Julie Ennis did not look like she was having fun. As she pushed at the weight machines, it was clear from her grimaces and groans that her muscles were working a lot harder than they felt like working.
Standing by with a clipboard and offering encouragement was Brandon Jonker, a personal trainer at Discover Strength in Minneapolis. "You are absolutely crushing this right now," he said as he guided the 39-year-old Maple Grove mother of four through the torture -- er, workout.
Aided by Jonker's supportive patter, countdowns and the occasional helpful push, Ennis worked each weight until she appeared to reach the point that fitness authorities typically advise people to aim for: the point at which Ennis would feel that if she summoned all her strength, she couldn't possibly do one more rep.
Then Jonker would have her do a few more reps. Sloooowly.
"With every workout, we overload in weight or in reps, every time we do each exercise," Jonker explained. "It's really taking her past the point of fatigue."
It was a tough workout but at 30 minutes a quick one, and with another appealing tradeoff: At Discover Strength, Ennis is told she only needs to do one or two of these arduous sessions a week to stay fit.
Strenuous but short and infrequent workouts are the key to high-intensity resistance training, a technique gradually gaining popularity across the country, including at Discover Strength, a local chain with facilities in Plymouth and Chanhassen and, most recently, downtown Minneapolis. Proponents say high-intensity training can deliver all the benefits of other forms of exercise without requiring hours each week of plugging away on a treadmill or mat.
"We need much less exercise than we think we do -- it's about intensity rather than duration," said Luke Carlson, Discover Strength's founder and CEO, who has also co-authored a training guide ("The Female Athlete: Train for Success," Wish Publishing, 2004) and served on the strength and conditioning staffs of two Twin Cities high schools and the Minnesota Vikings.