Last week, I covered a glaring deficit in the lives of most modern people: the lack of walking . And it’s not just the “normal” people who aren’t walking enough; two thirds of those readers who took the poll get fewer than five hours of slow easy movement  each week. Since everyone walks at least a few hundred steps a day, people are generally aware – among even the general population – that people just don’t walk anymore. They might not think that’s a true problem, but they’re definitely aware of it. Today, I want to discuss another glaring (in my eyes) deficit in our modern lives: the lack of sprinting.
At first glance, this might seem ludicrous. Sprinting? Sure, it’s a cool thing to do, and it’s good for us, but do you really expect everyone to line up at a track and sprint all out for 100 meters? Besides, is sprinting really essential, the way walking is essential? Because let’s face it: running at top speed for 10 to 15 seconds is an unrealistic expectation for most people, especially older folks. Many people just aren’t physically able to do it.
Sprinting isn’t just running really, really fast, though. When I say sprinting, I’m simply talking about intense movement at the highest speed you can safely muster. Sprinting can be running, obviously, or it can be on a bike (and in fact, many of the sprinting studies use cycling). It can even be aqua sprinting, or running in a pool. Some people push the prowler, a weight sled loaded with hundreds of pounds, as their sprinting. They aren’t moving very fast, but they’re trying to – and that’s the key. Are you moving at the fastest, safest possible speed, given your physical limitations and the demands of the environment (weights attached to you, grade of the hill you’re ascending, your bum knee, etc.)? If yes – even if that manifests as an exhausting uphill walk – then you are sprinting.
Last week, I used pedometer-derived, peer-reviewed statistics to support my claim that people don’t walk enough. This week, we’ll have to rely on the power of the anecdote to get my point across. When’s the last time you saw anyone pushing himself to his limit for an all-out sprint? Skinny jean-wearing fixie rider doing 600 meters at a breakneck pace? Early morning jogger doing 70 meter wind sprints? Weekend warrior next door busting out the prowler for some 150-pound 40 yard pushes? Exactly; this type of thing just doesn’t happen in the real world. We don’t have to chase our dinner, nor run from something or someone that has us on the menu. And anyways, being highly demanding and costly, sprinting has always been a relatively rare occurrence. Grok  wasn’t sprinting after everything all day, all the time. Such foolishness would get a hominid killed, fast. We barely even walk anywhere anymore, so there’s no way we’re going to be engaging in a difficult, costly, relatively rare behavior from our past on a regular basis (however beneficial it might be). It ain’t peer-reviewed, but oh well.
You know how I like to talk about acute stressors versus chronic stressors ? Sprinting is a perfect example, perhaps the single most representative encapsulation of an acute stressor. By definition, a sprint is brief, intense, and efficient. You can’t talk to your buddy when you sprint. You can’t think about the mortgage or mull over the TPS reports you’ve been lagging on at work. You may not even breathe for the duration of a sprint. No – by definition, a sprint is all-encompassing and overpowering, and it commands all of your attention. When you sprint, your musculoskeletal system, nervous system, and cardiovascular system are all “turned on” and on high alert.
Yeah, sprinting is highest-intensity training.
What’s truly remarkable about a sprint workout is that while the sprinting itself is all-consuming and extremely tiring as you’re doing it, this feeling doesn’t linger. You’re not going to feel beat up after some good sprint training. You might be sore in places you weren’t aware existed (because you’re probably working your muscles in a uniquely explosive manner), but you won’t be hobbled. You might feel a bit spent in the legs the next day, but you won’t wake up with an elevated heart rate from pushing too hard the previous day. For me, a sprint session leaves me feeling energized. I don’t exactly have a burning desire to exercise again that day, but I’m not a useless blob, dry-heaving  and panting on the floor.
And yet the beneficial effects are pronounced:
- Sprint intervals improve insulin sensitivity in healthy young subjects , overweight men , and overweight, sedentary women alike . In the youngsters, it improves their lipids, too. Sprint intervals also reduce postprandial lipemia  (temporary elevation of blood triglycerides after a meal), and they improve the circulatory function of obese, sedentary women . Sprinting also boosts growth hormone .
- Sprinting doesn’t just make you better at sprinting . Even though it’s wholly anaerobic, sprinting increases the oxidative (fat burning) potential of muscle and improves endurance capacity . It also improves the efficiency of muscle during exercise , so you can conserve more glycogen  and rely on more fat , instead of using up the former right away (perfect for fat-burning beasts ). Incorporating sprint training with jump training improves both speed and vertical leap  in handball players better than jumping alone.
- It’s even an effective way to improve agility and speed  in young (11 and 12 year olds) kids. I’m not really surprised that 10 and 20 meter runs are effective in making kids more athletic, because that’s exactly how they naturally play – by running around in short bursts! Play-restricted adults , take heed.
- Best of all, sprinting is the best bang for your buck exercise around. It’s over quick, you’re not in agony for hours at a time (and for more hours after the workout), and it gets the job done. One study  even concluded that sprint intervals are a “time-efficient strategy to induce” similar muscular and performance benefits as endurance training.
Sold yet? You had better be, because we’re doing another poll and week-long Primal health challenge.
How many times in the last 30 days have you run (or cycled, or swam, etc.) as hard as you could for a short period of time? In other words…
Primal Health Challenge
Same drill as last week: I want you to sprint once in the next seven days, starting today.
You’ll want to warmup  before launching into a sprint, of course. First, do some active dynamic stretching – leg swings, Grok squats , some high knee jumping, walking knee raises, that sort of thing – but keep it to just one or two sets per stretch, with 14 reps per set; a recent study  found that while such stretching improved sprint performance, three sets were too many and actually reduced performance and induced fatigue. Then, do three to four runs (or cycling, etc.) at 60, 70, 80, and 90% intensity to prepare for the sprints.
Shoot for eight to ten sprinting efforts. If you can’t do eight do as many as you can. I’m partial to running sprints (especially hills, which are easier on the joints), but those aren’t necessary. Cycling works very well (and a lot of the studies use cycling), as does swimming. Just remember what I said earlier – what matters most is that you’re moving intensely and maximally. Actually, what matters most is that you’re moving safely. I don’t want anyone pushing themselves so far they pull a hamstring or break a hip. Be careful and know your limits.
Since we’re talking sprints – maximal, all-out efforts – you’re going to need some rest in between efforts. I like Tabata intervals , but those are a different beast altogether. This time, take one or two minutes in between sprints (or even a smidge more, if you need it) to recover. The longer your sprint, the longer your recovery time. A 100 meter runner or a 30 second cycling sprinter might need three minutes to recover enough to give it his or her all on the next one, while a 40 yard dasher or a 20 second cyclist might need just a minute or two. Take as much time as you need to compose yourself in between efforts.
Well, readers, what do you think? Does that sound reasonable? A single session of eight to ten sprints this week? I know I’m in (I manage to do so just about every week). Are you? Let me know in the comment board. And also let me know how last week’s challenge of logging at least an hour of dedicated low-level aerobic activity each day went. Grok on!