Hotel Villa Rolandi (Carr. Sac Bajo 15–16, tel. 998/999-2000, www.villarolandi.com [1], 9 a.m.–8:30 p.m. daily) has a full-service spa that specializes in using the positive energy and elements of the ocean. A full line of massages, body treatments, and facials is offered.
In downtown Isla, Casa Luz Spa (Av. Juárez btwn Calles Bravo and Allende, cell. tel. 998/734-5326, casaluz_280 [at] yahoo [dot] com [dot] mx, 7 a.m.–8 p.m. Mon.–Sat.) offers a range of massages and body treatments in a renovated home. Massages run US$38–88 (30–90 minutes), facials US$29–67 (1.5–2.5 hours), and body treatments, including wraps and exfoliations, cost US$37.50–72. Some treatments are available at your hotel, too.
Yoga classes are offered at two hotels on Isla: Elements of the Island (Av. Juárez btwn López Mateos and Matamoros, tel. 998/877-1715, www.elementsoftheisland.com [2], 8 a.m. Thurs.–Tues., US$10) and Na Balam (Calle Zazil-Ha No. 118, tel. 998/881-4770, www.nabalam.com [3], 9 a.m. Mon., Wed., and Fri., US$15). At either place, ask about monthly rates if you plan to stay awhile.
Links:
[1] http://www.villarolandi.com
[2] http://www.elementsoftheisland.com
[3] http://www.nabalam.com