Thursday, January 17, 2008

Football's Southern Exposure

PJR1 and RUbytheshore


Look at where many of the best football players in the country come from: California, Texas, and Florida. Those three, by far, are the best states at producing football players for college football on the Division 1-A level in both quantity and quality. This also holds true for producing football players in the National Football League. Not only are these three states the best at producing players for the collegiate level, they’re well ahead of the fourth and fifth best states, Ohio and Georgia.

Many will ask why this is so. Several factors weigh into this. Population is one. In addition, the level of interest and increased practice time, such as having spring football, are also important. One common thread these three states have is a warmer climate.

A warmer climate allows kids to play outdoors more often than kids in a cooler climate. When kids are outdoors more often, they participate in recreational activities, including athletics. They’re more likely to be outdoors twelve months a year than many other states. The other states may have as many as six months where kids are more likely to stay inside.

Being outdoors more often in a warmer climate can allow athletic skills to develop more rapidly than being in a colder climate where kids aren’t as likely to be competing outdoors as often. Being outdoors also exposes kids to the Vitamin D producing sunshine which is a potent source of natural steroid hormones that may boost athletic performance.

Which States Produce the Most Division 1A Football Players?

Rutgers Rivals football message board poster, PJR1, checked the current rosters of all 117 Division 1A football teams to evaluate which states produce the most football players. The results show that the big southern states of California, Texas and Florida are well above average in terms of sheer numbers, each having produced well over 1200 players per state, The mid-west is also well represented in the top 10, including Ohio with 690, Pennsylvania with 374, Illinois with 343 and Michigan at 338. New Jersey comes in 13th with 241 players while New York is in the top 20 with 167 players.

Some of the mid-west’s relatively large showing may be due to the popularity of the Big 10 Conference and a second regional Mid America Conference (MAC) which is centered in the mid-west. In contrast, the east has fewer 1A programs and eastern athletes may be more likely to wind up in Division 1AA schools and therefore excluded from our count. The count does not differentiate between scholarship athletes and “walk-on” athletes, nor does it distinguish between the skill levels of the players on individual team rosters (e.g. starters, backups and practice squad).

The ranking changes somewhat when normalized by the number of Division 1A athletes per million residents in each state. This gives equal weight to geographically smaller and less populated states. On a per capita basis, Hawaii comes in first by wide margin with 104 athletes per million. Louisiana moves to second place and Florida slips to third while California drops all the way to 15th place.

At the other end of the spectrum, the northern and northeastern states produce the fewest Division 1A football players with Vermont and North Dakota having each contributed no athletes to the rosters of major football programs. Perhaps the athletes in these particular northern states are more interested in hockey and lacrosse. New York, Massachusetts and Connecticut also produce relatively few top football players on a population adjusted basis even though they have extensive high school football programs.

Sunshine and Vitamin D.

According to Dr. John Cannell (1) of the Vitamin D Council, most people are deficient in Vitamin D. Since the Industrial Age began, we have had a tendency to live and work indoors, and more recently have been encouraged by the medical authorities to avoid the sun for fear of skin damage, cataracts and even skin cancer. However, by avoiding the sun we decrease the production of Vitamin D which is primarily produced in the skin when it is exposed to the ultra violet rays in sunshine.

Vitamin D has been shown to be vital to good health and chronic deficiencies have been linked to poor bone health and higher risk for major diseases such as cancer, multiple sclerosis, diabetes and depression. For athletes, Vitamin D is thought to affect athletic performance primarily because it plays a key role in the body’s production of a very potent steroid hormone, calcitriol. As Dr. Cannell suggests:

... peak athletic performance also depends upon the neuromuscular cells in your body and brain having unfettered access to the steroid hormone, activated vitamin D. How much activated vitamin D is available to your brain, muscle, and nerves depends on the amount of 25-hydroxyvitamin D in your blood. In turn, how much 25-hydroxyvitamin D is in your blood depends on how much vitamin D you put in your mouth or how often you expose your skin to UVB light.

Florida, Texas and California, well known as fertile recruiting grounds for major college football programs, are sunny states. Hawaii has an extremely warm and sunny climate. If Vitamin D is a key factor in the production of top tier football players, there should be a correlation between the number of athletes on Division 1A football teams and the levels of Vitamin D producing Ultra Violet (UV) radiation in the states where they come from.

The UV Index (2) is a forecast of the amount of UV radiation expected to reach the earth's surface at the time when the sun is highest in the sky (solar noon). The amount of UV radiation reaching the surface is primarily related to the elevation of the sun in the sky, the amount of ozone in the stratosphere, and the amount of clouds present. The UV Index can range from 0 at night time to 12 or 13 (in Miami or Hawaii under clear skies). Tropical areas with high altitude can have even greater UV Index predictions, though those areas do not occur in the United States. We use the UV Index as a measure of the potential for sun exposure and Vitamin D production. For example, Table 1 summarizes the number of days the UV Index Forecasts in 2006 fell into a certain range for Honolulu, Hawaii and Burlington, Vermont at opposite extremes of the sunshine intensity spectrum.

UV Index Range Honolulu, Hawaii
(Days per Year)
Burlington, Vermont
(Days per Year)
Extreme > 11 115 0
Very High 8-11 115 19
High 6-8 91 52
Moderate 3-6 30 76
Low < 3 6 210

Table 1: UV Index Range for Hawaii and Vermont (Days per Year).

Correlation of the UV Index with D1A Football Players per Capita

Table 2 presents the data for three cases of the UV Index within each state: a) Low (< 3); b) Moderate (3-6); and c) High to Extreme (> 6). We find a substantial correlation (R-squared = 0.56 in Figure 1) between the number of Division 1A football players and days per year having High to Extreme UV Index within the state. We also find a substantial negative correlation (R-squared = 0.49 in Figure 2) between the number of Division 1A football players and days per year having Low UV Index. Between these extremes the number of Division 1A football players is not correlated (R-squared = 0.0017) with days per year having Moderate UV Index.

