Posted by 
My steam project consists of a clay art project of muscle fibers between athletes versus lions. My objectives covered in this project include comparing and contrasting skeletal, cardiac, and smooth muscle, and relate the interaction of muscles and the skeletal system. Because this project is about muscle fibers, I did not compare cardiac and smooth muscle because I was focusing on the skeletal muscle. Skeletal muscles contain type I (slow twitch) and type II (Fast twitch) fibers. Muscles are attached to the skeleton via tendons. When forcefully moving, both athletes and lions use their fast glycolytic fibers. The skeleton gives the muscle this ability to move, whether it’s slow or quick movements. Here in this project you can see the differences in the muscle fibers. The human muscle fibers show more space and rounder fibers. The lion’s fibers are more compact and less round. This visual really helps see the difference in how athletes and lions use their fast glycolytic fibers.
Different muscle fibers in athletes consist of fast oxidative, slow oxidative, and fast glycolytic fibers. Now endurance athletes have increased oxidative fibers while power and sprinting athletes have a lot more fast glycolytic fibers. (S. S. Missinaa, *, A. S. Kriuchkova , M. A. Dikunetsa, and E. B. Myakinchenkoa, 2022) There have been multiple tests run on these different athletes and have concluded that long-term training for endurance increases not only the oxidative capacity of muscle fibers, but also type I muscle fibers in the cross-sectional areas relative to that in strength athletes and speed strength athletes and type II muscle fibers cross-sectional area relative to that in speed strength athletes. (Hall et al., 2021) Endurance athletes do not produce as much fast twitch muscle fibers as power athletes. Slow twitch fibers percentage have been related to age in endurance athletes with no relationship to power athletes.
Lions have type I and type IIx fibers, also known as fast twitch fibers. These are the powerful glycolytic fibers lions predominantly use. Lions produce more type II fibers than athletes and a significant amount of more force than athletes. (Tertius A. Kohn, Timothy D. Noakes, 2013)Most significantly, the maximum power of lion type IIx fibers was 2.6 times greater than that of athlete type IIx fibers. (Tertius A. Kohn, Timothy D. Noakes, 2013) The type IIx fibers from both caracal and lion produced less absolute force compared with athlete type IIa and type IIx fibers from body builders. Lion and caracal type IIx fibers were 1.6× and 2.1× larger, respectively, than the remainder of their fiber types. (Tertius A. Kohn, Timothy D. Noakes, 2013) The athlete types I and IIa fibers were larger than their IIx fibers.
In this piece, it shows a clay art project that compares two different muscle fibers between athletes and lions. Lions have a higher proportion of fast twitch muscle fibers than athletes, which is why these fibers need to be so closely compact. They are a lot more active in Lions than athletes which is why they need to be so much closer together. In the athlete muscle fiber, you can see there are also few muscle fibers and contain more space than the lion’s muscle fiber. Because of the strength of the lion’s type IIx, this requires them to be more compact with little space.
Another animal with similar muscle fibers as a lion is caracal and felids. A clear distinction between the athlete and feline muscles was the predominance of type IIx and low proportions of types I and IIa fibers in the latter, whereas types I and IIa fibers were more predominant in athletes This is consistent with previous studies on felids and human endurance runners. ( Tertius Abraham Kohn a et al, 2011)
Overall, lions have a lot more type IIx fibers than athletes and give lions the powerful strength they need in order to survive. Athletes use more type I and type IIa than lions but can still produce type IIx for power and speed athletes.
References:
- ( Tertius Abraham Kohn a et al., Fiber type and metabolic characteristics of lion (Panthera leo), caracal (caracal caracal) and human skeletal muscle 2011)
- (Hall et al., Association of muscle fiber composition with health and exercise-related traits in athletes and untrained subjects 2021)
- (Tertius A. Kohn, Timothy D. Noakes Lion (Panthera leo) and caracal (caracal caracal) type IIX single muscle fibre force and power exceed that of trained humans | journal of experimental biology | the company of Biologists 2013) Peer Reviewed
- (S. S. Missinaa, *, A. S. Kriuchkova , M. A. Dikunetsa, and E. B. Myakinchenkoa, Cross-Sectional Areas of Various Muscle Fibers in Skeletal Muscles of Athletes Training for Endurance, Strength, or Speed-Strength 2022) Peer Reviewed