rehydration

[Justin]

Myscience fair project is about rehydrating your body. I drank water one time, and gatorade the next time. I exercised and then took my pulse rate to try to determine what fluid would allow me to exercise for longer. I also played an entire basketball game drinking water one time and then gatorade the next. I am having trouble writing my results because when I say that my muscles felt fatiqued, that isn't something measurable. Can you please tell me why your muscles begin to feel fatiqued? I would appreciate any help you can give me. Thanks

[Lise Byrd]

Muscle fatigue can occur when your muscle cells aren't getting enough oxygen. They create a byproduct, lactic acid, which is toxic to the cells and cuases your muscles to hurt. Muscle fatigue can happen when you have been exercising for a long time, have not stretched out completely, or are using muscles which haven't been used in a long time.

To make your data more measurable, you may be able to compare how fatigued your muscles felt after drinking water or Gatorade by assigning a number from 1 to 10, 1 being "Perfectly fine" and 10 being "Extremely fatigued," for example. This can provide a useful comparison as long as conditions other than the drink-- the length of time exercising, amount of stretching done before and afterward, etc.-- are held constant.

Hope this helps,
Sonia

[carolinethorn]

Sonia had some excellent ideas and advice.
It is very difficult to work with results that are "subjective" measurements. I have worked with arthritis patients and there is a similar issue when trying to assess whether their joints are painful and whether the medication helps. We use a scale, similar to what Sonia described, for the "intensity" of the event (5= severe pain, 1= low pain, 0= no pain etc)
Another measurement you could take is how long you felt fatigued for or the "duration" of the event.

Something else you might want to consider is repetition of the experiment. Did you test more than once with water and more than once with gatorade? But you should consider about the order that you repeat the test and whether your muscles might be more tired from a previous test or your fitness might improve as the tests go on. This is usually discussed for experiments about learning and behaviour but might also be something to think about in your discussion section.

One last thing is that you didn't test with no fluid - which was the right thing to do because that might not have been safe. So you are comparing two variables against each other without a negative control rather than comparing each to a negative control to see which is better. It is a relative measurement rather than an absolute measurement. This is similar to the problem that drug companies have with testing cancer drugs. Some clinical trials can use a negative control or placebo that has no drug in it but for very serious illnesses like cancer it would be unethical to give a patient a placebo so they test the new drug against the standard treatment. Just something else to think about for if the judges ask you about the type of your study design.

best of luck,
caroline

[thetrans1ent]

Something else you might want to consider is repetition of the experiment. Did you test more than once with water and more than once with gatorade? But you should consider about the order that you repeat the test and whether your muscles might be more tired from a previous test or your fitness might improve as the tests go on. This is usually discussed for experiments about learning and behaviour but might also be something to think about in your discussion section.

Furthermore, consider repeating the experiment on different test subjects (i.e., other students). For more reliable results, consider finding these subjects via random sampling. Note that if you only do the experiment on yourself, your results may be questionable because being the person performing the experiment, you know what conclusion you want to reach, which may introduce bias.