Stand Up Paddle Boarding (SUP) may not provide a medically significant workout, according to new findings by the American Council on Exercise (ACE).

The hobby-sports has been touted as a fun summer exercise, however two recent ACE studies show that to get the comprehensive core benefit many people mention in reference to SUP, you need to have relatively advanced form or technique. Furthermore, if you are using the sport as a means of achieving a good workout, users must paddle with intent to reap the health rewards.

While beginners fell short of raising their heart rate and burning enough calories to consider SUP a significant exercise, advanced paddlers saw benefits. ACE scientists speculate that it takes a bit of experience and skill to become balanced, especially on the open water. “To get a good workout you have to have a lot of torso twisting to get moving and build enough resistance, and that’s a hard skill,” an ACE representative told SGB. “That’s where you get these core benefits.”

The two studies were broken into open water and pool SUP. Beginners and advanced SUPers got closer to the same exercise benefits during a pool workout, but as soon as they were out on the open water the output was split.