Since 2009, Michael Wollpert, a local trainer with a serious following, has operated a facility for other trainers to use with private clients. In January, he opened this River North studio to bring his effective regimen to the masses: Trainology offers more than 50 classes a week based on the way Wollpert himself trains for a packed schedule of triathlons, cycling events, and multiday adventure races. 

The draw? Sessions combine cross-training intervals in a way that minimizes intensity and impact—reducing the risk of injury, according to Wollpert. For example, hike and glide classes, an alternative to treadmill running, use glide boards to tone often-ignored lateral muscles. And the signature Trainology class alternates between walking, jogging, or sprinting and strength training on suspension equipment. Hardcore adherents can track heart rate and calories burned in real time. Drop-in rate: $25.