Positional Differences in Pre-Season Scrimmage Performance of Division I Collegiate Football Players

Abstract

This study aimed to describe the physical demands of American football players using novel performance analysis techniques. Heart rate (HR) and accelerometer-based activity levels were observed across two pre-season scrimmages in 23 Division I collegiate football players (age: 19 ± 1 y, height: 1.90 ± 0.06 m, weight: 116.2 ± 19.4 kg). Data were analyzed using a MATLAB program and inter-rater reproducibility assessed using inter-class correlations (ICC). Players were analyzed by side (offense/defense) and position (skill/non-skill). Performance variables assessed in bursts of activity included burst duration, HRmean and HRmax (bpm), and mean activity (vector magnitude units [vmu]). Exercise intensity was categorized as time spent in % HRmax in 5% increments. The burst duration (8.1±3.9 min, ICC = 0.72), HRmean (157 ± 12 bpm, ICC = 0.96) and mean activity (0.30 ± 0.05 vmu, ICC = 0.86) were reproducible. HRmean (p = 0.05) and HRmax (p = 0.001) were greater on defense. Offense spent more time at 65–70% HRmax (p = 0.01), 70–75% HRmax (p = 0.02) while defense spent more time 90–95% HRmax and ≥95% HRmax (p = 0.03). HRmean (p = 0.70) and HRpeak (p = 0.80) were not different between positions across both sides. Skilled players demonstrated greater mean activity (p = 0.02). The sport-specific analysis described HR and activity level in a reproducible manner. Automated methods of assessing HR may be useful in training and game time performance but ultimately provides support to coaching decision making.

Physiological and Biomechanical Monitoring in American Football Players: A Scoping Review

“…Most of the papers [ 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 ] dealt with the topic of training loads in American football athletes and all of them measured external loads. Eight papers [ 147 , 153 , 154 , 159 , 164 , 165 , 166 , 168 ] measured internal load.…”

“…Most of the papers [ 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 ] dealt with the topic of training loads in American football athletes and all of them measured external loads. Eight papers [ 147 , 153 , 154 , 159 , 164 , 165 , 166 , 168 ] measured internal load. Investigations of physical demands during practices were reported by five papers [ 144 , 151 , 157 , 163 , 167 ], whereas another five papers focused on game demands [ 145 , 148 , 150 , 158 ].…”

“…In four of the analyzed papers [ 144 , 164 , 166 , 168 ], the internal load measures were extracted from wearable sensors. Another four papers published by Flatt et al, from 2018 to 2021 [ 153 , 154 , 159 , 165 ], opened up a new research line regarding the monitoring of HRV and cardiovascular recovery between training days in American football athletes.…”

“…The second largest branch of research connected with American football involves the monitoring of physiological parameters, workloads, and performances. The main applications are the monitoring of external and internal loads [ 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 ], monitoring of temperature [ 135 , 136 , 137 , 138 , 139 , 140 , 141 , 142 , 143 ] and catch rates [ 124 ]. Heat monitoring was performed in most of the analyses using invasive methods.…”

“…Thus, future research should focus on investigating new non-invasive ways to extract temperature data from athletes during practice and competition, given the fatal outcome of exertional heat illness. Regarding load monitoring, all of the evaluated literature dealt with external workloads, but eight of the analyzed papers [ 147 , 153 , 154 , 159 , 164 , 165 , 166 , 168 ] collected data on internal loads and used wearables to extract heart rate series [ 164 , 166 , 168 ], four of which used portable sensors to monitor heart rate variability [ 153 , 154 , 159 , 165 ], and one considered a perceived exertion questionnaire [ 147 ]. Future research should focus on expanding the use of wearable sensors to monitor heart rate and heart rate variability.…”