Which of the following is a method for determining training intensity?

Heart rate monitoring is a method for determining training intensity because it provides a quantifiable measure of the effort exerted during physical activity. By measuring heart rate, individuals can assess how hard their body is working during exercise, which is crucial for tailoring workouts to meet specific fitness goals.

Training intensity can be expressed as a percentage of the maximum heart rate, helping to establish whether the workout falls into low, moderate, or high-intensity categories. This allows individuals or trainers to adjust exercise intensity to optimize performance, improve cardiovascular fitness, and guide recovery strategies. Monitoring heart rate also helps in maintaining appropriate intensity levels throughout different phases of training, ensuring that sessions are effective and aligned with fitness objectives.

Other options do not directly measure training intensity. For example, time management pertains to planning and organizing workout schedules, while diet tracking focuses on nutritional intake rather than exercise exertion. Weight lifting is a form of resistance training but does not inherently indicate the intensity of the workout without additional context, such as the weight used or the number of repetitions performed.