If you want to run fast, the saying goes, you’ve got to run fast. To stoke speed, most runners do traditional speedwork: aiming for near race pace over distances of 400m or more, with recovery periods equal to the length of the repeat (or slightly less). A way to get fast even faster is with super-short, super-fast efforts, which is sometimes referred to as high-intensity interval training (HIIT).
While HIIT definitions vary, repeats are generally 10-60 seconds long, run nearly all-out, and are followed by a rest period lasting one to four times the length of the effort (so you’re recovered to do the next repeat at the same speed and with good form). Researchers have found the low-volume, high-intensity approach of HIIT can boost speed and fitness.
‘For the athlete who’s already doing intervals, upping the intensity with short bursts of speed may provide new benefits,’ says Dr Martin Gibala, a researcher at McMaster University, Canada. Your cardiovascular system gets stronger and pushes more oxygen through your body. Muscles get better at using oxygenated blood, and your stride becomes more efficient as coordination between the muscles and your nervous system improves. The benefits may even extend to reducing your risk of chronic diseases by improving blood sugar control.
Running super-fast does increase your risk of injury, however. You need to be strong and flexible and have a solid base of both mileage and speedwork to do this training safely, says Joe McConkey, an exercise physiologist and coach at the Boston Running Centre. You’re ready for HIIT workouts if you’ve been running four to five times a week for at least four months, regularly doing some runs at 60-90 seconds per mile faster than easy pace, and completing a weekly long run of at least 50 minutes (not you? See Start Speeding, right). Start with one HIIT session a week, and build up to no more than two in a 10-day period.
On the hills
Inclines are a great venue for super-fast speedwork. Compared with a flat surface, hills reduce the impact on your legs and limit your range of motion, thereby lowering the risk of strains and pulls. Plus, hill repeats build muscle power, which helps you run more efficiently on level ground, says McConkey.
On an incline, start with 3x30-second moderate repeats and walk down the hill for recovery. When this becomes comfortable, progress to 4x1-minute near all-out efforts with a downhill jog and an additional 30-60 seconds’ jogging or walking. Over time, add extra reps, extend the effort length up to two minutes, and aim for steeper hills, says McConkey.
On the trail
Running fast over softer, less-groomed terrain such as bridleways, trails or grass can boost your agility and athleticism – or your ability to run with the ‘precise amount of power, speed and coordination for efficient movement’, says McConkey.
Because of the terrain and potential strain on your legs, ease into offroad sessions. Do 5x30-second accelerations at a moderate intensity during an easy 20-minute run, and build up to 10x60-second near-all-out bursts during a 40-minute run. From there, progress to running five cycles alternating 30 seconds of all-out running with 90 seconds’ jogging, then to 10 cycles alternating one minute easy with one minute super-
hard. Be careful not to trip!
On the track
High-intensity track sessions move the muscles through the full range of motion, improving elasticity and enhancing coordination between your nervous system and your muscles. With time, you’ll develop a more efficient stride at all your paces, says McConkey.
Begin with two 100m accelerations that include 40m at top speed, with two to three minutes of walking or jogging between. Build to 6x150m hard, including 80m at top speed, with three to four minutes’ jogging or walking rest. Over time, increase the number of repeats to 10, lengthen reps to 300m (running nearly the entire distance at top speed), or reduce the rest interval to one minute.