What is the problem with this body paragraph below? It is two sentences: a topic sentence and a sentence that never ends. The Pro sees this problem all the time. Why do test-takers write like this? Because they are writing like they are talking to their best friend at Starbucks. There is nothing wrong with this style. Actually, the literary definition of this style is "stream of consciousness." That means writing whatever comes into your head.
First, every morning before work I go to the gym. At the gym I work out for two hours with my trainer Tom who makes me work really hard because I really need cardio for my heart so I use the treadmill for twenty minutes then I use the step machine for twenty minutes after which I use the rowing machine, which kills me because by then my arms and shoulders are so tired I just want to die but Tom tells me to go lift some weights so I do some weights for another twenty minutes and by the time I am finished, I am so tired I just want to die and go home and sleep all day but I can't because I must go to work.
What should you do?
First, every body paragraph must have three sentences: 1) topic sentence; 2) example; 3) conclusion. This three-part structure reflects the three-part structure of the essay itself. Next, when using an example (the long sentence above is really just an extended supporting example) use shorter sentences and periods. Why? Because the raters want to see if you can use punctuation. Also, the raters are not crazy about stream-of-consciousness style, or style in general. It suggests you are not really writing but speaking. The raters want to see a more formal writing style.
Want to know more body paragraph strategies? It's all in the book.