Markers of exercise performance between animal species

What is the question?

Mother Nature has some pretty fast, strong and scary animals. Humans actually fall into the category of being the slowest and weakest. If we want to learn about performance, maybe we should study them… if they would allow us.

Species are formed as a result of small genetic differences. Mammals share a number of genes that are similar, with only  very small differences in their genetic code. Comparatively, there are vast differences between land mammals on a morphological level. These include size, stature, muscle mass and limb length, to name but a few. But, given the vast number of animal species, their muscles are very poorly studied – only 0.9% of the 5500 mammal species have been studied on a muscular level.

What has been found so far?

The Myolab has already made some significant headway in studying muscle contractility, metabolism and structure of some African wildlife species. For starters, the cat species (lion, caracal and cheetah) have more than 50% type IIX muscle fibres, whereas the same muscle in humans contain between 5 – 20%. The prey of these wild cats, that includes the springbok, kudu, mountain reedbuck, blesbok and fallow deer, also has more than 50% type IIX fibres.

The type IIX  fibres are very strong in comparison to the human equivalent. In fact, one type IIX single fibre from either the caracal or lion can produce three times the amount of power that the human equivalent! To produce this exceptional power, these animals must rely on efficient and an abundance of ATP generated from their muscle metabolism. Collectively, the cats and antelopes have a very high capacity to burn carbohydrates in the form of glycogen and blood glucose. However, this is where the prey has the advantage: they all have many more mitochondria in their muscle whereas the cats have very little.  In essence, the prey have speed and endurance whereas the cats only have speed. These findings confirm why cats need to stalk their prey and kill quickly. Once the antelope gets away and starts running, the odds of catching it becomes very poor.

Future directions?

We are very fortunate to have a number of wildlife veterinarians forming part of this study and many species samples have since been collected. Thus, watch this space.

If you are interested in pursuing an MSc or PhD in this field, please contact the MyoLab.