Fitzgerald is not having trouble with his lifts. He wants them that way.
Supporters of super slow training regimens such as the one Fitzgerald uses at a YMCA in Quincy, Mass., say they can build more muscle. Fitzgerald said he's added a lot in the three years he's been doing super slow.
"I went from 165 to 180 (pounds) and I'm pretty solid," he said. "I'm 12 to 14 percent body fat. That's not too bad for a 50-year-old."
Researchers and exercisers say super slow workouts are an effective way to wear down muscle, triggering the body to respond by making the muscle fiber grow. But they warn that super slow can be very hard work.
In 1993 and 1999, exercise physiologist Wayne Westcott, who has done studies at the same Y that Fitzgerald uses, compared super slow and conventional workouts in people Fitzgerald's age. Fitzgerald was one of his experimental subjects.
The super slow group lifted up in 10 seconds, doing five repetitions. The conventional groups lifted up in two seconds, doing eight to 12 repetitions. All the trainers averaged four seconds in lowering the weights.
Strength improvements in the super slow groups were about 50 percent greater than in the conventional groups, Westcott said.
Super slow workouts have special value on the downside, said Jeffrey Potteiger, an exercise physiologist at Virginia Commonwealth University. It's a new version of what veteran weight trainers know as doing negatives, he said.
Negatives work on the part of the lift in which the weight is lowered. Positives are the part in which the weight is raised.
The body doesn't recruit as many muscle fibers on a negative movement, so a slow negative means "a tremendous amount of force is being applied to fewer fibers," Potteiger said. This extra work should build more muscle.
Compared with conventional workouts, super slow is super fast, said Frederick Hahn, a trainer and gym owner in New York City and author of one of the current spate of books on super slow workouts, The Slow Burn Fitness Revolution.
Hahn's regimen requires only 30 minutes a week: 10 seconds up and 10 down per lift, with only three to six repetitions. And this set of lifts is done only once, while conventional regimens require each set to be done two or three times.
Super slow lifters also can drop aerobics. The combined demands of super slow and aerobics break down muscle faster than it can repair, Hahn said.
That happened to Fitzgerald, who described himself as a former 10K and half-marathon runner.
"It was killing me," he said. "I cut it out because it was cutting into my recovery ability."
However, Potteiger thinks there's no proof that super slow can replace an aerobic workout. The idea that super slow workouts can improve cardiovascular fitness "is true if you are doing nothing now," he said.
Similarly, although super slow can burn calories, one new study found that conventional weight training burned more. Researchers at the University of Alabama at Birmingham looked at seven men with an average age of 25. The men did about 30 minutes of work in each session of each type of workout.
Conventional lifts used 45 percent more energy than did super slow, which had an energy demand equivalent to a walk, according to their report in the February issue of the National Strength and Conditioning Association's Journal of Strength and Conditioning Research.
Switching from conventional to super slow is not an easy change of pace, Fitzgerald said. Slowing down the movements to the creep of the super slow pace may require coaching, he said.
And super slow is a demanding workout, Westcott and Fitzgerald warned.
Super slow takes a lot of practice to learn, a lot of concentration in keeping the form right and the mental stamina to keep pushing weight while your muscles ache.
"It's not for everybody," Fitzgerald said.
In Westcott's studies, 95 percent of the people who did super slow chose not to continue after the research ended.
Their feeling was, "Even though it did work better, I'll just stay with the standard because it will get the same results but it takes longer," he said.