The mean score is 60 out of 100 and the standard deviation (in other words, the variation in the scores) is 15 marks (see our statistical guides, Measures of Central Tendency and Standard Deviation, for more information about the mean and standard deviation).
What Are the Six Different Types of Swimming Strokes? Swimming provides all-around, low-impact body conditioning as well as exciting competition. Competitive swim meets allow only four strokes -- butterfly, backstroke, breaststroke and the crawl. Two other strokes -- elementary backstroke and sidestroke -- contribute to swimming longer distances, as different sets of muscles are used. The fastest stroke for most swimmers is the front crawl.
Freestyle swimming simultaneously works upper-body and lower-body muscle groups. Photo Credit Ryan McVay/Photodisc/Getty Images. Freestyle swimming, also known as the front crawl stroke, involves movements that work muscles throughout your midsection, upper and lower body.Strengthening individual muscle groups can help improve your form and efficiency of the freestyle swimming stoke.. Different muscle groups contribute to particular elements of the freestyle stroke, and you can avoid overuse injuries by strengthening those muscles.trengthening individual muscle groups can help improve your form and efficiency of the freestyle swimming stoke. . Different muscle groups contribute to particular elements of the freestyle stroke, and you can avoid overuse injuries by strengthening those muscles.