To monitor heart rate during workouts, several methods can be used. Firstly, heart rate monitors, which can be worn as wristbands or chest straps, provide real-time feedback. Secondly, fitness trackers and smartwatches often include built-in heart rate sensors. Thirdly, using traditional methods like taking the pulse at the wrist or neck during exercise can be effective. Lastly, specialized gym equipment like stationary bikes and treadmills often have integrated heart rate measuring systems, helping users stay within target heart rate zones for optimal results.