Sprint training, started on one word

What counts as a speed workout?

Anything short and fast enough that speed and form, not endurance, set the limit: strides, 100 or 200 m sprints, hill sprints, ten-second bursts, the kick at the end of a race. In Gears it's all your Hard gear, and Hard is personal: a quick jog for a new runner, a fast sprint for an experienced one. Speed work is a small, sharp part of the week, laid on a base of easy running, not a replacement for it.

Why are sprint workouts hard to do well on your own?

Because the details slip when nobody's calling them.

• The start is messy. You glance at a watch, wait for a beep and lose the first second of every rep.
• The first rep is too hard. The rest get slower and the session turns into survival.
• Recoveries get cut short. Speed needs fresh legs. Rush the rest and it becomes endurance work.
• It lands on the wrong days. Speed on tired legs is slow, and it costs the next run too.

How does Gears coach sprints?

It builds you up, counts you in and starts each rep on the word.

1. Built up, counted in, started on the word

Before a Hard block in a plan run, the coach builds you up (“Here it comes. Breathe now, not then.”), counts you in, and starts short sprints on one exact word, “Go.”, on the beat. The last ten seconds get their own call, and the watch clicks through the final three. More on the voice coach.

2. Sprints by time or distance

Build a session in the run editor from Walk, Easy, Steady and Hard blocks, by time or distance, with an optional pace target on each, and repeat a pair with one tap: 5 × 400 m takes nine taps. The interval workouts in Find a run add training targets for Top speed, Anaerobic capacity and Finishing speed (“Running faster when you are already tired.”), each with its own runs.

3. Bursts and short sessions

Bursts are ten seconds of Steady or Hard dropped into easy and long runs, “played as fun rather than work”. Lucky Dip is “An easy run with ten-second sprints at moments you cannot guess.” The quick runs under ten minutes include Tabata 9, the One-Minute Workout, Mini 10-20-30 and Up the Gears 9. More on your personal gears.

Racing? The Sit and kick strategy in race mode is “Just under your pace until the last tenth, then everything.”

What does a sprint session sound like?

How does speed work fit into a running week?

As the smallest part of it. With Gears Plus, the plan holds at most two hard runs a week, never back to back, and Today's gear moves a hard session off a morning your body isn't ready for it. Seven minutes is a real workout, so speed fits a short day, and the rest of the week stays Easy.

Speed needs warm legs. The run editor has warm-up and cool-down options; with the coach on Talkative, it walks you through the warm-up: settling in, breathing, shoulders, posture, feet and cadence, then an effort check before the work.

Can I do sprint workouts with just my iPhone?

Yes. The iPhone runs the whole session with its own GPS, step counter and barometer, and coaches by pace when there's no heart rate. With an Apple Watch you can leave the phone behind and keep the haptics on your wrist. More on the Apple Watch running app.

What Gears doesn't do

• It doesn't time you to the hundredth or measure your top speed. It coaches the effort.
• It doesn't coach running power or sprint mechanics from sensors. Form reminders are general and come on a timer.
• It doesn't switch off safety. At every toughness setting, a very high heart rate gets “Heart rate's very high. Ease off now.”
• It isn't medical clearance for maximal effort. Read the health disclaimer.

Read next: What's a good running cadence? and How to run hills.