It is generally assumed that heart rate is fairly constant, becoming gradually elevated during periods of exertion then reducing during rest.
The time period between the impulses that stimulate the heart to beat (known as R-R Interval) actually varies significantly for a constant average heart rate.
This variation known as Heart Rate Variability (HRV) can provide interesting information about the subject, such as:
- Indication of over-training (1) (2)
- Monitoring recovery from a competition or workout (3)
- Estimating Ventilatory Threshold and Anaerobic Threshold (4) (5)
- Identifying when the athlete is able to undertake hard training (6)
Various parameters have been established to classify HRV, the most notable being SDSD,; RMSSD; SD1 and SD2
This app calculates and displays these parameters in pseudo real time (update every 5 seconds based on the most recent 60 heartbeats). Also displayed is a histogram of the most recent SD1 values
In order to maintain reasonable stability in the parameters it is necessary to remove ectopic beats from the dataset. Ectopic beats are when there is a short R-R interval followed immediately by a long R-R interval, the average of the two being similar to the R-R intervals either side of the ectopic beat.
1. This app is for general interest only and SHOULD NOT be used for any clinical purpose.
2. CONSULT YOUR PHYSICIAN before undertaking any strenuous activity
3. This app requires a Polar Wearlink+ Transmitter With Bluetooth (Available from Amazon)
- NOTE If you have a Bluetooth Low Energy Chest-strap such as Polar H7 or Zephyr HxM check out the new app HRVxt
4. App has been tested on Samsung S3 and S4
1. Effect of overreaching on cognitive performance and related cardiac autonomic control. Dupuy et.al, Scand J Med Sci Sports 2012
2. Decrease in heart rate variability with overtraining: assessment by the Poincare´ plot analysis. Mourot et.al, Clin Physiol Funct Imaging (2004) 24
3. Heart rate variability before and after cycle exercise in relation to different body positions. Barak et.al; Journal of Sports Science and Medicine (2010) 9.
4. Use of Heart Rate Variability to Estimate LT and VT. Karapetian et.al; Int J Sports Med 2008; 29.
5. EFFECTS OF HIGH-INTENSITY INTERVAL TRAINING ON HEART RATE VARIABILITY DURING EXERCISE, FRONCHETTI et.al; Journal of Exercise Physiology online
6. Endurance training guided individually by daily heart rate variability measurements; Kiviniemi et.al; Eur J Appl Physiol
Andrew Flatt has an excellent blog on HRV training that can be found here: http://hrvtraining.com/
The Pro version of this app, now available (search Heart Rate Variability - Pro) will save all the R-R intervals (in mS) to a file that can be imported into a spreadsheet or Kubios HRV analysis software. In addition, a separate file will be generated that records all the parameters displayed on the screen, with the line numbers in the R-R file that were used to generate those values.
- Added LF/HF live display
- Ectopic beat detection now more aggressive
- App saves 2 files after approximately 200 beats have been received, File 'year-month-day-time-r2r' contains 60 beats.
- Minor bug fix for users who have experience a crash