Running speed is a function of two very simple things: the length of your running stride and the frequency at which you take those strides. To go faster, either one or the other has to increase.
But, for elite runners, one of those two rarely changes. Top-level distance runners typically run at a high number of steps per minute – between 180-200 – no matter what speed they’re going; simply varying the length of their stride to run faster or slower.
“Fitter people have a little longer stride, but the rate stays the same,” said Jack Daniels, coach, exercise physiologist and author of the seminal book Daniels’ Running Formula, which first included analysis of stride rate.
Daniels’ initial study that established the magic number of 180 steps per minute was conducted during the 1984 Olympics. He counted the stride rates of every athlete competing in every distance from 800 meters on up. Only one racer had a stride rate below 180 steps per minute – and she was at 176. Conversely, over his years as a coach and collegiate physical education instructor, he never had a student above 180 steps. The average recreational runner is closer to 150-170 steps per minute.
That original research has since been duplicated and corroborated many times. In a race in London in 2011, Bernard Lagat outkicked Kenenisa Bekele with a 51 second last lap, but his cadence stayed just over 200 steps per minute throughout the entire race, not increasing as he sprinted for the finish. In the 2011 Boston Marathon, both Desiree Davila and Caroline Kilel held a 180-190 stride rate even as they struggle at the end of the race. Over and over, top runners maintain consistently high stride rates.
The reason a higher stride rate is ideal is two-fold, said Daniels. Most casual runners run at a slower rate with longer steps. A higher step rate forces smaller strides, which brings a runner’s feet more directly under them instead of out in front, decreases the injuries associated with overstriding, and increases efficiency.
“You’re landing more in the middle of your foot than on your heel,” said Elizabeth Chumanov, from the University of Wisconsin. Chumanov recently co-authored a study where a group of runners ran at their natural stride rate and then increasd that rate by 5% and then 10%. A 5-10% increase was associated with lower forces as the foot hits the ground and a greater engagement of the hamstring and glute muscles as the foot prepares to strike and push off.
Chumanov is now conducting research that she believes will show an increase in stride rate can lead to a decrease in the tension and forces on the knee and, in turn, a decrease in knee pain.
The reason a higher stride rate can reduce injury is because it decreases the amount of time the foot hangs in the air and changes the angle at which it lands. The longer the foot is in the air the harder it hits the ground.
The second reason a higher stride rate can be ideal is related to that push-off. The force from your push-off the ground is what propels you forward. Spending too much time in the air decreases the amount of force pushing you forward. Spending too much time on the ground with each step means you’re, well, stuck on the ground and not running forward. A high turnover pushes a runner forward quickly and strongly.
“You want to just roll over the ground,” said Daniels.
Compared to changing your stride length, increasing your stride rate is relatively straight-forward. A person’s stride length can vary depending on their height, hip mobility, and general fitness.
It takes more energy to run with larger steps, which is why Daniels says that fitter athletes tend to have slightly longer strides. It also requires hip mobility, flexibility, and glute engagement to pull your leg back behind you. Though it was in vogue in the 1970s to try to maximize stride length by throwing your legs as far in front of you as possible, that’s now considered overstriding, which can lead to injuries and is not efficient. Mostly, though, an individual’s stride length can only be increased so much.
Studies done on 100-meter sprinters, who have the longest stride length of any racers, show that over a range of athletes the average length is consistently 1.35 times the runner’s height. In distance running, strides are understandably shorter than in sprints.
The best thing a casual runner can do, rather than worry about stride length, said Daniels and Chumanov, is to focus on increasing their stride rate.
First, count your steps while running. Count how many times your right foot lands in a 30-second period and then multiply by four to get your total stride rate per minute. Then, attempt to increase that rate slightly. It’s easiest to play with your stride rate on a treadmill where you can set the speed to stay the same, said Daniels. You can also purchase a metronome and use it for brief periods during runs to build up your cadence.
However, UK coach and sports rehab specialist James Dunne cautions runners not to become too focused on some so-called magic number for stride rate. Instead, he suggests simple small increases at a time.
“Unnaturally forcing an uncomfortably high cadence too soon can result in its own technique issues,” said Dunne.
Check out our other Social Media sites:
The u-VIB team.
Contact our Team at u-VIB
source: The Competitor by Kelly O’Mara