Indeed, the enzyme markers involved in anaerobic metabolism of these fuels (CK, LDH and PHOS) in the felids were all significantly higher than human, yet lower than cheetah (LDH only), thus agreeing with their preferred activity and hunting strategy. However, an unexpected finding was the low PFK activity in both felids. Being a major rate-limiting enzyme of glycolysis and that these animals probably would rely on anaerobic metabolism due to their nature of being fast sprinters, the opposite was expected. Although low activities of PFK were found in bovine and Rhesus monkeys, comparisons of PFK activities to other fast sprinting species are unfortunately limited and would have revealed more insight into their metabolism