Great new article from Active.com about the calorie burning/weight loss effects of tempo runs and sprints

Check out said article hither. Or read the cut and paste job thither.

How to Burn More Calories on Your Run

Liz Plosser • Women's Health

Most people operate under the assumption that the more they run, the more weight they'll lose. That's true, but only to a point. Running is an incredibly effective and efficient form of exercise for burning calories. (You burn about 8.5 calories a minute when moving at a comfortable pace.)
Problem is, the more miles you log, the more efficient your body becomes at running and the fewer calories it burns, says Wayne Westcott, Ph.D., fitness research director at Quincy College in Massachusetts.
In other words, you'll initially drop some pounds, but your progress will flatline as soon as your body adjusts to your exercise regimen. Plus, running long distances on a regular basis takes a physical toll (in the form of injuries, like runner's knee) and can seriously dampen your enthusiasm. Ultimately, all that pain and boredom can cause many people to burn out and give up.
Thankfully, there is a better (and easier) way. By learning how to make your runs more efficient at burning fat (by running with more intensity and by making your body stronger), you can get more benefits in less time, says Andrew Kastor, a running coach in Mammoth Lakes, California.
You'll still need to run three to five days a week (depending on which of the two programs you decide to follow), but rarely for more than 20 minutes a pop. That's not so bad, right?

Sneak in Some Speed

If you work out, you've probably heard of intervals—short bursts of intense exercise with periods of recovery in between. Here's why they work: When you chug along at a comfortable pace (as most people do), your body gets energy easily from the oxygen you inhale. But once you switch into high gear, your muscles start working harder to process that O2, so they expend extra energy recruiting other chemicals in the body (adenosine-triphosphate and phosphocreatine, in case you're interested) to get the job done.
"Your body likes to be on cruise control, because that's where it's most gas efficient," explains Westcott. "But when you push on the gas pedal, as you do in intervals, your body becomes less efficient and has to burn more calories to do the activity."
And these quick-but-killer efforts may be the closest thing you'll find to a magic calorie-burning bullet. You not only log less sweat time (which is kinder to your body) but also continue to incinerate calories at an increased rate even during the walking or jogging recovery periods, says Westcott.
The body-slimming benefits of intervals don't end there. Your metabolism logs serious OT after your run too. In a study in Medicine & Science in Sports & Exercise, women who ran hard for two minutes followed by three minutes at a low intensity torched more calories in the 24 hours following their sweat sessions than those who did slow, steady mileage.
They also lost 4 percent of their body fat in the weeks that followed, while the continuous-pace group didn't lose any. That might not sound like a huge number, but "it's enough to see a noticeable change in the mirror," says lead study author Craig Broeder, Ph.D., an exercise consultant in Naperville, Illinois.
Intervals come in a variety of sizes, and you can count on the fat-melting effects no matter how long an interval you do. "It's best to mix and match short, medium, and long intervals to keep your body guessing," says Westcott.Devote one day a week to one of the calorie-crushing regimens below, says Kastor. Warm up and cool down with five to 10 minutes of slow jogging or fast walking. For the most slimming results, switch up your workout—don't just stick with the interval routine that feels easiest.

Quickies

Find a flat section of road, or hit the track or treadmill, and speed up to a hard but sustainable effort (really huffing and puffing) for 15 seconds. Jog or walk to recover for 60 seconds. Repeat six times.
Beginner: Build up to 10 intervals over eight weeks.
Seasoned runner: Build up to 12.

Short Repeats

Find a flat section of road, or hit the track or treadmill, and speed up to a hard but sustainable effort for 30 seconds. Jog or walk to recover for 60 seconds. Repeat four times.
Beginner: Build up to 10 intervals over eight weeks.
Seasoned runner: Build up to 12.

Long Repeats

Beginner: Run a quarter of a mile (equal to one loop of a track) on flat or rolling terrain at a hard but sustainable effort, and recover by jogging or walking for two minutes. Repeat four times, building up to eight.
Seasoned runner: Change the distance to half a mile (two loops of a track).

Toned and Tranquil

To mellow out, you may want to lace up your running sneaks. According to research in the British Journal of Sports Medicine, running—and other forms of endurance exercise, including cycling—ups the concentration of calming compounds called endocannabinoids in your brain, inducing that blissful postexercise calm. And the reverse is true too: A mellow mind can lead to a fitter body. "When you're stressed, your muscles are more tense. Because they're working to hold that tension, they're less able to do their job in terms of your workout," says Jason Karp, Ph.D., a spokesperson for the American Council on Exercise. "If your mind is calm—but alert enough to focus—you'll get more out of your routine."

