|
 
 |
| LETTER TO EDITOR |
|
| Year : 2021 | Volume
: 21
| Issue : 1 | Page : 33-34 |
|
Low 2D: 4D may reduce the use of doping in sports
Muhammad Shahidul Islam
Office of Physical Education, Shahjalal University of Science and Technology, Sylhet, Bangladesh
| Date of Submission | 22-Mar-2021 |
| Date of Acceptance | 03-Apr-2021 |
| Date of Web Publication | 07-Jun-2021 |
Correspondence Address:
Muhammad Shahidul Islam
Shahjalal University of Science and Technology, Sylhet
Bangladesh
  | Check |
DOI: 10.4103/sjsm.sjsm_9_21 
How to cite this article:
Islam MS. Low 2D: 4D may reduce the use of doping in sports. Saudi J Sports Med 2021;21:33-4 |
Dear Editor,
The length of the index finger in relation to the length of the ring finger (2D: 4D) of a palm is thought to be a potential biomarker of prenatal androgen exposure.[1] This finger length ratio of 2D: 4D at the end of the first trimester of gestation (week 1 to week 12 of pregnancy) is also a possible pointer of prenatal testosterone and prenatal estrogen hormone balance. There-after, the prenatal hormonal balance defined by digit ratio (2D: 4D) probably remains unchanged significantly throughout life.[2],[3],[4] On the other hand, the gender difference in digit length ratios has been linked to utero androgen to estrogen balance.[5] The 2D: 4D is sexually dimorphic, with men's second digit (index finger) being shorter than the fourth digit (ring finger) and the length difference between the two digits being greater than women's.[3],[6] However, female athletes have a greater finger length difference of 2D: 4D as their ring finger becomes longer than the index finger and their digit ratio becomes low.[7],[8] According to early research, prenatal androgen exposure, the most significant androgen, is needed for mammalian brain sexual differentiation, which has long-term consequences for games, sports, physical activity, and competitive behavior.[9],[10],[11],[12],[13],[14],[15],[16] Since the lower digit ratio (high prenatal androgens) was expected to influence the performance of soccer, surfing, sprinting, endurance, hand-grip strength, rowing, kabaddi, swimming, tennis, and other sports.[6],[7],[10],[14],[16],[17],[18],[19],[20],[21],[22],[23] A fetus exposed to more testosterone is expected to have a lower digit ratio (masculine ratio). Given the fact, male fetuses are subjected to more testosterone than female fetuses and males often have lower digit ratios than females.[24] Female elite athletes, on the other hand, have lower 2D: 4D values than female nonathletes, which is an interesting finding.[25],[26],[27] Previous research has shown that men and women with higher, more feminized 2D: 4D ratios are more likely to suffer from depression and anxiety than those with lower, more masculine 2D: 4D ratios.[28]
Doping agents have banned substances widely used in competitive sport, especially among female athletes, and are used by both nonelite and elite athletes to improve athletic performance. Female athletes with high or extremely high androgen levels (whether endogenous or exogenous) have a competitive advantage of 2%–5% over those with androgen levels below the standard female range in some sports.[29] According to the study, athletes with higher serum testosterone concentrations had a competitive advantage over those with testosterone levels in the normal female range. As a result, increased endogenous androgens can boost physical performance.[30] Therefore, a digit ratio test could be used to select female athletes, which could be an important factor in preventing doping in women's sports in the future. In the field of sports, the 2D: 4D, when combined with other physical and physiological tests, can be an important discriminator in recognizing young talent. Since a low digit ratio possibly confirms high androgen exposure in prenatal life, it may help to minimize the use of doping in sports.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | |  |
| 1. | Bönte W, Procher VD, Urbig D, Voracek M. Digit ratio (2D: 4D) predicts self-reported measures of general competitiveness, but not behavior in economic experiments. Front Behav Neurosci 2017;11:238.  |
| 2. | Manning JT, Scutt D, Wilson J, Lewis-Jones DI. The ratio of 2 nd to 4 th digit length: A predictor of sperm numbers and concentrations of testosterone, luteinizing hormone and oestrogen. Hum Reprod 1998;13:3000-4. |
