How can i control the variables for an experiment with a sport like swimming in terms of speed?

We are testing for our research paper what and how are the different factors afffect the speed of a swimmer. How can we control the variables? Is changing the temperature one example?How can i control the variables for an experiment with a sport like swimming in terms of speed?
Yes, temperature is one. To control the variables during an experiment into causes of something or other, you need to keep all of the factors for which you're testing (and other ';environmental'; factors that may affect the experiment) the same from test to test, and just change ONE of them at a time.





In your case, the likely factors are: temperature of the water (which is an easily measurable proxy for density of the water), chlorination level, length of the swim, maybe height and weight of the swimmer, what the swimmer is wearing perhaps, etc.





You could also test for other possibly affective variables, like the muscle mass of the swimmer (which you can obtain by seeing how much they can lift with arms and legs divided by their weight), time of day (fatigue), size of hands and feet of the swimmer, length of arms and legs, etc.





The key in controlling the variables, again, is to keep them all constant (even the ones for which you're not testing) and change only one. So, for example, if you're testing for water temperature's effect on swimmer speed, you'll want to use the same swimmer every time, at the same fatigue level, dressed in the same suit, in the same pool, doing the same length of swim, but change the temperature of the water a few degrees at a time while you take readings.





If you want to test for muscle mass effect, keep everything else the same, but change swimmers (use a fat guy, a skinny guy, a body builder, a runner, etc.).





If you don't control the variables as above, what happens is you end up accidentally changing two or more variables at once (for example, two different swimmers in two different water temperatures). Then you don't know if the differences in speed are due to the different swimmers, or the different temperatures, and your experiment is invalid.





Get the idea?





Good luck!How can i control the variables for an experiment with a sport like swimming in terms of speed?
You can control variables related to the pool: temperature, filtration, water depth, chlorination, etc.





You could also control variables related to the swimmer: different types of suits, goggles, swim caps, etc.





The main thing is that you want to try to only change one variable at a time, and keep everything else the same- that way you'll know if that variable is really having an effect.
yea..you got it changing the temperature, the size of the pool, different chemicals in the pool, the type of pool, hmm what else, even things such as the ph of the water, the hardness of the water. stuff like that, depending on what your trying to test. Nice Question, it really got me thinking.