It's that time of year when I take my running workouts inside to the treadmill. Or should I say dreadmill? The treadmill can be a real drag, but I find that using a plan to guide my workout keeps me on track, interested, and motivated, so the time flies by. Here are three of my favorite (read: not boring) treadmill workouts.

Walk-Jog-SprintThis is one of my go-to workouts when I'm dreading my time on the treadmill. It keeps me guessing for a solid 45 minutes, so it's over before I know it! And I feel like I've really worked hard when I'm done. I'm almost always a sweaty mess at the end!

Walk at 4.0 at 7.5 incline for 4 minutesJog at 6.5 at 1.0 incline for 5 minutesRepeat walk and jog twiceJog at 6.5 at 2.0 incline for 3 minutesRun at 7.0 at 1.0 incline for 3 minutesSprint at 8.0 at 1.0 incline for 1 minuteJog at 6.0 at 1.0 incline for 1 minuteSprint at 8.0 at 1.0 incline for 1 minuteRun at 7.0 at 1.0 incline for 1 minuteJog at 6.5 at 1.0 incline for 3 minutesCool down (walk) for 5 minutes

Total time: 45 minutes

Roll PlayChanging my speed every two minutes keeps my interest and motivation high while running on the treadmill. I covered a little over 5.5 miles in 60 minutes during this workout. There's a walking interval from minutes 30 to 35, so this workout can easily be shortened to 35 minutes if needed.

Incline: 1.0

Minutes 0 to 5: 4.2 mph5 to 7: 6.3 mph7 to 9: 6.5 mph9 to 11: 6.7 mph11 to 13: 6.5 mph13 to 15: 6.3 mph15 to 20: 4.5 mph20 to 22: 6.4 mph22 to 24: 6.6 mph24 to 26: 6.8 mph26 to 28: 6.6 mph28 to 30: 6.4 mph30 to 35: 4.4 mph35 to 37: 6.5 mph37 to 39: 6.7 mph39 to 41: 6.9 mph41 to 43: 6.7 mph43 to 45: 6.5 mph45 to 50: 4.2 mph50 to 51: 7.0 mph51 to 52: 6.9 mph52 to 53: 6.8 mph53 to 54: 6.7 mph54 to 55: 6.6 mph55 to 60: 4.2 mph

Total time: 60 minutes

Three-Mile ChallengeWhen I'm short on time, I like to challenge myself to run three miles as fast as I can. I love a challenge, so trying to beat my previous mile gets me excited about my workout. If you're not into running, a three-mile power-walking challenge also will work!

Warm up for 10 minutes (walk or slow jog)Run one mileRecovery: two-minute walkRun second mile. Try to improve your time from mile the first mile.Recovery: two-minute walkRun third mile. Try to improve your time from the previous two miles.5 minute cool down (walk or slow jog)