Phil Campbell, MS, wants you to run fast — really fast, like you did when you were a child. “How many kids say, ‘Hey, I think I’m going to go out and jog at a 10-minute-mile pace?” asks the Jackson, Tenn.–based speed coach. “I’ll tell you: zero. When kids go out to play, they run, sprint, laugh, chase, zigzag, climb, sweat and get totally exhausted.”
Kids have the right idea, says Campbell, with all their enthusiastic zipping around, and the pleasure they take in feeling fully alive and aware of their own bodies. Not enough moms, dads and other grownups move that fast, he notes, and as a result, they rarely achieve optimal fitness.
A growing body of research suggests that most adults could benefit by emphasizing speed workouts more often. The benefits extend far beyond our cardiovascular system and muscles — to our biochemistry and even our brain. Here are five great reasons to go fast on a regular basis:
1. Speed changes your hormones.
Recent research points to the body’s ability to produce human growth hormone (HGH) through exercise — and while HGH doesn’t appear to directly improve strength or exercise capacity, it’s very good at metabolizing fat.
Campbell cites a 2005 study by University of Bath (England) researcher Keith Stokes, widely considered the foremost expert on HGH and exercise, that described how a series of 30-second sprints sharply increased HGH in the body while exercising — and also for roughly two hours after a workout. Says Campbell: “Once the exercise-induced HGH is released, it will target body fat like a heat-seeking missile.”
Campbell, author of Ready, Set, Go! Synergy Fitness for Time-Crunched Adults, outlines four benchmarks he says are necessary for exercise to produce HGH at fat-blasting levels: 1) oxygen debt or feeling out of breath; 2) muscle burn (the sensation caused by lactic acid overload); 3) an increase in body temperature by at least one degree (characterized by a moderate sweat); and 4) adrenal response (feeling out of breath and “slightly” in pain).
This sprint-training approach (which also can be performed on a stationary cycle) can be extremely challenging, but the results can be dramatic: Campbell says his clients routinely report weight loss of up to 20 pounds in eight weeks.
2. Speed gets you fitter, faster.
The fitness gains promised by interval training sometimes sound too good to be true. And, indeed, this sort of sprint-focused workout is only one part of a well-balanced fitness program. But it’s an important part, particularly if you want quick results.
Consider recent studies published in the Journal of Applied Physiology and Journal of Physiology, conducted by the Exercise Metabolism Research Group at McMaster University in Hamilton, Ontario. Researchers there found that a total of two to three minutes of sprinting, done in 30-second bursts during a 20-minute workout three times a week, produced the same results as three endurance cycling sessions per week, each of which lasted 90 to 120 minutes. In other words, just one hour of interval training produced what would otherwise take up to six hours of steady-state exercise to accomplish.
Plus, after just two weeks, or six workouts, tests indicated that these subjects increased their endurance on average by 100 percent, and their muscles began using oxygen more efficiently to burn fuels. Lead researcher Martin J. Gibala, PhD, says rapid-fire results can apply to beginners and elite athletes alike, but he cautions that any decision to go all-out requires medical clearance and a baseline of fitness. (For more on speed training, see “Fast Forward”.)
3. Adding speed to your workout burns more fat calories – including fat calories.
The fat-burning benefits of low-intensity exercise get lots of publicity, but it turns out that sprint- and speed-oriented workouts may actually deliver as good or even better weight-loss results.
Here’s why: It’s true that working at a lower intensity is easier to ma intain for longer workouts (an hour or more) and that it allows you to burn a greater percentage of fat calories (as opposed to calories derived from carbohydrate or glycogen stores). But minute for minute, this lower level of exertion burns substantially fewer total calories, and thus fewer fat calories overall. (For more on the subject, see “A Better Way to Burn Fat”.)
Research indicates that adding interval training and other high-intensity exercise to your fitness regimen also conditions your body to burn more fat during moderate-intensity exercise.
According to a 2006 study at the University of Guelph in Ontario, just two weeks of interval training (60-minute sessions on a stationary bike, with 10 four-minute intervals and two minutes of recovery between intervals) increased the amount of fat subjects burned in an hour of moderate cycling by 36 percent.
