Final answer:
Devin should decrease the duration of his workout to bring his heart rate down into his target zone of 132 to 170 beats per minute. Exceeding this zone could decrease his cardiac output and not be beneficial for his workout. the correct answer is (Option D) decrease the duration of his workout.
Step-by-step explanation:
Devin is working out on the elliptical and his heart rate is currently at 178 beats per minute, which is above his target heart rate zone of 132 to 170 beats per minute. To achieve the best possible workout while staying within a safe heart rate zone, Devin should:
(Option D). decrease the duration of his workout
This is because Devin's heart rate is already in a high zone, and it is important to avoid overexerting himself. To promote cardiovascular health and achieve an efficient workout, it's important to maintain a heart rate within the target zone, which optimizes cardiac output (CO). When heart rate increases above 160 beats per minute in a healthy young adult, the cardiac output may actually decrease due to decreased stroke volume (SV), as there is less time for the heart to fill with blood between beats. It is crucial to adjust the workout intensity to ensure that Devin remains within his target heart rate zone.