Skeletal Muscle Phenotype and Performance of an …...athletes muscle characteristics at the cellular level. The purpose of this study was to determine the myocellular phenotype [fiber

ABSTRACT

Purpose: Mixed martial arts (MMA) requires a unique combination of muscular

strength, power, and endurance. However, little is known regarding elite MMA

athletes muscle characteristics at the cellular level. The purpose of this study was

to determine the myocellular phenotype [fiber type, size, and myonuclear domain

(MND) size] and whole muscle performance of an elite MMA fighter. Methods:

One male MMA athlete [Record: 8 wins, 2 losses; Ranked: top 10 in the Ultimate

Fighting Championship (UFC) Light Heavyweight Division] volunteered to

participate in this study [Age: 33 y, Height: 1.89 m, Mass: 102.1 kg (competes at

93.0 kg)]. The participant underwent a vastus lateralis muscle biopsy to analyze

myocellular characteristics, which included myosin heavy chain (MHC) fiber type

distribution (via SDS-PAGE), fiber size (cross-sectional area; CSA), and MND size

(via immunofluorescent labeling and confocal microscopy). Whole muscle

performance measures included hand grip dynamometry, peak isometric mid-thigh

pulls, vertical jump (measured with no counter-movement), and 5 repeat Wingate

Anaerobic Tests (WAnT). Results: Muscle fiber type composition was 29% MHC I

(pure slow-twitch fibers), 66% MHC IIa (pure fast-twitch fibers) and 5% hybrid

fibers (containing multiple MHC types). Mean ± SE fiber CSA and MND size were

3,183 ± 225 m² and 11,008 ± 1,331 m³, respectively. His grip strength was 78.4 kg,

isometric mid-thigh pull peak force was 37.7 N/kg, and vertical jump was 57.2 cm.

Additionally, the WAnT determined his peak power (PP): 1,075.89 W, relative PP:

10.45 W/kg, average power (AP): 838.87 W, fatigue index: 43.39%, and PP

decrease over 5 rounds: 12.1%. Conclusion: This elite MMA athlete exhibited a

homogeneous muscle fiber type (i.e. predominantly fast-twitch with few hybrids)

with relatively small MND sizes compared to untrained men in the literature (using

similar measures). These cellular characteristics may help partially explain the

athletes elevated whole muscle strength, power, and endurance performance. This

case study provides initial insight into the muscle physiology of high-level MMA

fighters; future research should continue investigating the myocellular

structure/function relationship among these unique athletes to further our

knowledge regarding elite human muscle physiology.

METHODS

Skeletal Muscle Phenotype and Performance of an

Elite Mixed Martial Artist

1 Muscle Physiology Laboratory, Department of Kinesiology, College of Health & Social Sciences, San Francisco State University

2 Biochemistry & Molecular Exercise Physiology Laboratory, Center for Sport Performance, California State University, Fullerton

CONCLUSIONRESULTS

CONTACT

PARTICIPANT

James R. Bagley1, Jose A. Arevalo2, Kylie K. Malyszek2, Jennifer A. Spencer2, Jakob Rosengarten2,

Saldiam R. Barillas2, Whitney D. Leyva2, Ryan T. McManus2, David Lee2, and Andrew J. Galpin2

Elite Male Mixed Martial Artist

Age: 33 y

Height 1.89 m

Mass: 102.1 kg

Competes at: 93.0 kg

MMA RECORD

8 wins; 2 losses

UFC RANKING

Top 10 in the Light

Heavyweight Division

Myocellular Structural Characteristics

Whole Muscle Functional Performance

Vastus Lateralis Biopsy

Single Fiber Isolation

MHC Fiber Type Continuum

Fluorescence Labeling

• Actin: Alexa Fluor 568 Phalloidin

• Myonuclei: DAPI

Laser Scanning Confocal Microscopy

Hand Grip Dynamometry Peak Isometric Mid-thigh Pulls Vertical Jump Height Wingate Anaerobic Power Test

Single Fiber Myosin Heavy Chain (MHC)

Determination via SDS-PAGE

Muscle Fiber Size and Myonuclei Content

Adapted from Bagley et al. 2012

This MMA fighter’s muscle exhibited:

• A homogenous muscle fiber type (66% MHC IIa

and 5% total hybrids)

• A small MND size, which may be related to

myocellular transport and repair efficiency

• High whole muscle peak power and only a 20%

drop in power over five rounds of Wingate Tests

Myosin Heavy Chain (MHC) Fiber Type Myonuclear Domain (MND) Size Whole Muscle Performance

Dr. Jimmy Bagley Email: [email protected]

@DrJimmy Bagley

Dr. Andy GalpinEmail: [email protected]

@DrAndyGalpin

MHC

Metabolism

Twitch

I I/IIa IIa IIa/IIx IIx

Slow

Oxidative Glycolytic

Fast

0

10

20

30

40

50

60

70

I I/IIa IIa IIa/IIx IIx TotalHybrids

% D

istr

ibu

tio

n

MHC Isoform

Elite MMA Fighter (n=149 fibers)

Sedentary Males (Klitgaard et al. 1990)

Untrained Males (Williamson et al. 2001)

Rec. Active Males (Kohn et al. 2007)

0

10000

20000

30000

40000

50000

MND Size (µm3)0

10

20

30

40

50

MN

D S

ize

(µ

m3;

x10

4)

Elite MMA

Fighter

n = 4 Fibers Analyzed

(sarcomere length

correction to 2.8 um)

Mean

MN

D R

an

ge

Mean MND Range

from Untrained Men

(~22-47.4 µm3; x104)

Liu et al. 2009

Cristea et al. 2010

Qaisar et al. 2011

Single Muscle Fiber

Myo

nu

cle

i

www.musclephyslab.com

@musclephyslab

5

6

7

8

9

10

11

12

Pat

Re

lati

ve P

eak P

ow

er

(W/k

g)

Repeated Wingate Tests (Rounds 1-5)

12.1% Drop in Power

Round

1 2 3 4 5

WINGATE ANAEROBIC

CYCLING TEST

Peak Power

1,075.89 W

Relative Peak Power

10.45 W·kg-1

Fatigue Index

43.39 %

His elevated whole muscle function may be partially explained by his unique

myocellular phenotype. Future research should continue to investigate the muscle

cell structure/function relationship among these unique athletes to further our

knowledge regarding elite human muscle physiology.

http://hhd.fullerton.edu/knes/Re

searchLabs/bmep/index.htm