I have posted a series of blogs on the muscle-to-bone ratio (MBR) in both National League Football (NFL) players and NCAA Division I College Football Players. One series of blogs focused on NFL players and compared their total as well as regional MBRs to a group of healthy age-matched males, while a second blog examined the MBR in NFL players by position. Both blogs were from research conducted in my laboratory that focused on total-body as well as regional (i.e., arm, leg, trunk) MBRs in NFL players [Dengel et al., 2023]. Another series of blogs focused on college football players and compared their total and regional MBRs to a group of healthy age-matched males. In addition, a second blog examined the total as well as regional MBRs in college football players by position. The data used in these blogs on college football players was also from research conducted by my laboratory [Dengel et al., 2024].
Since we have data on both NFL (n=346) and college football players (n=553), I thought it would be interesting to compare the total as well as regional MBRs in these two unique but different football populations. It is important to remember that the NFL players were older than the college football players 24.2+2.6 vs 20.1+1.5 yrs, p<0.0001) and thus will have had more time to develop their muscle and bone masses, etc. In these next few blog postings, I will compare total as well as regional MBRs in NFL and college football players. Subsequent blogs will look at the various positions and compare the different position groups of these two football populations.
Although the NFL players were taller (187.2+5.4 vs 186.1+6.7 cm, p<0.01) than the college football players, they were not heavier (109.0+18.7 vs. 106.8+21.3 kgs, p=0.11) (Figure 1, below) nor was a difference in the body mass index (BMI: 31.0+4.5 vs. 30.6+5.0 kg/m2, p=0.23) between the two groups. Looking at Figure 1 below you will notice that although there was not a significant difference in total mass (109.0+18.7 vs. 106.8+21.3 kg, p=0.1149) between NFL and college football players. However, the NFL players had significantly greater amounts of lean mass (84.6+8.8 vs. 80.1+10.0 kg, p<0.0001) and fat mass (19.8+1.3 vs. 22.2+12.5 kg, p=0.0003) than the college football players. The NFL players also had a greater amount of bone mass (4.6+0.5 vs. 4.3+0.5 kg, p<0.0001) than the college football players. However, it should be noted that there was no difference in bone mineral density (1.61+0.11 vs. 1.60+0.12 g/cm2, p=0.298) between the two groups. The similar total mass, but significantly lower amounts of lean and bone masses in the college football players explains their greater percentage fat when compared to NFL players (17.9+6.9 vs.19.6+6.7%, p=0.007).
Now let us compare the total and regional MBRs between college football and the NFL players. The NFL players had a greater total MBR (19.12+1.88 vs 17.30+1.50, p<0.00001), but a significantly lower arm MBR (16.48+1.88 vs. 18.60+1.40, p<0.00001) than the college football players (Figure 2). The NFL players also had a greater trunk MBR (31.56+4.19 vs. 26.70+2.70, p<0.00001)(Figure 2) than the college football players. Finally, there was no difference in leg MBR between NFL and college football players (16.85+1.87 vs. 17.00+1.80, p=0.2314).
There are two possible explanations for the greater total and regional MBRs in the NFL compared to college football players. One explanation may be the fact that overall; the NFL players had a greater amount of muscle mass than the college football players. In addition, the NFL players also had a greater amount of bone mass (@0.3 kg more) than the college football players. However, the greater difference in muscle mass (@4.5 kg more) powered the significant difference in MBR between the two groups. The greater trunk MBR may also be explained by the greater muscle mass in the trunk region in the NFL compared to college football players. Another possible explanation for the results may be the large number of offensive linemen in the college football players group compared to the NFL players group. The college football player group consisted of 23% offensive linemen (n=125) while the NFL player group consisted of only 11% offensive linemen (n=38). As we have pointed out in another blog (https://www.dexalytics.com/news/normative-data-football-offense/) offensive linemen have a higher percentage of body fat than the other position groups. It is possible that this greater percentage of offensive linemen in the college football player group could have skewed the results to some degree. Therefore, it might be better to look at the data from these two groups by position. Given the large number of athletes examined in these two studies [Dengel et al., 2023; Dengel et al., 2024] this would be possible. So, in the next series of blogs, we will compare NFL and college football players by position groups to see if these differences still exist.
What does it all mean?
First, the research used in this blog about NFL [Dengel et al., 2023] and college football [Dengel et al., 2024] adds to our overall knowledge about MBR and athletics. It is possible that the MBR will give coaches and athletic trainers another matrix to monitor the effects of various training programs on muscle and bone, as well as the relationship between the two tissues. Our next blog will examine positional differences between NFL and college football players in total as well as regional MBR.
REFERENCES
Dengel DR, Evanoff NG. Positional differences in muscle-to-bone ratio in National Football League Players. International Journal of Sports Medicine 44:720-727, 2023.
Dengel DR, Studee HR, Juckett WT, Bosch TA, Carbuhn AF, Stanforth PR, Evanoff NG: Muscle-to-bone ratio in NCAA division I collegiate football players by position. Journal of Strength and Conditioning Research 38(9): 1607-1612, 2024.
About the Author
Donald Dengel, Ph.D., is a Professor in the School of Kinesiology at the University of Minnesota and is a co-founder of Dexalytics. He serves as the Director of the Laboratory of Integrative Human Physiology, which provides clinical vascular, metabolic, exercise and body composition testing for researchers across the University of Minnesota.