In athletes, the ratio between the length of their fingers and their size are linked to the production of lactate, a precious source of energy helping to maintain the effort, during the exercise.
- Lactate is a biological molecule, produced by the muscles and released into the blood circulation. When its levels are high, the body is stressful, which can impact sports performance.
- In a study, lactate levels were low in large women and those whose annular was long compared to the index.
- The effects of prenatal and pubertal sex hormones can play a role in these physical attributes.
A few months from the 2025 women’s Euro, a new study by the University of Swansea (Wales) became interested in professional footballers and at the lactate levels that they produce during the exercise. Lactate is produced by muscles, skin and red blood cells, especially in the event of a lack of oxygen. During a training or intense exercise, more lactate is released in the blood circulation, but high levels may indicate that the body is stressful. This can impact sports performance by limiting the capacity of muscles to contract effectively.
The size, the ratio between the length of the index and the annular, two predictors in women
In research, published in the journal Early Human Developmentthe Welsh team has tried to determine whether it is possible to predict the amount of lactate that a person will produce based on physical attributes, including the length of the fingers and the size. “The lactate and the ratio of the fingers (2D: 4D), that is to say between the length of the index and the annular of a person, have already been linked to cardiovascular disease and certain cancers.” For the needs of the work, scientists have recruited 28 professional football players. They were asked to take a test on a treadmill, the speed of which was at the start of 6 km/h and was increased by 2 km/h every 3.15 min, with measurements at 6, 8, 10, 12 and 14 km/h. During this effort, their lactate levels were evaluated.
In some volunteers, lactate levels increased with racing speed. In detail, the finger ratio (2D: 4D) was not associated with lactate rates between 6 and 12 km/h. “At 14 km/h, the lactate was positive.” Previous studies had suggested that the relationship of the fingers was the strongest predictor of the lactate rate. “For women, there were two predictive factors, the size and the 2D report: 4D.”
“Testosterone-esterogenic balance in the uterus and puberty”
“We think that the link here is the balance testosterone-estrogen in the uterus and puberty.” According to the authors, a long ring finger is a high level marker of prenatal testosterone and a long index is a higher level of prenatal estrogen levels. “Women having experienced a high level of testosterone and a low estrogen rate before birth (long annular) and puberty (large women) produced low lactate rates during the treadmill test. (…) These results have implications beyond football, in sports, such as background race, as well as in clinical contexts where a high rate of lactate is found in medical conditions in medical conditions serious, for example following a heart attack “, concluded the researchers.