Figure 1. Positive Correlation: Div !A Football Players with High UV Index.

Figure 2. Negative Correlation: Div !A Football Players with Low UV Index.

We also find a correlation of the Rivals Recruit Data Base (3) by state with the UV Index. Specifically we determined the number of 3, 4 and 5 star rated recruits per million population within a state and correlate this with the number of days per year with UV Index levels in a particular range. The new recruits represent new prospective players who are currently seniors in high school. We find a positive correlation (R-squared = 0.52) of the number of highly rated recruits by state per million capita with the number of days per year with UV Index rated higher than 8. We also find a negative correlation (R-squared = 0.50) of number of athletes per million with number of low (< 3) UV Index days per year.


Southern states do produce more top tier football players per capita than northern states. The reasons for this appear to include greater opportunity to practice outdoors in spring as well as fall. Greater opportunity for being outdoors also enables greater sun exposure and Vitamin D production. The number of 1A quality level football players produced from each state is positively correlated with the number of days per year with high UV Index (greater than 6) and associated high levels of Vitamin D production. The number of athletes is negatively correlated with number of days per year with low UV Index (less than 3). While this correlation could be due to a variety of factors, it supports Dr. Cannell's view that Vitamin D levels may be a significant factor in athletic performance.

The potential benefits of sunlight and Vitamin D for athletic performance suggests that individuals should consider being tested for Vitamin D to determine whether or not they are below optimal levels. Vitamin D levels can also be boosted either with diet or supplements. For example, oily fish such as wild Alaskan salmon is a good source of natural Vitamin D. However, care should be exercised with supplements. As Dr. Cannell advises:

A word of caution, though.. studies suggest that taking too much vitamin D (more than 5,000 IU/day) may actually worsen athletic performance. So take the right amount, not all you can swallow. Take enough to keep your 25_hydroxyvitamin D levels around 50 ng/mL, year_round. Easier yet, regularly use the sun in the summer and a sunbed (once a week should be about right) in the winter—with care not to burn.


1. Dr. John A. Cannell, “Peak Athletic Performance and Vitamin D” The Vitamin D Newsletter, March 2007
2. National Weather Service, Climate Prediction Center
3. Rivals Recruiting Data Base

State (City UV Index) # Div 1A Football Players per Million UVI < 3 (Days/Year) 3 < UVI < 6 (Days/Year) UVI > 6 (Days/Year)
1. Hawaii (Honolulu) 133 104 6 30 321
2. Louisiana (New Orleans) 358 83 44 97 216
3. Florida (Tampa) 1212 66 19 99 239
4. Ohio (Cleveland) 690 60 172 84 101
5. Alabama (Mobile) 275 59 46 104 207
6. Georgia (Atlanta) 511 54 85 99 173
7. Mississippi (Jackson)) 152 52 61 104 192
8. Texas (Dallas) 1226 51 76 98 183
9. Nebraska (Omaha) 87 49 151 90 116
10. Wyoming (Cheyenne) 25 48 113 95 149
11. Kansas (Wichita) 118 43 127 94 136
12. Arkansas (Little Rock) 120 42 109 75 173
13. Colorado (Denver) 194 40 104 91 162
14. Nevada (Las Vegas) 102 40 69 112 176
15. California (Los Angeles) 1380 38 43 123 191
16. Iowa (De Moines) 112 37 159 87 111
17. Oklahoma (Oklahoma City) 132 36 103 84 170
18. Utah (Salt Lake City) 96 36 111 88 158
19. Michigan (Detroit) 338 34 185 74 98
20. South Carolina (Charleston) 147 33 67 106 184
21. Virginia (Norfolk) 247 32 123 90 144
22. New Mexico (Albuquerque) 60 30 43 104 210
23. Pennsylvania (Pittsburgh) 374 30 173 71 113
24. Indiana (Indianapolis) 190 30 158 88 111
25. Tennessee (Memphis) 174 28 120 85 152
26. North Carolina (Raleigh) 254 28 114 91 152
27. New Jersey (Atlantic City) 241 28 149 90 118
28. Washington (Seattle) 179 28 182 86 89
29. Idaho (Boise) 41 27 131 95 131
30. Maryland (Baltimore) 151 27 147 81 129
31. Illinois (Chicago) 343 27 169 83 105
32. Missouri (St. Louis) 148 25 145 87 125
33. Kentucky (Louisville) 106 25 149 86 122
34. Arizona (Pheonix) 158 25 38 114 205
35. Oregon (Portland) 84 22 185 63 109
36. Alaska (Anchorage) 13 19 266 91 0
37. Wisconsin (Milwaukee) 103 18 167 89 101
38. Minnesota (Minneapolis) 95 18 176 87 94
39. Connecticut (Hartford) 60 17 182 80 95
40. West Virginia (Charleston) 25 14 161 86 110
41. Delaware (Dover) 8 9 152 85 120
42. Massachusetts (Boston) 58 9 167 88 102
43. New York (New York) 167 9 158 96 103
44. Montana (Billings) 6 6 150 83 124
45. South Dakota (Sioux Falls) 4 5 169 78 110
46. Rhode Island (Providence) 5 5 179 78 100
47. New Hampshire (Concord) 5 4 182 86 89
48. Maine (Portland) 1 1 179 92 86
49. North Dakota (Bismark) 0 0 176 86 95
50. Vermont (Burlington) 0 0 210 76 71

Table 2: Division 1A Football Players Per State.

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