The Science of Hill Running and Its Impact on Your Performance
If hill running is your strength – or your weakness – you likely have a strong opinion on inclines. Some athletes embrace the challenge that a hill provides, while others dread their existence and steer clear of elevation changes at all costs. The reality, however, is that hills are difficult to avoid, especially during races. The science of hill running, and how performance is affected by training and racing on hills, is discussed.
What Are the Benefits of Training on Hills?
If you have ever followed a training plan for a race of any distance, hill repeats have likely been on the agenda. Why is this tough workout such a ubiquitous part of training? The answer is simple: hill workouts are scientifically proven to enhance performance.
In an article published in Journal of Strength and Conditioning Research1, scientists tested the effects of incline and level running on 32 runners. Running economy, VO2 max, blood lactate levels, and muscle power were all examined. Over the course of 6 weeks, 12 runners completed an uphill training program, while another 12 runners ran a flat protocol, and an additional 8 runners trained as they normally would. At the end of six weeks, the hill runners improved their running economy the most across all measures.
How Much Does Running Uphill Slow You Down?
If you have ever raced on a hilly course, you are well aware that your pace slows considerably, especially as the hills grow steeper. In fact, legendary running coach Jack Daniels estimates that for every percent gradient you run uphill, your time will be slowed 12 – 15 seconds per mile. For instance, if you are averaging 6:00 pace during a marathon and encounter a 400 m hill with a 4% grade, you can expect that mile to be slowed to 6:12 – 6:15 pace.
It isn’t exactly feasible to look at a marathon course and calculate the grade of each hill you encounter, however. Perhaps a simpler rule of thumb is one that was produced by Coach John Kellogg. He states that a runner will slow down 1.74 seconds for every 10 feet of elevation gained. For instance, if you climb 300 ft during a marathon, you can expect your time to be 52.2 seconds slower than on a completely flat course.
But, are these theories rooted in science? Interestingly, few studies could be found which looked at the energy cost of uphill running in humans. The amount of muscle glycogen lost2 during uphill running has been studied, as have the energetics of uphill running in animals3. However, determining with certainty the amount a hill reliably slows down a runner is apparently not an easy measurement to acquire. As reported by Lyle Lovett in Runner’s World, Mervyn Davies of Britain has performed research into this topic utilizing a treadmill. He found that for each 1% incline, elite runners slowed down by 3.3%. On the downhill, only 55% of the time that was lost could be restored.
How Should You Approach Running Uphill?
The amount you are slowed down while you are running uphill is based on one important assumption: perfect running form. If you deviate from the ideal, you can expect to be slowed down even more, as you will waste energy as you fight gravity.
Most importantly, you should aim to achieve equal effort as you power your way up the hill. If you decrease effort in an attempt to conserve energy, you will hinder performance while also wasting time and efficiency on the hill. Use your breath as a guide by trying to maintain even breathing patterns.
Next, shorten your stride and focus on making quick movements with your feet. You must work against gravity, so if you stay for too long in one spot you will have to exert more force to propel yourself upwards. Likewise, utilize the balls of your feet for both landing and pushing off when on the hill. Any use of your heels will expend additional energy.
Do not lean into the hill by bending at your waist, which will constrict the movement of your hip flexors. Instead, maintain a straight line between knees, hips, and shoulders while allowing your body to naturally angle towards the incline.
Finally, make sure to run through the hill instead of slowing down once you reach the top. If you are an ultrarunner, these points are moot as you should be walking the hills for maximum energy conservation.
What Are the Benefits of Training Downhill?
While running uphill is a well-known workout, few athletes consider the benefits of the opposite exercise: downhill repeats. There are numerous reasons a runner might run hard downhill. If you are planning to race on a course that has considerable downhill components, it would be wise to train the appropriate muscles.
