An assistant professor of exercise physiology at the University of Alabama suggests that heart rate variability “appears to be a very promising tool” in predicting fitness levels.
Mike Esco, the professor behind the research, wanted to find an objective test to predict how an apparently healthy athlete would preform in a physical activity on a given day. Esco, a doctorate in exercise physiology, was inspired to look for answers after he severely injured his back during a grueling day at the gym. He believes heart variability testing can be a good predictor of how someone in a physical profession may preform on a given day.
Heart Beat Variability
Doctors have long been studying heart rate – the number of beats per minute – as a quick way to gauge someone’s fitness. Esco decided that while heart rate is a good measure, looking at the variability between beats could tell us even more about our health.
“We think of the distance between each beat as consistent,” says Esco. “But in reality, that’s not the case. The more variability, the better. That’s indicative of a restful state.”
Esco explained that the variability between beats is an indicator of how the automatic nerve system controls the cardiovascular system. A large variability indicates a more parasympatheic state, synonymous with recovery, while less variability is associated with a more sympathetic state, which is typically active during exercise. Esco said the variability can be a great measuring tool in three different ways:
- Certain variabilities can help predict cardiovascular events.
- Comparing the variabilities over time can indicate how a person’s fitness is changing over time.
- Measurement can predict if a person is physically ready for exercise on a particular day.
For example, a person with a sympathetic variability may not fully be recovered from activity, and thus may not be ready for more exercise.
“Heart rate variability is so sensitive that it changes throughout each day,” said Esco.
Heart Rate Study
One study presented at the American College of Sports Medicine 2014 annual meeting examined the association between soccer players, heart rate variabilities and injuries. Researchers uncovered that players with muscle fatigue of contracture exhibited less variable heart rates and a higher likelihood of injury.
Esco said the next step is to determine a clearer association between heart rate variability and risk of musculoskeletal injury.
“The cardiovascular system is completely integrated with all the others, including the musculoskeletal system,” he says. “If it’s not recovered enough to deliver the optimum nutrients in blood on a particular day, the musculoskeletal system is not going to work properly on that day.”
Dr. Silverman comments
I like the idea of looking at the difference between beats instead of the total number of beats. I’d be very interested in seeing how varibilities impact injury rates in sports and other physically intense professions like firefighters, construction workers and mechanics.
The more tools we have to predict cardiovascular events, the better.
Related sources: Medscape, Vilamitjana J, Lentini NA, Perez MF, Verde PE. Heart rate variability as biomarker of training load in professional soccer players. Program and abstracts of the American College of Sports Medicine 2014 Annual Meeting; May 27-31, 2014; Orlando, Florida. Abstract 3069.