Background Paragraph: Sometimes muscles and tendons get injured when a person starts doing an activity before they have warmed up properly. A warm up is a slow increase in the intensity of a physical activity that prepares muscles for an activity. Warming up increases the blood flow to the muscles and increases the heart rate. Warmed-up muscles and tendons are less likely to get injured. For example, before running or playing soccer, a person might jog slowly to warm muscles and increase their heart rate. Even elite athletes need to warm up ( Figure below ). 
Story: Two groups of runners attended a 5k event downtown. Brown group warmed up properly before the race, but Red group did no such thing and suffered the consequences.
Which group did a slow increase in the intensity of a physical activity? Which group didn't do a slow increase in the intensity of a physical activity? Which group didn't jog slowly to increase their heart rate? Which group didn't jog slowly to warm muscles? Which group jogged slowly to increase their heart rate? Which group jogged slowly to warm muscles? Which group was less at risk for muscle injuries? Which group was less at risk for tendon injuries? Which group was more at risk for muscle injuries? Which group was more at risk for tendon injuries?