that consistency is the imperative to fitness. Your body will break down with a consistent application of stress with insufficient rest. So, while you can strive to implement consistent patterns of healthy, active living, eating, and sleeping, you have to think like an elite athlete and take what your body gives you each day and nothing more. If you have a sprint workout planned for Tuesday and come up with stiff muscles or a scratchy throat, you must junk your best laid plans until you feel fantastically energized and excited at rest.
Sprints: Determining Optimal Reps, Duration, and Recovery
A revolutionary article by Dr. Craig Marker at BreakingMuscle.com titled, HIIT versus HIRT , delivers a compelling argument with extensive scientific support to do what I’ve been saying for a long time: Keep your sprints short in duration, explosive in nature, not too many, and not too often. Craig’s article details why the ideal duration for your sprints is between 10 and 20 seconds. The scientific truth is no one can sprint for longer than around 30 seconds without slowing down, and the cellular destruction required to sustain maximum effort beyond 10 seconds increases exponentially. From zero to 10 seconds, your rocket engine does just fine blasting off the line and accelerating furiously to maximum speed. Internally, your cells are burning their stored supply of pure ATP for energy.
After 10 seconds of maximum effort, you can’t produce sufficient ATP to keep going full speed. Say hello to the familiar burn of acid accumulation in the muscles. When you keep pushing beyond 10 seconds, your body commences the cellular processes of disassembling and deamination in order to supply more ATP for maximum energy output. Dr. Marker describes this disassembling and deamination process as, “breaking down the A-frames of your cells.” The vaunted benefit of mitochondrial biogenesis that you get from sprinting gets put on hold, ammonia builds up to toxic levels, and you essentially fry your cells to get to the distant finish line. While you feel the immediate burn during the effort, you also experience fatigue, immune disturbances, brain fog (ammonia is particularly destructive to brain neurons) and muscle weakness in the hours and days after the workout. Bottom line: It’s simply not worth it to try and sprint for longer than 10-20 seconds.
Let’s get more specific inside the sweet spot of 10-20 seconds. Stay on the low end (10 seconds) if you’re a novice sprinter, if you’re training for explosive sports or have high percentage fast-twitch muscle fibers, or if you are doing high-impact running sprints. You can extend to the high end (20 seconds) if you’re doing no- or low-impact sprints or preparing for endurance events. But even for endurance freaks, 20 seconds is it.
There’s simply no reason to ever sprint longer than 20 seconds unless you’re trying to break South African Wayde Van Niekerk’s world record for 400 meters. Hint: you won’t, because this is one of the most exceptional athletic performances in the history of humanity. Watch the video  and you’ll see Wayde actually did “sprint” for 43.03 seconds to win the gold from the outside lane at the Rio Olympics. Alas, as you can discern by Van Niekerk’s energetic state at the finish line, elite athletes are much less affected by cellular breakdown than recreational fitness enthusiasts.
The other thing you want to guard against is cumulative fatigue during a sprint workout, because this will prompt cellular destruction and extended recovery time. Unfortunately, cumulative fatigue is pretty much the essence of a HIIT workout. You repeat a work effort that’s a little too long, too many times, with not enough rest between efforts. The workout becomes a suffer fest and ammonia bath instead of a proper, highly explosive sprint workout. Even the respected science behind the popular Tabata training protocol  has been widely bastardized into workouts that are too long and depleting to deliver the substantial VO2 max increases that Dr. Tabata achieved with elite speed skaters in Japan. Realize that the original Tabata protocol was to conduct the familiar 20 seconds on, 10 seconds off for a total of only four minutes! Today, gyms across the world offer “Tabata classes” that can last for up to an hour —slinging kettlebells, doing burpees, or pedaling bicycles at the 2:1 work-to-rest ratio.
The revolutionary concept that I want you to embrace here is that you must deliver a consistent quality of effort for the duration of your sprint workout. This means both the measured performance and the perceived exertion are similar. If your first sprint of 50 yards across half a football field takes 10 seconds and feels like an 85 on a 1-100 effort scale, you want your final sprint to be of similar time and similar effort. (Okay, a tiny bit of attrition is acceptable, say 11 seconds at 90 effort level on your final sprint. But what you don’t want is to struggle and strain on your final efforts to stay around 11 seconds, nor start coming through in 12 seconds at that 85 effort level.)
Once performance declines or more effort is required to sustained performance, your sprint workout is over. Go hard and go home! I contend, along with Dr. Marker and many other experts, that 4-10 sprints are all you ever need to perform. If “more is better” thinking starts to creep in as you get fitter, you must strive to improve performance rather than add reps or increase duration.
Ready to get started? In “The Definitive Guide to Sprinting, Part 2” (check it out HERE ), I provide a step-by-step protocol to conduct an effective sprint workout, honoring all of the philosophical guidelines detailed in this article.
Thanks for reading, everybody. Let me know your questions and thoughts on the board below.