While our DNA is determined at conception, researchers reporting in the March issue of Cell Metabolism, say that we can beneficially alter our DNA molecules in a matter of minutes, simply by exercising. Furthermore, caffeine may also offer similar effects.

The research highlighted that, while our underlying genetic code remains the same, exercise does chemically and structurally alter the DNA molecules within our muscles. "Our muscles are really plastic," said Juleen Zierath of Sweden's Karolinska Institutet. "We often say 'You are what you eat'. Well, muscle adapts to what you do. If you don't use it, you lose it, and this is one of the mechanisms that allows that to happen."

The precise DNA changes are known as epigenetic modifications, which are modifications to the genome that do not involve a change in the nucleotide sequence of DNA (A, G T, and C), but result in changes in function by altering the expression of certain genes. In this case, it involves the gain or loss of chemical marks on DNA.

The study revealed that after a burst of exercise, our DNA bears fewer chemical marks (specifically methyl groups) than it did before exercise. The researchers say the changes occur in stretches of DNA that are involved in turning "on" genes important for muscles' adaptation to exercise.

The researchers also witnessed a similar loss of DNA methyl groups when making muscles contract in lab dishes. Surprisingly enough, they also observed the same effect when exposing the muscle to caffeine. Zierath explained that the effect of caffeine classically mimics the muscle contraction that occurs when we exercise.

This doesn't mean we should start drinking jugs of coffee and quit our gym subscription, however mixing the two may prove a worthy result. It is more likely that, however, that the findings could lead to new caffeine-based medicines that provide benefits similar to that of exercise.