Stride length vs stride frequency: which makes you faster?

Speed = stride length × stride frequency

Running speed in meters per second is the length of each step in meters multiplied by the number of steps you take each second. A sprinter taking 2.2m steps at 4.5 steps per second is moving at 9.9 m/s. Lengthen the steps to 2.3m at the same rate and the speed rises to 10.35 m/s.

Coaches and research papers often say "stride" when they mean one step, from one foot landing to the other foot landing. In a gait lab a stride is two steps. Every number on this page is per step, which is how sprint analyses report it.

The two numbers pull against each other. In a study of 36 athletes sprinting at the 16m mark, those with longer steps tended to have lower step rates, and the reverse. The biggest source of that trade-off was how much upward velocity the athlete took off with. Bounding higher buys a longer step and spends time in the air, so the next step comes later.

What were Bolt's stride length and frequency?

Researchers counted Bolt's steps frame by frame from TV footage of the Berlin 2009 final and compared them with the rest of the field. The paper labels each step a stride.

Bolt's step rate was 0.30 per second below the field's average. His steps were about 24cm longer, which more than covered the gap. The same analysis split the race into 20m sections:

Step length grew in every section, for Bolt and for the field's average. Frequency peaked between 20 and 40m and fell over the last 20m, so the late-race slowdown showed up as fewer steps per second while the steps kept getting longer. For Bolt's splits and top speed, see Usain Bolt's top speed.

Does height decide your stride?

It shifts the balance. Leg length is one of the sources of the length-versus-rate trade-off identified in the 36-athlete study, and Bolt, at 196cm, ran the Berlin final with longer steps and a lower rate than the field's average. A study of 11 elite sprinters over 52 races found that some athletes ran faster mainly by lengthening their steps and others mainly by quickening them, and called the pattern highly individual.

Copying someone else's numbers rarely works. A review of elite sprint training warns that an athlete who tries to take a world-class sprinter's step length will likely run slower, because the ground force tilts more vertical, so the useful comparison is with your own numbers from last month.

Work out yours from video

Researchers get these numbers from race footage, and you can do the same on a phone. Set two cones 20m apart with a 20m run-in before the first, the same flying 20m used for top-speed work in our sessions. Film from the side, level with the middle of the zone and far enough back to see both cones. Slow motion helps.

• Count the foot contacts between the cones, to the nearest half step.
• Time the zone from the video. Count the frames between your torso crossing the first cone and the second, then divide by the frame rate (240 frames at 120 fps is 2.0 s).
• Step length = 20m ÷ steps. Step frequency = steps ÷ time. Speed = 20m ÷ time.

Say you count 9.5 steps and the zone takes 2.40 s:

Run the same test every few weeks from the same camera spot. When your time drops, the step count tells you which half of the formula moved. To estimate your top speed from a 40-yard or 100m time, try the speed calculator.

How to increase stride frequency

You don't raise your rate by swinging your legs faster through the air. When researchers tested 33 runners with top speeds from 6.2 to 11.1 m/s, the time to swing the leg into position for the next step did not differ with speed. The fastest runners pushed on the ground about 1.26 times harder. With swing time fixed, more steps per second come from shorter ground contacts, and short contacts need high force delivered fast.

• Sprint fast and often. Flying 20s (4 × 20m with a 20m run-in at 100%, 5 min rest) put you at top speed where contacts are shortest. Sprint workouts has the full session.
• Do plyometrics for stiffness. The elite training review recommends focusing on short ground contacts in jumping work. Pogo hops and hurdle hops are in plyometrics for sprinters.
• Run mini-hurdles at short spacing. Ten collegiate sprinters ran three times over 10 mini-hurdles, 22cm high and 90cm apart, and in a 60m sprint afterward their top speed rose 3.2% and their peak step rate 3.3%. That was a same-day effect, so use it as a primer before sprints. Wicket runs cover the full-stride version.

How to lengthen your stride

A longer step at top speed comes from putting more force into the ground during the contact. Reaching the foot out in front adds length on paper and braking on the track, which is the subject of the overstriding guide. Bounding upward lengthens the step too, at the cost of rate, as the 36-athlete study showed.

Strength work carries over: a meta-analysis found that gains in lower-body strength transfer to sprint performance. Resisted sprints help too. In a study of nationally ranked youth sprinters, a resisted-sprint session lengthened their steps by 0.09m in the sprints that followed it over the next two days. The acceleration drills guide gives the sled loads and reps to use.

Reaching for longer steps

The foot lands further ahead and brakes you. Push harder behind you and let length follow.

Pitter-patter turnover

Choppy steps trade length for rate. Your speed only rises if each contact still pushes hard into the track.

Chasing an elite athlete's numbers

Your leg length and strength set your mix. Track your own step count and time instead.

The positions that make both numbers possible are in sprint form.