| 3. | Manning J, Kilduff L, Cook C, Crewther B, Fink B. Digit ratio (2D: 4D): A biomarker for prenatal sex steroids and adult sex steroids in challenge situations. Front Endocrinol 2014;5:9. |
| 4. | Garn SM, Burdi AR, Babler WJ, Stinson S. Early prenatal attainment of adult metacarpal-phalangeal rankings and proportions. Am J Phys Anthropol 1975;43:327-32. |
| 5. | de Sanctis V, Soliman AT, Elsedfy H, Soliman N, Elalaily R, Di Maio S. Is the second to fourth digit ratio (2D: 4D) a biomarker of sex-steroids activity? Pediatr Endocrinol Rev 2017;14:378-86. |
| 6. | Manning JT, Churchill AJ, Peters M. The effects of sex, ethnicity, and sexual orientation on self-measured digit ratio (2D: 4D). Arch Sex Behav 2007;36:223-33. |
| 7. | Longman D, Stock JT, Wells JC. Digit ratio (2D: 4D) and rowing ergometer performance in males and females. Am J Phys Anthropol 2011;144:337-41. |
| 8. | Manning JT. Digit Ratio (A pointer to Fertility, Behavior, and Health). United States of America: Rutgers University Press; 2002. p. 140. |
| 9. | Manning JT, Baron-Cohen S, Wheelwright S, Sanders G. The 2 nd to 4 th digit ratio and autism. Dev Med Child Neurol 2001;43:160-4. |
| 10. | Manning JT, Taylor RP. Second to fourth digit ratio and male ability in sport: Implications for sexual selection in humans. Evol Hum Behav 2001;22:61-9. |
| 11. | Acar H, Tutkun E. Analysis of the 2D: 4D ratios of national and amateur football players. Int J Appl Exerc Physiol 2019;8:132-7. |
| 12. | Keshavarz M, Bayati M, Farzad B, Dakhili A, Agha-Alinejad H. The second to fourth digit ratio in elite and non-elite greco-roman wrestlers. J Hum Kinet 2017;60:145-51. |
| 13. | Moffit DM, Swanik CB. The association between athleticism, prenatal testosterone, and finger length. J Strength Cond Res 2011;25:1085-8. |
| 14. | Islam MS, Kundu B. Digit ratio and soccer. Orthop Sports Med Open Access J 2019;3:227-30. |
| 15. | Perciavalle V, Di Corrado D, Petralia MC, Gurrisi L, Massimino S, Coco M. The second-to-fourth digit ratio correlates with aggressive behavior in professional soccer players. Mol Med Rep 2013;7:1733-8. |
| 16. | Hsu CC, Su B, Kan NW, Lai SL, Fong TH, Chi CP, et al. Elite collegiate tennis athletes have lower 2D: 4D ratios than those of nonathlete controls. J Strength Cond Res 2015;29:822-5. |
| 17. | Hone LS, McCullough ME. 2D: 4D ratios predict hand grip strength (but not hand grip endurance) in men (but not in women). Evol Hum Behav 2012;33:780-9. |
| 18. | Manning JT, Hill MR. Digit ratio (2D: 4D) and sprinting speed in boys. Am J Hum Biol 2009;21:210-3. |
| 19. | Sudhakar HH, Majumdar P, Umesh V, Panda K. Second to fourth digit ratio is a predictor of sporting ability in elite Indian male Kabaddi players. Asian J Sports Med 2014;5:e23073. |
| 20. | Sudhakar HH, Veena UB, Tejaswi RN. Digit ratio (2D: 4D) and performance in Indian swimmers. Indian J Physiol Pharmacol 2013;57:72-6. |
| 21. | Kim TB, Kim KH. Why is digit ratio correlated to sports performance? J Exerc Rehabil 2016;12:515-9. |
| 22. | Islam MS, Kundu B. Soccer passing accuracy differentiates between high and low digit ratio (2D: 4D) soccer players. Am J Sports Sci 2020;8:49-55. |
| 23. | Islam MS, Kundu B. Low digit ratio (2D: 4D) and masculine attributes: A critical analysis. Int J Res Granthaalayah 2020;8:384-90. |
| 24. | Jeevanandam S, Muthu PK. 2D: 4D ratio and its implications in medicine. J Clin Diagn Res 2016;10:CM01-3. |
| 25. | Giffin NA, Kennedy RM, Jones ME, Barber CA. Varsity athletes have lower 2D: 4D ratios than other university students. J Sports Sci 2012;30:135-8. |
| 26. | Lombardo MP, Otieno S, Heiss A. College-aged women in the United States that play overhand throwing sports have masculine digit ratios. PLoS One 2018;13:e0203685. |
| 27. | Eklund E, Ekström L, Thörngren JO, Ericsson M, Berglund B, Hirschberg AL. Digit ratio (2D: 4D) and physical performance in female olympic athletes. Front Endocrinol (Lausanne) 2020;11:292. |
| 28. | Bailey AA, Hurd PL. Depression in men is associated with more feminine finger length ratios. Personal Individ Differ 2005;39:829-36. |
| 29. | Bermon S. Androgens and athletic performance of elite female athletes. Curr Opin Endocrinol Diabetes Obes 2017;24:246-51. |
| 30. | Huang G, Basaria S. Do anabolic-androgenic steroids have performance-enhancing effects in female athletes? Mol Cell Endocrinol 2018;464:56-64. |
|
Search Pubmed for