What Matters More in Spin Class: Speed or Resistance?

Going fast and building muscle are both important facets of indoor cycling—but here's what to do if something has to give.

By Cassie Shortsleeve

It's a common conundrum in indoor cycling: You hit a hard hill and realize you can't maintain your speed. So do you lower your resistance or slow down?

"I always tell people torque (resistance) is completely negotiable and RPMs (speed) is non-negotiable," says Victor Self, a master instructor at Flywheel. "Because we are doing high-intensity interval training, we always ask you to add torque or speed—but if you're not already going the speed we've requested, the interval won't be as effective."

So if you're struggling on a hill, drop the resistance and keep your RPMs where they should be. "This is how the pros do it," says Michele Olson, Ph.D., professor of exercise science at Auburn University Montgomery.

However, you don't want to cut the resistance excessively. The faster you can do a heavier amount of work, the greater your explosive power will be in your core and leg muscles, she says. Turning it up will get you the most bang for your buck, in terms of upping your aerobic andanaerobic power, she says.

Anaerobic training—which consists of shorter, more intense bursts—is important for everyday life (whether you're lifting heavy boxes or jumping over a curb), Olson explains. Aerobic power—which you build through working at moderate intensities for a longer amount of time (think: runs)—helps heart health and increases your ability to use oxygen effectively, she says.

Original research from Dr. Izumi Tabata found that when participants rode at a maximum effort for very short bouts—about 20-second sprints—they increased their aerobic power by about 12 percent and their anaerobic power by about 25, Olson says.

Why is that so important? When you're working both your anaerobic and aerobic systems (something that happens big time when you turn up the resistance), you burn both carbs and fat, speeding up weight loss, Olson says. "The afterburn from this type of exercise can last up to 24 hours and burn an extra 150 calories after heavy sprinting."

In the long run, the more power you put out per class, the more calories you torch, she says.

The bottom line: Master the basics at a lower resistance, then work toward keeping that resistance high to improve your fitness, says Olson.

reprinted from fitnessmagazine.com