ASU Research E-Magazine: Strength in Numbers

So you want to start a serious exercise program. How do you weed through all the conflicting advice and find the best workout program to follow? The good news is you don’t have to. ASU’s Matthew Rhea has done the work for you.

Pick up a handful of health and fitness magazines and you’ll find dozens of articles describing the latest exercise research. Unfortunately, some of these stories will probably contradict one another.

One headline might proclaim that you only need to perform one set of exercises to build strength. Another will say that three to four sets are ideal.

Then there’s the issue of how much weight to lift. Should you do just a few repetitions of a heavy weight, or lots of reps with a lower weight? How many days per week should you exercise?

With so much confusing information, it’s a wonder people manage to get through a workout at all. So how are you supposed to weed through all this conflicting advice and find the best workout program to follow?

The good news is you don’t have to. Matthew Rhea has done the work for you. Rhea is a doctoral student in exercise and wellness at ASU East. He also works at the ASU East fitness center, designing workouts for student athletes and local firefighters.

Frustrated with the conflicting research on strength training, he wanted some solid numbers to back up his training programs. Rhea conducted a meta-analysis of 140 different studies to determine the ideal weight training “prescription.” A meta-analysis is a statistical method for analyzing the results of multiple research studies.

“For the past 25 to 30 years there has been a debate about how much training you have to do to get an increase in fitness. There’s been a bit of conflicting research,” Rhea explains. “Using a meta-analysis, it is possible to synthesize the results of a large body of research. Areas such as psychology have gotten really good at that, but my field has not taken advantage of the technique.”

Rhea looked at two groups of exercisers, “trained” and “untrained.” The trained group includes people who have strength trained consistently for at least one year. Untrained individuals have not.

Rhea found that untrained people benefit most by lifting weights three times a week, at a fairly low intensity (50 to 70 percent of their maximum weight). Trained individuals, however, should only lift twice a week, at 70 to 90 percent of their maximum. At less than 70 percent intensity, trained individuals did not see much improvement. Rhea says that is because their bodies were used to stress and did not adapt to meet the demand.

“When you first start exercising, don’t lift too much, but go three days a week. As you become more highly trained you have to work harder but not more,” he says.

Both groups got the most benefit from performing four sets of exercises for each muscle group. Strength gains begin to plateau and drop off above four sets.

“There is more benefit from higher frequency and intensity, up to a point. Maximal strength benefits occur at four sets—the strength increases are about double what you’d get at one set. However, one set does provide some strength gains,” Rhea says.

For some people, slight gains are enough. Not everyone has the time or the motivation to perform four sets of exercises for every muscle group. Rhea says a good trainer will tailor the exercise prescription to the individual.

“How much strength gain do you need or want? If you just want to be active and don’t have a lot of time, one set may be sufficient.”

Some people, however, do need to maximize their strength gains. Doctoral student Mark Peterson studies elite athletes, such as professional athletes and Olympians. Combining the results of 37 studies, he found that elite athletes can maximize strength training by performing eight sets per muscle group, twice a week, at about 85 percent intensity.

“For an athletic population, optimizing training effect is one of the most important objectives of sport conditioning,” he explains. “Not everyone wants to optimize their training. Athletes have to. At a university, for example, an athlete can lose his or her scholarship, or get cut from the team.”

Peterson says that for most college and elite athletes, the athletic off-season and preseason lasts only a short time. Optimization of training means that an athlete can experience the most training effect, per unit of time, to prepare for competition.

Peterson points out that the optimum number of sets applies to each muscle group, not each possible exercise.

“For example, if you do squats and dead lifts in the same workout, these work essentially the same major muscles. You do not need to do eight sets of each. Four of one and four of the other would qualify,” he explains.

Peterson and Rhea presented their findings at the World Congress on Sport Science in Athens, Greece in October 2003. The meeting is sponsored by the International Olympic Committee. Rhea also presented at the National Strength and Conditioning conference in Indianapolis. His study was published in Medicine and Science in Sport and Exercise. Peterson’s study is pending publication in the Journal of Strength and Conditioning Research.

“I think this research has gotten a lot of attention because we’re using more advanced methods than in the past on a really hot topic,” says Rhea.

Peterson agrees. “I feel that this research will help shape the field of sport conditioning. Until now nothing’s been done like this. There have been lots of narrative reviews, but no meta-analysis. We feel the meta-analysis is a good way to get an objective look at the research.”

Rhea and Peterson work with the athletic department at Chandler-Gilbert Community College, the ASU East fitness center, and the Mesa Community College Fire Academy. They work with faculty advisor Brent Alvar, a joint faculty member at ASU and CGCC. In addition to teaching, Alvar runs the fitness center.

“Our grad students work as adjunct faculty for CGCC,” he explains. “They’re getting some unbelievable professional experience.” Alvar attended the World Congress in Athens with Peterson and Rhea.

“This is the pinnacle conference for our field. This is exciting for me—these are my first two graduate students and both got to present at this forum. They’re highly motivated and have really been focused,” he says.

In fact, the strength training research isn’t part of Rhea’s dissertation work.

“This project wasn’t part of my degree, it was just for fun,” he says, citing personal interest as his main motivation.

“I like exercise, I like science. When people see the science they’re more motivated, they know they’re on the right program. I want to tell them with confidence they’re on the best program.”—Diane Boudreau