Japan's professional sports clubs are attracting a wave of investment, as a fitness club, clothing chain operators and entrepreneurs look to cash in on the sports world's potential ahead of the 2020 Games.

At the training camp of J. League first division soccer side Shonan Bellmare, trainers from fast-growing fitness club chain Rizap Group Inc. were seen instructing the team's players on how to strengthen their bodies, in a similar way to how they coach members of their gyms.

Rizap, famous for its TV commercials touting dramatic before-and-after images of customers' bodies, including celebrities, acquired the management rights of Shonan Bellmare in April.