Our perfect beach trip includes building sandcastles, vegging out with a good book, and slurping down some ice cold lemonade. But as much as we love to lounge in the sand, we also look forward to getting in some great exercise.

The shore is the perfect spot to switch up your routine with some fun (and effective!) high-intensity workouts. Check out these seven activities to maximize your time in the sun.

1. Beach Sprints

“When you’re running in sand you’ll have to push harder with every stride because the sand ‘gives’ underneath the weight of your body,” says SoCal-based trainer Mike Donavanik, C.S.C.S. This “give” ups the demand placed on your glutes, hamstrings, and quads—three of your body’s biggest muscle groups. The result: more muscle formed, more calories scorched, and athleticism gained. In fact, a 2013 study published in the Journal of Strength and Conditioning Research found that athletes who ran sprints on sand for eight weeks improved their 20-meter sprint performance significantly more than those who stuck to more stable surfaces.

Turn up the burn: Swap out a steady-state run for a series of sprints. Donavanik recommends running 10 to 15 30-second sprints in the sand, giving yourself 90 seconds of recovery between rounds. Start out on the packed sand close to the water, and once you handle that, increase the intensity even more by taking your sprints either into super-shallow water or up onto the looser, dry sand.

Related: Should You Be Doing A HIIT Workout?

2. Bodyweight Exercises

Who needs dumbbells when you’ve got a beach? When you’re in the sand, bodyweight workouts train your body’s small stabilizer muscles (because of that ‘give’), which are key for injury prevention. Create a quick circuit by combining large, compound bodyweight exercises such as squats, push-ups, lunges, and glute bridges for a total-body workout, recommends Colorado-based Kourtney Thomas, C.S.C.S. Drills like skips, butt-kicks, marches, and spiderman scrawls also become crazy-hard in the sand, says corrective exercise specialist Dani Almeyda, M.S., C.E.S., co-owner of Original Strength in North Carolina.

Turn up the burn: To get the most out of the bodyweight exercises you choose, Thomas recommends performing AMRAPs (as many reps as possible) of each move. When your form starts to break down, or you seriously can’t do any more, move onto the next exercise. Perform your circuit three to five times. To take it to the next level, try making your moves more explosive: Squats become jump squats, lunges become scissor lunges, and pushups become burpees, Thomas says. Since you won’t have a hard surface to push off, these moves will feel harder than ever.

3. Beach Volleyball

All that running, jumping, and diving after the ball will jack up your heart rate and challenge your muscles, resulting in a serious (and fun) calorie burn. In fact, you can burn up to twice as many calories playing volleyball in the sand than you would playing on a hard gymnasium floor, according to Harvard Medical School. What better way to get in a solid workout with your friends?!

Turn up the burn: Fewer players on the sand means more work for you. Try a game of one-on-one so you have to run, jump, and lunge over more surface area to defend your side of the court, says Hannah Davis, C.S.C.S., creator of Operation Bikini Body. She recommends playing for at least 20 minutes to tap into your fat metabolism.

Related: 5 Myths About Your Metabolism—Busted

4. Stand-Up Paddle Boarding

This water sport continues to gain popularity—and for good reason, Almeyda says. Propelling yourself through the water while standing on a board engages all of your muscles, while also challenging your balance and coordination.

Turn up the burn: Use Mother Nature to your advantage when looking for ways to make paddling more difficult. Increase the resistance by paddling against the wind, tide, or current. You can also try standing up on the board instead of kneeling for a greater core and leg workout. To stay safe, head out from the beach (most resorts have rentals) and stick to shallow areas.

5. Playing with Your Dog

To ensure you don’t laze away the whole day, get your pup involved. Just make sure you pack a ball or Frisbee. After all, one review published in the Journal of Physical Activity & Health found that dog owners were more likely to meet recommended physical activity guidelines than those who are Fido-free. And your dog’s seaside energy will certainly give you a workout.

Turn up the burn: Don’t make your dog do all the work. Once you throw the ball or Frisbee, jog or run after your pooch. If you’re feeling competitive, have someone else throw the ball and see if you can beat your canine to the prize, Davis recommends.

6. Swimming

We’d be remiss to overlook the many benefits to gain from breaking up your sand time with a dip in the ocean. “Swimming is resistance cardio that is low-impact but packs a major calorie burn punch because it involves your entire body,” Davis says. “So you can gain strength and stamina while still being extra-kind to your joints.” Talk about a combo deal.

Turn up the burn: If you think swimming is hard, try treading water. You can burn up to 40 percent more calories per minute treading water than you can swimming leisurely, according to one Harvard estimate. Just stick close to the shallows so you can give your legs a rest when needed.

7. Kayaking

This classic water sport will shine the spotlight on your core and back muscles while getting your heart rate up in a big way, Davis says. And, thankfully, most popular beaches offer kayaks for rent.

Turn up the burn: Tap into your competitive spirit by racing a friend to a nearby buoy or landmark, she says. For greater speed (and better results), focus on using your entire core to power each stroke—not just your arms.