1.Delta Heart Rate
The famous poet David Whyte once wrote, “All things change when we do.” That’s the principle behind the delta heart rate assessment. Delta (Δ), a letter in the Greek alphabet, means “change.” Hence the delta heart rate, or orthostatic heart rate, is a measure of the heart’s response to a change in body position.
Heart rate alters with changes in body position. Its increase and decrease depends on the workload demand on the heart muscle. If you lie down, for example, your heart doesn’t have to work as hard as it does when you are standing because it doesn’t have to pump blood upward against the force of gravity. Likewise, a sitting position elicits a lower heart rate measurement than the standing position.
Stress can also affect heart rate. Thus, delta heart rate can be used as an indicator of current stress. If you are overtraining, are on the verge of a respiratory infection, are suffering from a lack of sleep, or have recently changed your diet, for example, your delta heart rate will be higher than normal. Competitive athletes commonly use delta heart rate as an indicator of overtraining or pending immune compromise.
The most common way to measure delta heart rate is to record the heart rate when lying down and then when standing. The difference (standing heart rate minus sitting heart rate) is the delta heart rate. The change in heart rate values results when the heart responds to different workloads. Because a healthy heart can adjust efficiently to small changes in workload, a higher delta heart rate might indicate a less fit cardiovascular system. However, it could also indicate stress from internal or external conditions. Once a person has recorded multiple readings, the delta heart rate measure can be used as an indicator of cardiovascular fitness or stress.
In a lying position, the heart rate lowers to a value close to resting heart rate.
When we stand up, the cardiac system adjusts to this change in body position: the heart rate increases and then drops. Eventually, usually after about two minutes, the heart rate hovers around a new value (figure 2.2, S). The change in heart rate, known as delta heart rate, is the difference between P and S.
2. Recovery Heart Rate
Recovery heart rate measures the heart’s ability to return to its normal rate after exercise. It is a trainable heart rate, meaning that the more fit one becomes, the more quickly the heart rate returns to preexercise rates once exercise is stopped. Recovery heart rate is the time between the cessation of exercise and the heart rate’s return to its preexercise level. A common recovery heart rate measurement is one to two minutes, although total recovery may require as long as an hour. The shorter the heart rate recovery is, the fitter the person is. There are two types of recovery heart rate measurements: intrarecovery heart rate (within a workout) and interrecovery heart rate (between workouts):
- Intrarecovery heart rate is the time it takes for the heart to recover within one workout session.
- Interrecovery heart rate is the time it takes for the heart and specific muscle groups to completely recover between workout sessions.
Ideally, students’ intrarecovery heart rates recover (i.e., return toward ambient heart rate) very quickly. Some call the interrecovery heart rate the one that falls like a stone; that’s how quickly it usually recovers. Interrecovery heart rates that are slow to recover can indicate a less-fit cardiovascular system or be a warning of heart-related conditions.
With conditioning and the use of mindful recovery, students can learn to improve their recovery heart rates. In fact, to some extent, they can learn to consciously regulate their heart rates. Mindful recovery is also an excellent tool for managing stressful situations.
Mindful recovery involves the use of visualization, deep breathing, body positioning, and similar relaxation techniques to purposefully lower the heart rate as rapidly as possible. With practice, students can develop their own relaxation strategies. There are two methods of mindful recovery:
- Active recovery, which involves continuing to move gently
- Passive recovery, which involves stopping all exercise