Want to intensify your workout in the new year?
Try chilling your muscles in a cryotherapy chamber. If that's not your cup of tea, strap some electric stimulators onto your biceps while you're pumping iron.
These are just some of the latest, highest-priced fitness fads, yet the workouts seeing the most growth are actually some of the oldest around.
For aerobics, cross training grew by 14 percent, according to the latest survey by the Sports and Fitness Industry Association. High intensity interval training, was also up 10 percent, and regular old stair climbing saw 9 percent growth. The association's survey looked at fitness habits of Americans who said they work out at least 50 times per year.
If anything is new, it's water. Aquatic resistance workouts are growing in popularity, probably due to the aging population of active baby boomers. Water is easier on the joints. And on the other end, treadmills are seeing a rebirth among millennials.
Overall, the fitness industry has been growing at a million new club memberships a year since 2012, according to SIFA. These run from discount clubs with memberships as low as $9.99 a month to high-end boutique studio sessions commanding over $50 for 45 minutes. And the industry could get even bigger this year.