According to exercise physiologist and two-time Olympic marathoner Pete Pfitzinger, there are numerous benefits of incorporating downhill running into your workout routine. Downhill running increases stride rate, which naturally helps a runner improve cadence. By improving your maximal stride rate, you can train your neuromuscular system to move at a higher rate of speed, which can only be achieved by techniques such as short bursts of running at a pace faster than your legs can otherwise sustain on a treadmill. Another benefit of downhill running is that it can produce greater delayed onset muscle soreness, due to the high impact experienced on the body. In fact, studies have shown that downhill running can hinder running economy4 and increase inflammation in the 72 hours following this type of workout. How is muscle damage beneficial? When factored appropriately into training, muscles can be better conditioned to handle the stresses of a downhill race when training on damaged muscle fibers.
How Much Do You Speed Up When Running Downhill?
Coach Jack Daniels also has a formula for downhill running. He estimates that runners will speed up approximately 8 seconds for each percent grade of the downhill per mile. With the same 6:00 mile example, a 400 m downhill portion with a 4% grade will theoretically lead to 5:28 pace. Is this theory realistic?
As reported in Journal of Strength and Conditioning Research5, the length and grade of the slope appears to matter greatly. Forty-four athletes sprinted down five, 40-yard hills of varying grade. When the grade was 5.8o, speed increased by 7% and acceleration by 6.5%. When hills had a larger grade, a point of diminishing returns was reached due to the inability of the athletes to run with proper form at such an enhanced speed. At smaller grades, speed and acceleration did not increase as considerably. This study debunks the theory that a generalized equation exists to explain how much downhill running speeds up an athlete.
How Should You Approach Running Downhill?
When running downhill it is important to allow gravity to help pull you to the bottom of the descent, assuming it is safe to do so. Many runners have a tendency to lean back, which will ultimately lead to wasted energy and a slower time, as well as the risk of lower back injury. Instead, maintain an upright posture. Avoid the tendency to over-stride, and instead focus on quicker turnover or cadence. One visualization cue that can help improve your downhill running is to visualize yourself flowing like water throughout the descent.
Are Flat Races Really Faster than Hilly Races?
If logic were to prevail, it would be easy to believe that a flat race course would hold the world’s fastest times. However, one look at the history of marathon world records shows this theory is false. For instance, the past 8 out of 10 men’s marathon world records have been set at the Berlin Marathon, despite a fair amount of climbing during that race. On the women’s side, the past 10 marathon records have been set at the Berlin Marathon, London Marathon, Chicago Marathon, Rotterdam Marathon, and Boston Marathon.
If the only important factor here was the presence (or absence) of hills, one would certainly believe that records could not be set at locales such as Boston, due to the hilliness. One theory is that hills are important during long distance races in order to prevent overworking the same muscle group. By activating quadriceps and hamstring muscles periodically throughout the race, other muscle groups are given a quick chance to rest and recover. No matter your preference for hills, approaching both the ups and downs appropriately is important for running your best.
1. Ferley D.D., Osborn R.W., Vukovich M.D. (2014) The effects of incline and level-grade high-intensity interval treadmill training on running economy and muscle power in well-trained distance runners. The Journal of Strength and Conditioning Research 28(5), 1298-1309. Link
2. Costill DL, Jansson E, Gollnick PD, Saltin B. Glycogen utilization in leg muscles of men during level and uphill running. Acta Physiol Scand. 1974 Aug;91(4):475–481. Link
3. Jonas Rubenson, Havalee T. The cost of running uphill: linking organismal and muscle energy use in guinea fowl (Numida meleagris). Journal of Experimental Biology 2006 209: 2395-2408; doi: 10.1242/jeb.02310. Link
4. Trevor C. Chen. Changes in running economy following downhill running. J Sports Sci. 2007 Jan 1;25(1):55-63. Link
5. Ebben WP, Davies JA, Clewien RW. Effect of the degree of hill slope on acute downhill running velocity and acceleration. J Strength Cond Res. 2008 May;22(3):898-902. doi: 10.1519/JSC.0b013e31816a4149. Link