HeHa Waterproof Health Tracker Get Fit Watch Step Counter Fitness Tracker with Heart Rate Monitor for Women Heart rate variability(HRV) is a relatively new method for assessing the effects of stress on your body. It is measured as the time gap between your heart beats that varies as you breathe in and out. Research evidence increasingly links high HRV to good health and a high level of fitness, whilst decreased HRV is linked to stress, fatigue and even burnout. HeHa heart rate monitor iPhone compatible is a new tool for you. By applying the appropriate calculations to Heart Rate Variabililty (HeHa HRV does that for you), you can better understand your nervous systems, cardiovascular systems, and respiratory systems in response to life's stressors. By acting on your HRV biofeedback insights, you can optimize your training, manage stress, improve health, and maximize your performance in life. HRV is affected by aerobic fitness. During exercise, HRV decreases as heart rate and exercise intensity increase. HRV also decreases during periods of mental stress. It's a powerful tool for athletes and coaches, providing useful information which can be used to adjust training programmes to best effect. Such as: Joggers, walkers, runners, cyclists, triathletes, hikers, climbers, skiers, weight-loss participants. HeHa Bluetooth heart rate monitor has built in breathing guides that allows you to use your respiratory system to gain control over your cardiovascular system and nervous system and track the effects. It helps train your breathing so you focus on each breath. Start it at anytime or any where, just take a few minutes at the office, stuck in traffic, on the train or before you start or end your day. Its wristband is made of a flexible, anti-allergic, durable elastomer material. It can worn in a colorful wristband or clip inside of your suit, so you can keep this companion with you at all times. Fits wrist circumference 7.87 inches (200mm) or small. Items shipped from Amazon and can be returned within 30 days and HeHa offer lifetime warranty.