给定一篇文章和一个关键词，找出该关键词在文章中的情感倾向（正面、负面、中性）。输出情感倾向。
文章：A new study shows that increasing your physical activity can increase your level of happiness. The study found that people who exercised for just 20 minutes a day reported feeling happier than those who didn't exercise at all. The results were consistent across all age groups and genders, and were not affected by the intensity or type of exercise.
关键词：exercise
情感倾向：正面。