Dehydration and Sport Performance

Staying hydrated in the Texas summer heat is very important for sport performance. There have been numerous studies on the effects of dehydration and exercise.  Most experts agree that 2% dehydration will lead to a drop in sport performance of up to 21%.  Furthermore, a decline in cognitive function occurs at 2% dehydration including skill sports such as soccer.

There are several reasons for the drop in production.  As you start to dehydrate, there is a decrease in plasma volume.  This causes a decrease in stroke volume and a decrease in skin blood flow.  With less blood going to the skin, it becomes harder to sweat and cool your body.  Ultimately, your core temperature rises which begins to take a toll on your body which may cause cramping and heat exhaustion.

I've seen several people wearing extra clothes or "sweat" suits to try and lose more weight.  The truth is, those people will lose more weight BUT it is mostly water weight which returns as soon as they are properly hydrated.  Instead of focusing on weight loss for the afternoon, focus on performance and intensity.  Proper exercise will benefit you more in the long run than "sweating" out a few extra water pounds.

Therefore, expert recommend properly hydrating yourself before your activity.  Drink at least 4 liters of water 24 hours before your activity if not every day.  Drink another ½ liter 1 to 2 hours before your event.  Then drink plenty of fluid during your activity and include a sport drink if you are exercising for more than 1 hour to replace any electrolytes lost in the sweat during your activity.

Building a Strong Core

Which ab exercise is most effective for building a strong core?  Everyone has their favorite.  They all seem to work well but let’s look at the science behind these exercises to see which ones may have an advantage.

Clark et al (2003) concluded that the stability ball crunch was more effective than 5 other ab exercises including leg raises and traditional crunches.  More specifically, Sternlicht et al (2007) was able to show that placing the stability ball near the lower back versus the upper back, activated the abdominals more than the traditional crunch.

Escamilla et al (2006) tested 12 different ab exercises.  The exercises that kept finishing near the top were the Power Wheel roll-out, the hanging knee-up, and the reverse crunch on a 30 degree incline.

In conclusion, a strong core is important for athletic performance and the prevention of low back pain.  Train your abs as you would train your other muscles: 1 to 2 times per week.  Use a variety of movements and try one or all of the following exercises: stability ball curl-up, Power Wheel roll-out, the hanging knee-up, and the reverse crunch on a 30 deg incline.

Upper and Lower Abs

Should you train lower abs differently from upper abs?  There have been numerous studies that tried to answer the same questions for years.  Most studies agree that every abdominal exercise excites the muscle fibers of the lower and upper abs equally.  But a few at least one study supports the notion of adding reverse curls to your ab exercise routine.

A study by Clark et al (2003) tested the upper abs and lower abs from 8 healthy subjects.  Using electrode placement on upper and lower abs, the results showed no significant difference between upper abs and lower abs on six different ab exercises.

On the other hand, a study by Willet et al (2001) reported small differences between lower abs and upper ab activity in their study.  For example, the curl-up and reverse curl both produced similar results for the upper rectus abdominis; but, the reverse curl seemed to excite the lower rectus abdominis more than any other exercise.

In summary, most experts agree that all ab exercises will strengthening your abdominal wall and minimize low back pain.  But if you want to play it safe, doing both curl-ups and reverse curls will ensure your entire ab wall is strong and mobile.  Now showing off that abdominal wall is a different story.  Those six pack abs will only begin to show with a good diet and cardio plan as well.