A well-toned physique is vital to feeling comfortable in a swimsuit, luring fickle ice-cream vendors, and defending precious sand castles against destructive mobs of sand crabs. Get into beach-dominating shape with today’s Groupon: for $39, you get a five-class fitness pass to Core Studio in Plainville (a $90 value). This deal expires September 18.

The attentive trainers of Core Studio sculpt bodies and impart fitness-focused wisdom within an intimate, boutique-style facility. Guests can take their pick of five group classes, all of which inspire camaraderie among buffness buffs, keeping muscles motivated and preventing predatory medicine balls from picking off stragglers. Zumba, propelled by invigorating music and custom choreography, entertains as it chases off rhythm-phobic calories. Yoga sessions revitalize lungs and limbs alike, and cycling and strength training forge firmer cores and promote balance, stamina, and endurance. Check the schedule for class times.

Complimentary towel service and fully equipped men's and women's locker rooms supply guests with everything they need for post-workout pampering. Though additional services are not included with today’s Groupon, students seeking exercise extra credit can also turn to Core Studio for personal training or mettle-testing boot-camp courses. Female trainees may opt for a sexier species of workout in fantasy fitness classes specializing in sultry dance moves and introductory dragon riding.