Head for the Hills

Like many things that are good for you, hills aren't particularly appetizing. But the extra effort it takes to trudge up them is worth it: For each degree of incline, count on at least a 10 percent increase in calories burned, according to Jana Klauer, M.D., a nutrition and metabolism expert and research fellow at St. Luke's-Roosevelt Hospital in New York City. So running up a 5 percent grade (a gentle hill) will burn 50 percent more calories than running on a totally flat surface for the same amount of time.
"You work harder when going uphill because you're moving forward and up at the same time," says Marcus Kilpatrick, Ph.D., an associate professor of exercise physiology at the University of South Florida in Tampa. Plus, hills recruit more muscles than flats do. The end result is increased calorie burn, a leaner body, and a perkier butt. Kastor recommends doing the following hill workout once a week:
Find a gentle hill or set your treadmill to a 5 percent incline.
Run up the hill at a hard but sustainable effort for 10 seconds. Jog or walk back to where you started, or reset the incline to zero, until you completely catch your breath (it should take about 45 to 60 seconds).
Beginner: Repeat four to eight times.
Seasoned runner: Repeat six to 10 times.

Strengthen Your Stride

If they gave best supporting actress awards for weight loss, strength training would take home the trophy every time. Think about it this way: Strength training makes you stronger from head to toe, so you can run harder every time you pound the pavement. A review of studies in The Journal of Strength and Conditioning Research found that runners who did resistance-training exercises two or three days a week, in addition to their weekly cardio regimens, increased their leg strength and enhanced their endurance—two things that contribute to weight loss.
And resistance exercise helps keep you injury-free, so you're not stuck on the couch when you could be incinerating calories on a run. A recent study in the journal Clinical Biomechanics found that female runners who did six weeks of lower-body exercises, like the ones that follow, improved their leg strength, particularly in the hips—a common source of pain and injury for runners.
If your schedule allows it, try lifting before you run to increase fat burning while you run. "Resistance training is mostly a carb-burning activity," explains Westcott. "After about 20 minutes of strength training, you deplete your glycogen stores (carbs) so fat is readily available to burn."
And even if you don't follow strength training with a run, you still get an after burn.
"You elevate your metabolism by 25 percent for the 60 minutes following resistance exercise," says Westcott. So if you burn 200 calories in a 20-minute strength session, count on sizzling an additional 50 calories after your last rep. This total-body strength workout designed by Kate Moran, a trainer at Equinox gym in Chicago, takes no more than 20 minutes and complements the running plans above. "Working the glutes, hamstrings, and core will help you prevent injury and become stronger so that you get more out of your runs," says Moran.
Do three sets of 12 to 15 reps (unless otherwise noted) twice a week; rest for 30 seconds between sets. All you'll need to complete the routine is a pair of five- to 10-pound dumbbells and a resistance band.
Unilateral lift Grab a dumbbell in each hand, stand on one leg (keep it as straight as possible), and lift the other leg slightly off the floor. With your raised foot stationary, lean forward with your arms straight and extended toward the floor as you bend at the hips (not the knees) and keep your back flat. Return to start without lowering your raised foot.
Lateral-band walk: Place a resistance band around your ankles. Stand with your feet hip-width apart, then step to the side with one foot, keeping your toes facing forward. Bring your feet back together; repeat. Walk 15 steps in one direction, and then 15 steps back, leading with the opposite foot. That's one set. Repeat three times.
Marching hip raise: Lie on your back with your knees bent and feet flat on the floor. Raise your hips to create a straight line from your knees to your shoulders. Lift one knee to your chest, trying not to drop your hips. Lower, then lift your other knee to your chest. That's one rep.
Leg raise: Lie on your back with your arms by your sides, palms up. Keeping your legs straight, raise them until they are perpendicular to the floor. Slowly bring them back to the starting position, keeping your lower back against the floor.

Go Long (in Moderation)

The good news is that you don't need to log more than one long run a week to get the max calorie-burning benefit, and a long run means 30 minutes or more. This sustained effort will improve your endurance by increasing your heart's capacity and strengthening ligaments and tendons, so you feel stronger during your short runs, says Kastor, who created the "Run Off the Weight" training plans, above. "And the more effort you can put into each workout, the more calories you'll burn."