Long, slow treadmills workouts are effective for creating beginner workouts that help you build stamina and endurance while you burn calories. Fast, short workouts raise your calorie burn per minute and help increase your cardiorespiratory capacity or ability to work at a higher heart rate. Including intervals during steady-state treadmill routines helps you get the best of both exercise intensities.
Long, Slow Workouts
Exercising for long periods at moderate heart rates improves your ability to use your muscles, including your heart and lungs, for longer periods. This will help you work out longer once you’ve built cardio stamina, or your ability to challenge your heart and lungs for extended periods. Longer, less-intense treadmill workouts burn more fat as a percentage of your total calories burned, but that doesn’t mean you burn more fat with these so-called “fat-burning” workouts. Your total calorie burn will be lower during low-intensity workouts, so your total fat loss will be less than if you exercised at a higher heart rate.
Fast, Short Workouts
A high-intensity workout burns more calories per minute than a less-intense workout. For example, a 125-pound woman will burn 240 calories per hour speed walking at 3.5 mph, according to the Harvard School of Public Health. Raising her speed to a 5 mph run, she’ll double her calorie burn. Despite the fact that more of her calories burned will come from glycogen, her total calorie burn, including fat calories, will be higher. This is all dependent on how long you run -- a slow, one-hour workout will burn more calories than a fast, 10-minute workout.
Low-intensity treadmill workouts usually mean walking, which keeps one foot on the tread at all times, making this a low-impact exercise choice. Running requires you to leave the ground with both feet at the same time, creating a high-impact workout that can be stressful on your ankles, knees, hips and lower back.
Your best bet for a slimming workout might be to combine steady-state walking or jogging that doesn’t fatigue you to failure with short, high-intensity intervals that elevate your heart rate and calorie burn. For example, after warming up with a walk for two minutes, begin using the treadmill at a heart rate that causes you to breathe hard, but will let you keep exercising for 30 minutes or more without stopping. Every five minutes, add 60 seconds of fast running, followed by two to three minutes of a slower recovery pace. As you build cardio strength and the ability to recover from sprints, add more frequent intervals and decrease your recovery times. Check with a health professional before adding this type of exercise to your treadmill routines.
Long, slow treadmill workouts allow you to add upper-body exercises that a short, fast run might not. For example, during a walk or moderate-intensity jog, you’ll be able to maintain your balance as you perform a variety of dumbbell exercises. You might not be able to do this effectively while running. Another way to add resistance to your treadmill workouts is to increase the incline while you walk or run. This is effective during both slow and fast workouts.
Sam Ashe-Edmunds has been writing and lecturing for decades. He has worked in the corporate and nonprofit arenas as a C-Suite executive, serving on several nonprofit boards. He is an internationally traveled sport science writer and lecturer. He has been published in print publications such as Entrepreneur, Tennis, SI for Kids, Chicago Tribune, Sacramento Bee, and on websites such Smart-Healthy-Living.net, SmartyCents and Youthletic. Edmunds has a bachelor's degree in journalism.