If you find yourself lacking in motivation to hit the gym, attend a fitness class or go for a run, you may want to take a moment to check your fingers...
According to an American study, there is direct correlation between digit length and voluntary exercise. The evidence suggests that the desire to exercise and excel in sports is fixed very early on in life and is related to exposure to prenatal stress hormone levels.
The greater the difference in length of the ring and index finger (with the ring finger being the longer of the two), the more likely you are to possess greater athletic motivation. Having a ring finger longer than your index finger has also been linked to earning a higher salary, being more aggressive and having a lower risk of developing heart disease.
Yan et al, Behavioural Trait Changes Digit Ratio, PLoS ONE, 2008, 3(9): e3216.