New research examines how position and injury affect heart rate variability in NCAA football players during preseason training
As college football players push through the intense demands of preseason training, new research from Georgia Southern University suggests that the body’s response to those workloads may vary depending on an athlete’s position on the field.
A recent study published in the International Journal of Sports Physiology and Performance examined how physical workload during preseason camp relates to heart-rate variability (HRV) in NCAA Division I football players. The research was led by Andrew Flatt, Ph.D., associate professor in Georgia Southern’s Department of Health Sciences and Kinesiology in the Waters College of Health Professions, along with collaborators from the University of Alabama, John Allen, M.Ed., Clay Keith and Michael Esco, Ph.D.
HRV measures the variation in time between heartbeats and is commonly used by sports scientists to understand how the body responds to physical stress. When HRV remains relatively stable from day to day, it signals that an athlete is adapting well to increased training loads.
To explore how different athletes respond during the demanding preseason period, researchers followed 27 players from a Division I national championship-winning program. They monitored both training workload and HRV to determine how the two were related across different position groups.
The study found that players responded differently depending on their role on the field.
Skill position athletes, including wide receivers and defensive backs, tended to show more stable heart-rate patterns as their workloads increased. These players are typically smaller and more aerobically conditioned, which may help them better tolerate the intense running demands and heat of preseason camp.
In contrast, hybrid positions requiring highly versatile skills, such as linebackers, running backs and tight ends, who experienced the highest workloads, showed greater day-to-day fluctuations in HRV. Because these athletes are often larger and may have lower aerobic fitness levels, the researchers suggest they could experience greater cardiovascular strain and dehydration during intense training in hot conditions.
The findings point to players in hybrid positions benefitting from more moderate total workloads to reduce excessive fatigue and improve preseason camp recovery rates.
The research team also examined whether injuries influenced HRV responses. Players were categorized as either “full go,” meaning they could participate without limitations, or “go as can,” meaning they were practicing while managing minor injuries.
While these minor injuries did not appear to significantly reduce on-field workload, they did affect physiological recovery. Players in the “go as can” group showed moderately lower HRV levels than their fully healthy teammates, suggesting that even minor injuries can place additional stress on the body.
For coaches and sports performance staff, the study highlights the importance of monitoring how athletes respond to training loads. Rather than considering HRV scores alone, researchers suggest monitoring daily changes, which may provide a better indicator of fatigue or recovery challenges.
The findings also reinforce the value of customized training strategies. By tracking how athletes’ cardiovascular systems respond to fitness routines, teams can better personalize recovery and training plans to keep players at their best throughout the season.