Unless you either cut way back on calories or log much more workout time, you will likely pack on the equivalent of a honey-cured ham in extra weight every five years after age 35. But we have the antidote to the weight gain that can come from an age-related decrease in metabolic rate: an indoor cardio interval workout that’s a lot more fun than slogging away miles on a treadmill like a hamster on a wheel.
"By splitting your indoor cardio session between several different exercises, you'll burn more calories and never get bored," says Jeffrey Dolgan, an exercise physiologist at Canyon Ranch, a fitness retreat in Massachusetts. "You'll also prevent your muscles from adapting to one movement, and the less they adapt, the faster they'll grow." And if you add intervals (alternating short bursts of all-out effort with active recovery) to your training, you'll torch 90 percent more fat than training at a consistent pace, according to scientists at Laval University, in Quebec.
Run through the following 45-minute routine twice a week. Warm up with five minutes of each exercise at a "conversational" pace, and then complete a six-minute circuit in which you alternate four times between 30 seconds of intense effort and one minute of active rest. You'll be rewarded with a flatter stomach in record time, without feeling like a hamster on a wheel.
Face away from the console. You'll burn significantly more calories than if you assume a forward-facing position. "We're not designed to walk backward," explains Dolgan, "and to do so you need to engage many more muscles and work harder to keep your body upright." Mix up the depth and pace of your stepping as well to prevent your muscles from adapting. If you normally take shallow steps, for example, do deep, slow steps for two of the 30-second intervals.
After your warm-up, increase the resistance as if you were climbing a hill, and stand up and sprint for 30 seconds. "Not only will you use a different set of muscles--including those in your core-- but you'll break up the monotony of your ride," says Dolgan. He also advises against reading and riding. "If you're able to catch up on the news, you're not going fast enough." Aim for a cadence of 80 to 100 rpm.
Form is everything on the rower, especially when you're giving max effort. Initiate the drive with your legs, and then pull the handle into your sternum, says Dolgan. On the recovery, keep your legs flat as the handle travels away from your body, and then allow your torso to pivot over your hips as you bend your knees to return to the starting position.
After your warm-up, increase the angle of the incline to 1 percent. British researchers found that this angle most closely approximates running outside, causing you to burn just as many calories as if you were pounding the pavement. "Your indoor time might suffer as a result," says Dolgan, "but you'll shed pounds faster."