The use of sport technology devices is continuing to grow in the field of athletic performance and is starting to trickle down from professional and collegiate levels to high school settings. Specifically, wearable tracking devices are becoming widely used to help optimize training, assess player performance, and evaluate injury risks. Data from these devices can provide insight into how athletes are responding to the stressors placed on them during training, competition and recovery. By evaluating the data, coaches can manipulate training programs and training sessions to meet the needs of the athlete.

Coach First, Data Second

Yes, we can use these devices to help us evaluate our athletes and programs; however, these metrics should be used in combination with our experience and understanding of how our athletes perform. I believe we are coaches and motivators first and data junkies second. We must rely on our coaching experience/eye first and then try to find an appropriate balance between what we observe and metric measurements. In finding that balance, there is certainly a place for these devices to be used but it is important to understand what we are looking for and how it is relevant to our athletes.

Reasons to Monitor Athletes

We use these devices as a way to assess athlete’s physical and physiological states. At the 2018 NSCA Coaches Conference, Ryan Curtis (Korey Stringer Institute) provided the following four main purposes for monitoring athletes: 1) optimize readiness; 2) ensure proper prescription of stress and recovery; 3) reduce injury risk and 4) monitor safe and effective return to play protocols3.



*Curtis, R. Integrating Wearable Technology and Analytics to Maximize Performance. Presentation National Strength and Conditioning Association Coaches Conference, Charlotte, NC., January 2018.

“What Are We Looking For?”— Categorizing the Metrics

These devices provide us with a vast amount of data; thus, understanding which metrics are appropriate to our group of athletes is necessary to assess and track our teams and programs. At the collegiate level, it may be that we work with multiple sport teams each of which may encompass different movement and energy system demands. Therefore, the ability to record and evaluate various measures may help make comparisons between teams and athletes.

Organizing the data into categories, such as workload, readiness / recovery, and performance state is the first step to understanding what we need to analyze. Once we understand what we need to analyze, we can breakdown the information into more manageable segments.

In looking at training load, for example, internal and external stress can be monitored through the use of movement or biometric sensors. Internal stress often refers to physiological or psychological aspects while external stress represents the work or activities performed 1. Internal loads can be represented by cardiovascular/respiratory measures, biochemical, hormonal, immunological markers, or neuromuscular performance. Specific devices can be used to help evaluate the physiological status of the athlete with respect to hydration level, sleep quantity and quality, various heart rate derivatives, etc. Quantifying internal stress may help to better understand how an athlete is responding, enhance personalized training and/or identify potential injury risks or maladaptations1.

External load is evaluated by movement tracking or specific performance levels with devices such as global positioning systems (GPS), accelerometers, or gyroscopes. Wearable devices are becoming more common in a variety of settings as they can provide measures of position, velocity, acceleration, distance, intensity, etc. Accelerometers, for example, can quantify the overall load on an athlete from acceleration, deceleration, change of direction, collision, and impact data. These data can then be used to determine total stress scores during training sessions and competitions1. Utilizing both the internal and external data can be beneficial when looking at how the body is responding to the dose of specific external activities. Due to the endless data these devices can supply, coaches should first understand what measures are relevant and how they may help improve training and perforce.

Baseball and Sport Technology

In looking at the practical use of sport technology in baseball, various metrics can be applied to assist in monitoring progress, workload, and recovery. The workload over the course of a season includes the stresses associated with practice, games, training, throwing, swinging, running, etc., and each can have a significant effect on rest and recovery. Taking this into account, identifying devices that can provide specific metrics to display workload in a manner that helps us look at stress and recovery is key. We may focus on looking at the data in an acute workload to chronic workload ratio over the course of a season as a way to monitor changes in stress and recovery to ensure gradual and safe progress. Analyzing data in an objective manner can help us understand how athletes are responding to and recovering from workloads over the course of a season.

Pitching, for example, is characterized by repeated high-intensity efforts. Thus, with starting pitchers, the ability to monitor status between starts can help to reduce potential overload or overuse within a season. Resting heart rate variability (HRV) is one noninvasive internal load method for monitoring autonomic nervous system (ANS) function. HRV measures can help outline the balance between the parasympathetic and sympathetic systems; thus, describing the load and recovery on the athlete’s ANS2.

In a standard 5-day pitching rotation, for example, the ability to monitor internal load throughout the season may be useful to help ensure a balance between load and recovery. For example, if HRV measures remain low for more than 2 days after a start, it could be an indicator of inadequate recovery and, over a season, may identify pitchers at risk for overuse injury2. A decline in HRV could be the result of normal acute fatigue from their start so, daily measures of HRV can be collected and assessed over a season to more accurately monitor ANS function and recovery2. Comparing acute responses to chronic data may be the best method to accurately gauge the load to recovery state. Most importantly is understanding what is relevant and necessary to track and look for in our athletes so we are not blinded by the endless amount of data thrown our way.

What Measures are Relevant to Us and What Should We Use to Find It?

What we intend to do with the data is dependent on what factors are needed to track performance and programs to effectively and efficiently improve player performance and reduce the risk of injury. Simply looking at what is relevant to our athletes and programs can help to streamline decision making when it comes to training. Because these devices are being used in a variety of strength and conditioning settings, it is essential that coaches obtain information on their use and application in order to help the profession grow.

Category Metrics

  • Workload (Internal/External)
  • Recovery/Fatigue State (Subjective/Objective)
  • Anthropometrics
  • Performance Level (Aerobic/Anaerobic Status)



  1. Cardinale, M., & Varley, M. C. (2017). Wearable training-monitoring technology: applications, challenges, and opportunities. International Journal of Sports Physiology and Performance,12(2), 1-23.
  2. Cornell, D. J., Paxson, J. L., Caplinger, R. A., Seligman, J. R., Davis, N. A., & Ebersole, K. T. (2017). Resting heart rate variability among professional baseball starting pitchers. Journal of Strength & Conditioning Research,31(3), 575-581.
  3. Curtis, R. (2018, January). Integrating Wearable Technology and Analytics to Maximize Performance. Presentation presented at the 2018 National Strength & Conditioning Association Coaches Conference, Charlotte, NC.


Henry Aleck, MS, CSCS is strength and conditioning coach for the Phillies South Atlantic League Lakewood BlueClaws in Lakewood, NJ.



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