Jason Talanian, PhD, a physiology researcher at the University of Guelph, suggests that the increased fat-burning capacity during moderate exercise occurs because the high-intensity work produces more mitochondria (your body’s cellular powerhouses). “You are basically increasing the machinery in your muscles,” he explains.
Plus, high-intensity exercise recruits more fast-twitch muscle fibers, compared with the slow-twitch fibers called upon during slow, steady workouts (see also “The Fast and Slow of It”). And fast-twitch muscles increase HGH.
Talanian suggests adding a weekly interval routine to the end of your usual workout. If you generally run for, say, 45 minutes, use the last 15 minutes to run 30- to 60-second bursts (intervals) followed by a few minutes of slow jogging (or even walking) to recover.
Start with three bursts and progress to six. Or, if you’re totally new to sprinting, start with just one burst of speed toward the end of your workout, and gradually build in more sprints over time.
4. Speed might make you smarter.
While researchers have long made a case for exercise’s positive influence on brain function, most of the studies have evaluated individuals following a low-intensity aerobic program, such as walking or steady-state indoor cycling. Campbell and others believe a high-intensity workout can achieve better results.
“I think it is because your body produces more dopamine and serotonin [brain neurotransmitters] by going harder,” he explains. “I hear this all the time: People who do the eight sprints in my workouts almost always say the fifth one is the toughest. I think it is because after that, they release so much dopamine and serotonin that the sixth, seventh and eighth sprints are easier because you don’t feel as stressed.”
Some research suggests that such high-intensity training can increase the amount of catecholamines in the brain as well as in the body. Catecholamines, neurotransmitters found in the amino acid tyrosine, help the brain to stay sharp during prolonged work, sleep deprivation and other stressful situations. Associated with improved cognitive function in basic biology research, the catecholamine dopamine, for example, is a brain chemical needed for learning, motivation and motor skills.
“One of the best results of high-intensity training is you don’t feel lethargic after lunch anymore,” says Campbell. “Now that’s a perfect complement between the brain and body.”
5. Speed puts spring in your step.
What’s missing from most workout routines — and from adult lives in general — is a keen sense of vitality, says Mehmet Oz, MD, coauthor of the bestselling You: Staying Young.
“We need to be bouncy,” says Oz. “You want your life to be like a kid, bouncing around. We start to lose that in our 20s and 30s.”
Oz suggests even a 30-second burst per day will create new confidence and an appreciation for what he calls the “spectacular engine” that is our body.
“Exhaust your muscles completely once a week,” he suggests. “Your body is supposed to have its engine revved every once in a while.”
Pick Up the Pace
Speed workouts don’t have to become another obligatory notch in your fitness belt. “Just cutting loose — or getting bouncy — gets to the spirit of adding speed for vitality,” says Mehmet Oz, MD, coauthor of You: Staying Young. Here’s a starter kit of fast-breaking ideas:
- Play tag with kids — preferably quick little rascals. Set up the boundaries to allow for 5- to 15-yard dashes. Require everybody to keep moving or they become “it.” Run after kids even if you can’t catch them. They love it, and your fat-burning cells will, too.
- Chase the dog. Or toss the ball and then race your canine friend to “fetch” it.
- Break out the kickball or dodgeballs.
- Take a group cycling class. The right class will do more sprinting than slow climbing.
- Kickbox. Start with at least three classes to get the hang of it. Then practice on your own. Remember: You never actually have to fight anyone.
- During your swim workouts, pretend every eight to 10 minutes that you are racing Michael Phelps or Natalie Coughlin at this past summer’s Beijing Olympics. Go as hard as you can for a length. Build up to a full, hard lap. Be sure to swim at recovery pace between imaginary races.
- Jump in place for 30 seconds. Stay on the balls of your feet. Go as fast as possible without losing your balance.
- On bike rides, pick a stretch of road or path that allows you to cycle full-force for 45 seconds to a minute without any danger. Mark that stretch mentally and do it every ride.
- Run your own personal 40-yard dash, stopwatch and all. See how much you can improve over time.
- When you take the stairs at home or at work, go at a full run. Gradually build up the number of flights you can do at top speed.
This article originally appeared as “The Need for Speed” in the September 2008 issue of Experience Life.