According to the progression principle, the cardiovascular fitness of one individual will continue to increase while the improvement of the other person will be limited. The majority of the time, exercising is beneficial. If you exercise a few times per week, your cardiovascular health will undoubtedly improve. However, if you repeat the same exercise routine every day, your body becomes accustomed to it and stops improving. However, by using the progression principle, you gradually increase the difficulty of your workouts over time, improving your cardiovascular fitness.