Standard push-ups build overall strength. You may think you only work your arms dynamically, but your back and leg muscles have to hold you up statically.
A variation is to push up and down on the poolside. This is a great arm and upper body workout. Slowly raise and lower yourself in and out of the water. Try different hand positions, closer together or further apart.
Next turn around, with your back towards the poolside, and push up that way. You'll exercise a different set of muscles.
As you get good with this, add more clothes to make it more challenging.
Push-ups get tough in heavy kit.
Do at least 10 push ups to get started. If this is a challenge, then you'd better start practicing right now. If you cannot do push-ups correctly or not enough of them, then start doing kneeling push-ups right now, start today. Start building the muscles that you probably had no reason to use lying around your house.
In shallow water position yourself as shown. Facing downwards lower your body so it just touches the water surface, keep legs together and use your toes (or knees) as the pivot point. If this exercise is too difficult, pivot off your knees instead of toes by flexing knees. With your fingers pointing forward, place your hands below your shoulders.
Push up by straightening your arms until your elbows are locked, then return to the starting position (with your chest just touching the water). Keep hips and waist straight and your body in a straight line throughout. Exhale as you push up; inhale on the way back down before you contact the water.
Perform this motion in a continuous manner. Do as many repetitions as you can, without a time limit. Stop the exercise when the movement becomes forcibly strained.
Finally move into almost knee deep water.
Immerse yourself fully and then push your body up and out of the water, which is quite a challenge when your wear lots of clothes.
This is great fun, but rather exhausting.
The Hindu Push-up is a staple exercise in the training routines of Asian lifeguards. Many believe it originated in India.
It consists of a dynamic full body movement that will build strength and flexibility in your chest, shoulders, back, hips, and triceps.
Another benefit when doing it in water is that it will prepare you for surf swimming. You get used to water washing over your head while you exercise.
Get in position by standing with your feet slightly wider than shoulder width apart, in knee deep water. It should be deep enough so you can fully submerge.
Take a deep breath and bend down and place your hands on the floor while keeping your arms and legs straight, with your head pointing down into the water.
Now make sort of a downward swooping motion with your body. Bring your body deeper under water by bending your elbows.
When your head gets close to the ground, continue moving your torso forward by arching your back. Lower your hips so they will now be near your hands.
Bring your head and shoulders above water and take a deep breath. Make sure to get a good stretch in your back.
Return to the starting position and repeat.
This push-up is performed exactly like the Hindu Push-up,
except when you return to the starting position,
you follow the same swooping motion you make on the descent in reverse.
It gives those muscles a bit more of a workout than Hindu Push-ups.
Sit in knee deep water. Bend your knees at a 90-degree angle and put your feet flat on the floor. Get a friend to hold them down, if possible. Place your hands on the side of your head.
Press your lower back against the floor to begin the movement with your face under water, curl up and touch your elbows to your knees (count one), then return to the starting position.
Exhale as you come up; inhale when upright. Perform as many sit-ups as you can in 60 seconds.
Stop when the movement becomes forcibly strained, you feel nausea in your stomach, or when you start to lift your buttocks off the floor at the beginning of each repetition.
Move to slightly deeper water so that your face gets fully submersed during each repetition.
This will prepare you for lifesaving in the sea, where waves wash over you.