Determining Clinically Relevant Measures for Evaluating Recovery in Collegiate Athletes using Heart Rate Variability and RESTQ-Sport

Abstract

Introduction: Effective training involves the accumulation physical stresses in an effort to produce overload and effect physiological change. The ability to quantify the balance of training stress and recovery on an individual basis is lacking, as is the ability to identify athletes who are not fully recovered in order to make changes earlier in their training. Evaluating recovery on a regular basis has the advantage of indicating an increased need for rest prior to performance declines allowing the athlete to resume normal training and competition following a brief respite. The method of collecting this data should be easy and readily available to the athlete, be validated against existing methods and allow for changes that are clinically relevant even if they are not statistically significant. Four separate studies were used to evaluate recovery methods in Collegiate Student athletes using subjective and objective measures. Methods: Heart rate variability was assessed using traditional ECG methods of data collection as well as with photoplethysmography using the flash form a smartphone and a smartphone application. Subjective stress levels were assessed using the RESTQ-Sport and evaluation of training load, the product of minutes trained times RPE. Conclusions: While time domain and frequency domain measures cannot be used interchangeably, the HF power of AR is an acceptable alternative to RMSSD, the preferred time domain measure. There is a clear curvilinear relationship between HRV measures and stress in collegiate athlete however there is not one measure that best associates to any one RESTQ-Sport scale. The use of a smartphone application is acceptable for evaluating the time domain measures of HRV but not the frequency domain measures as the application uses different methods of calculation. The RR intervals obtained from the smartphone can be assessed using Kubios HRV software in order to determine HRV measures. The SRM is an appropriate statistical measure for evaluating change in daily HRV measures for collegiate football players. The 0.5 SD of change appears too conservative of a measure to evaluate change and a 90% CI is more appropriate, especially in athletes who primarily undergo anaerobic training.