You got home from work late. You were going to run for 45 minutes, but now you've only got 10 minutes before your best friend picks you up for dinner.
It's 11:50 am. You're in a hotel room. Checkout time is noon. It sure would be nice to have done some kind of workout before you head to the airport for a long flight home.
You've only got 10 minutes. What can you do?
First of all, you should do something. A lot of runners assume 10 minutes is not enough time to do anything that will make a difference to their running, but that's not true. You can burn anywhere from 100 to 200 calories in 10 minutes of running. Do that 20 times a year instead of taking a day off because you "don't have enough time" and you'll prevent a pound of weight gain — or lose a pound.
Also, runners underestimate the degree to which every step they take counts as stride practice. Runners put too much stock in the metabolic element of running fitness and not enough in the neuromuscular aspect. A 10-minute run might not be long enough to stress your metabolic system and stimulate fitness improvement in that way, but it's enough time to complete about 1,500 practice steps, which will help to refine your running coordination — and more than half of long-term improvements in running performance come from such refinements.
Finally, you can't underestimate the mental benefits of 10 minutes of exercise. If you do that instead of nothing you will get a nice mood boost, ameliorate a bit of that cabin-fever feeling, and assuage some of the guilt of not exercising at all.
Okay, you're convinced. You should do something. But what is the best possible use of 10 minutes for the runner? Without taking away from the value of 10 minutes of slow or fast running, I will argue that the best way to allocate 10 minutes is to perform a short plyometrics workout.
Plyometrics, or jumping exercise, is something that every runner should do and that most runners don't do. Running is a form of jumping. Plyometrics isolates and exaggerates the jumping element in running and thereby improves running performance in a way that running itself does not. This is a proven fact. One study found that runners who replaced one-third of their normal running with plyometrics improved their race times, while runners who continued with their normal running schedule did not.
You might think that plyos improve running performance by increasing muscle power in the legs, but that appears not to be the case. Instead, plyos improve running performance by enhancing leg stiffness during running. The legs function as springs when you run. Each time a foot lands, the body sends impact forces into the ground; these forces then rebound back into the foot, propelling forward motion. About half of the energy required for running comes to us "free" from these physics. But not all of the energy that enters the ground comes back into the foot and is used for propulsion. A certain amount dissipates. The relative stiffness of the legs is one major factor that determine how much of the available free energy is captured and used. A runner who has nice, tight joints and is able to tense the right muscles to the right degree at the right time creates a stiffer spring that captures more energy. Plyometrics enhances this ability.
The great thing about plyos for runners is that it doesn't take much to make a difference. Whereas 10 minutes is inarguably shorter than the ideal amount of time for any type of run, it's plenty of time for a full plyometrics session. Here's one:
10-Minute Plyometrics Workout
Warm up with 3 minutes of walking lunges, deep squats, and jumping jacks to prepare your legs for maximal-effort jumping.
Jump as high as you can off both feet. Repeat 20 times.
Rest one minute.
Assume a split stance (one foot a half-step ahead of the other), bend down, and jump as high as you can. In midair, reverse the positions of your legs and land in the new stance. Continue jumping and alternating your leg positions until you've competed 20 total jumps.
Rest one minute.
Stand on your right foot with your left knee bent and your left foot elevated. Bend down and jump as high as you can. Land on the same foot. Complete 10 total jumps and then do 10 more off the left foot.
Sign up for your next race.