Marco wants to improve his cardiorespiratory fitness. which type of activity would be the most effective to achieve this goal? resistance training three times a week swimming three times a week yoga four times a week weight lifting every other day

Marco should choose swimming. Resistance training, weight lifting, and yoga do not offer the type of activity needed to improve cardiorespiratory fitness, whereas swimming does. swimming requires constant use of the muscles, and this will increase his heart rate and need for oxygen.