1. Drink up.
Headaches, cramps, fatigue, as well as larger problems like increased risk for DCS can all be pinned on poor hydration. Dive nutrition experts recommend drinking half your body weight in ounces — so 75 ounces or 9 cups for a 150 pound diver — especially on the days leading up to a dive. All liquids count (well, except booze), but water works best.
2. Warm up.
Most of us wouldn't step onto the golf course, tee up and start driving away without taking a few easy swings to get the blood flowing. It's equally wise not to start hauling heavy equipment and jump into the water without warming up. A good warm-up boosts circulation and lubricates your joints and muscles so you can shimmy into your wetsuit, hoist your tanks, and get up and down the ladder with ease. And it's easy to do. Perform a couple of simple squats. Do push-ups against a wall. Put your hands on your hips, and twist your torso left and right. Make easy windmills with your arms. Pay attention to places in your body that feel tight and give them a stretch. That's it. With just two minutes of easy activity, your muscles and joints are ready for the rigors ahead.
3. Flex your feet.
Unless you're a ballerina, the only time you spend an hour or so pointing your toes and flexing your feet is when you're 40 feet below, finning like a fish. The result can be painful foot cramps. The best way to avoid them short of dancing in silk slippers: Sock Scrunches. This simple move strengthens the muscles that support your arch, so they're less likely to fatigue and cramp up on your next dive."
How To: With bare feet, grab and scrunch a sock with the toes of your right foot and, keeping the heel planted, lift it off the floor. Hold for one second. Release and repeat until your foot fatigues. Repeat with the left foot. Do it twice a week.
4. Calm your calves.
Like your feet, your calves are prime territory for dive-wrecking cramps. Keep those muscles strong and calm with a simple seated calf raise.
How to: Lean against the wall with legs bent 90 degrees as if sitting in an invisible chair. Rise slowly onto the balls of your feet. Slowly lower yourself until your heels just touch the floor. Repeat until your calves fatigue. Finish with a good stretch. Do it twice a week.
5. Train Your Brain.
In a sport that demands gear assessment and occasionally high-pressure problem solving, mental fitness is a must. You can train your brain to respond coolly to high-stress dive situations through visualization. Mentally rehearse upcoming dives, including any emergency procedures that might arise. Pause at key points during the dive (such as before descending, once arriving at the bottom, etc.) for a quick assessment. Relax, breathe, and check yourself, your gear, your buddy and your surroundings. Then dive on.
source : http://www.sportdiver.com/keywords/health-and-fitness/6-sneaky-ways-to-make-every-dive-better?cmpid=apenews05122014&PodID=030&spMailingID=20761040&spUserID=MzM3NDY1OTE5NjES1&spJobID=320724027&spReportId=MzIwNzI0MDI3S0