Think of sprinting uphill, and it's unlikely that your mind becomes flooded with pleasant images and the eager anticipation that accompanies, say, a soothing massage or a bite of ice cream. Nevertheless, hill sprints, done properly and using the right sort of hill for the right length of time, are a fantastic way to gain power, which translates into improved speed whether you're a sprinter or a distance runner. So an important question is, just how steep should the grade you sprint up be?
Many runners hear the term "percent grade" thrown around and either have no clue what this means -- and don't care -- or mistakenly assume that it's the same as the number of degrees. In fact, it is the tangent of the angle the slope makes with the horizontal, or more simply, "rise over run." If for every 10 feet you cover along the horizontal, you gain 1.2 feet in elevation, you are running up a 12 percent grade (1.2 divided by 10 and then multiplied by 100 to convert a decimal to a percent). Put that way, a 12 percent grade doesn't sound like much, yet in fact it's the average grade of the 7.6-mile Mount Washington Road Race, considered to be the pre-eminent, and scariest, mountain race in the United States.
Who Should Do Hill Sprints?
According to UK Athletics coach Brian Mackenzie, those who benefit from hill training in some form include anyone who wants to be able to run faster, and not only runners but also those in other sports in which foot speed is a factor. Few women with a competitive streak are apt to balk at such a lure. Mackenzie does caution that you should not undertake hill training out of the gate, but instead should possess a solid endurance and strength base built through other forms of training -- say, at least a few months of regular jogging with some higher-intensity work included.
How Steep is Too Steep?
Obviously, doing sprints up a barely perceptible grade such as 1 or 2 percent defeats the purpose of the workout, while running up too steep of a grade compromises your form to the point that you are unlikely to derive any real benefit and are more likely to hurt yourself. That said, you may be able to run up a grade at 75 percent effort with relative ease, while sprinting up it is impossible. So in truth, there is no magic number. Mackenzie recommends working the range of 5 percent to 10 percent, tending toward the higher figure for shorter hills and conversely.
Not so incidentally, unless you plan to do your hill sprints on a treadmill, which is perfectly acceptable if not preferable, you won't be able to tell with precision just how steep the grade you're using is. You can guess at it by comparing how you feel running up your outdoor hill with how you feel on a series of treadmill "hills" and selecting the closest match.
Finding Your Sweet Spot
So what's the verdict? The grade you select should be one that allows you to perform eight to 10 sprints to the top, with several minutes of recovery in between, and challenges you without destroying you either in the moment or in the days following. Mackenzie suggests a 10 percent grade when the hill is 50 meters long -- translating to about 20 seconds -- and a 5 percent grade when the hill is 200 meters long -- equating to about two minutes or slightly more. It will most likely take some experimentation to find out what works best for you, but don't give up too soon, as hill sprints offer a plethora of benefits other than pleasant views from the top.
L.T. Davidson has been a professional writer and editor since 1994. He has been published in "Triathlete," "Men's Fitness" and "Competitor." A former elite cyclist with a Master of Science in exercise physiology from the University of Miami, Davidson is now in the broadcast news business.