Runners are a busy bunch. Too often, we push back our speed, fitness or weight-loss goals when life gets in the way. The focused workouts over the following pages are designed to make you faster, stronger and fitter - in however many minutes you can spare.The busy runner's guide ...

"Regularly incorporating tempo runs into your training will increase your aerobic capacity, allowing you to run at a faster pace for longer," says Karp. And when fatigue sets in, "you'll have the reserves   to power through it".Here's how Run at 30 seconds per mile slower

-founder of the Furman Institute of Running and Scientific Training in South Carolina, US. But that can increase your risk of injury. "To stay healthy, target areas of fitness you normally don't pay attention to - like flexibility and strength," says Pierce. During

. But these multitasking workouts also stress your body, so follow up with a day of easy running, cross-training or a rest day. Here's how to get it together.Run + StrengthBeat fatigue"Sandwiching a lower-body strength workout between two easy runs simulates race