It does not take many workouts with your UFit trainer to recognize that all exercises movements or even all types of exercise are not equal.  Aerobic exercise, resistance training, and flexibility/stretching exercises not only feel different, but they have differing effects on your cardiovascular system.
The most obvious type of exercise is aerobic exercise.  This type of exercise elevates your heart rate and improves both the heart’s ability to pump blood and improves circulation through the vasculature.  It is recommended to engage in moderate aerobic activity 150 minutes per week for cardiovascular health.  Exercises include anything that gets your heart pumping, e.g., brisk walking, cycling, tennis, etc.
Resistance training, or strength training, uses some sort of force (e.g., bodyweight, free weights, resistance bands, etc.) to help build muscle.  It does not directly improve cardiovascular health like aerobic exercise; rather, it helps transform body fat into lean muscle.  This indirectly improves heart health because excess abdominal fat is a risk factor for heart disease.  It is recommended to engage in strength training exercise at least two nonconsecutive days of the week.
Flexibility and stretching exercises also have an indirect positive effect on cardiovascular health.  They do not increase heart rate nor do they affect body composition.  Instead, they improve musculoskeletal health, which improves joint flexibility and lessens the potential for injury to muscles, tendons, ligaments, and bones.  Staying flexible and injury-free allows the body to engage in aerobic exercise and resistance training.  It is recommended to stretch not only everyday but also before and after every workout.
The bottom line is that all exercise is important in keeping your heart and the rest of the vascular system healthy.  Strengthening the heart muscle through exercise keeps away heart disease, damage to the arteries from high cholesterol, high blood pressure, and high blood sugar—all of which can lead to a heart attack or stroke.  Your UFit trainer can help you vary your exercise routine to have the most benefit, but always remember that some form of exercise is better than no exercise at all.