PHYSI-‐O-‐LYMPICS -‐ Physiology of Sprin7ng: Comparing UNBC Students, Olympic Sprinters and the Cheetah
Hannah Bjorndal and Vikas Sharma, Biol 321 Animal Physiology, Ecosystem Sciences and Management Program, UNBC
DISCUSSION/CONCLUSION
Sprin'ng is the act of running forward at maximum speed -‐ Sprin7ng 7mes differ between individuals -‐ This is due to level of training and gene7c makeup, and the resul7ng metabolic and muscle adapta7ons: Metabolic adapta-ons to sprin7ng ↑ (increase) ATP synthesis by increasing ac7vity of various enzymes = more rapid contrac7on and relaxa7on of muscles1 (Figure 1)
Muscle adapta-ons 1. Fiber Composi'on1 • ↑ percentage of fast twitch (FT) muscle fibers (type Iib)3 • ↑ force development and quicker contrac7on and
relaxa7on in FT fibers = quicker movement1 2. Sarcoplasmic Re'culum (SR)1 • SR in muscles more developed in FT fibers1 = ↑ [SR]4 • ↑ rate of Ca2+ release and uptake by SR1,4 = ↑ rate of muscle contrac7on and relaxa7on 3. Muscle size1 • ↑ in cross-‐sec7onal area of type I and II muscle fibers1 • Hypertrophy (↑muscle cell size)=↑power output1
OBJECTIVES/PREDICTION a. To examine how 100 meter sprint 7mes differ between UNBC
students and how they relate to Olympic sprint 7mes b. To compare human and cheetah sprint 7mes Hypothesis: Higher trained individuals would be faster than untrained individuals; cheetah would be the fastest
METHODS a. Measured 100m sprint 7mes for 18 random UNBC students (15 males and 3 females) on an indoor Tartan track b. Collected male Olympic 100m sprint 7mes from online database
The cheetah has a recorded short distance speed of 29m/s6 • nearly triple that of top Olympic sprinters Why is the cheetah so fast? • FT fiber composi7on ↑ but similar to
that of healthy human males. • High anaerobic and low aerobic enzyme
capaci7es in muscle cells = sprin7ng at high speeds compared to humans7
-‐ ↑ levels of enzymes of the glycoly7c pathway = ↑ glycogen u7liza7on rate = ↑ATP synthesis7
1Ross A., and Michael, L. Long-‐term metabolic and skeletal muscle adapta7on to short-‐sprint training. Sports Med 2001; 31: 1063-‐1082 2Thorstensson A., Sjodin B., and Karlsson J. Enzyme ac7vi7es and muscle strength aker ‘sprint training’ in man. Acta Physiol Scand 1975; 94: 313-‐8 3Cos7ll D.L., Daniels J., Evans W., Fink, W., Krahenbuhl, G., and B. Sal7n. Skeletal muscle enzymes and fiber composi7on in male and female track athletes. J Appl Physiol 40: 149-‐154. 4Ortenblad, N., Lunde, P.K., Levin, K., Andersen, J.L., and P.K. Pedersen. 2000. Enhanced sarcoplasmic re7culum Ca2+ following intermipent sprint training. Am J Physiol 279: R152-‐R160. 5Daily Record. hpp://www.dailyrecord.co.uk/sport/other-‐sports/athle7cs/usain-‐bolt-‐beaten-‐cheetah-‐study-‐1949124. (accessed Mar. 7, 2014). 6 Sharp, N.C.C. 1997. Timed running speed of a cheetah (Acinonyx jubatus). J Zool 241: 493-‐494. 7 Williams, T.M., Dobson, G.P., Mathieu-‐Costello, O., Morsbach, D., Worley, M.B., and J.A. Phillips. 1997. Skeletal muscle histology and biochemistry of an elite sprinter, the African cheetah. J Comp Physiol B 167: 527-‐535. 8Olympic.org. Olympic Games. hpp://www.olympic.org/olympic-‐results/london-‐2012/athle7cs/100m-‐m. (accessed Feb. 18, 2014). 9Sadoyama, T., Masuda, T., Miyata, H., and S. Katsuta. 1988. Fibre conduc7on velocity and fibre composi7on in human vastus lateralis. Eur J Appl Physiol 57: 767-‐771. 10Dubowitz, V. 1985. Muscle biopsy: a prac7cal approach. Bailliere Tindall, London. 11Catholic News Agency hpp://www.catholicnewsagency.com/news/va7can-‐invites-‐usain-‐bolt-‐to-‐address-‐religious-‐liberty-‐conference/. (accessed Mar. 7, 2014).
• Sprint 7mes of UNBC students varied considerably (12.97-‐18.82s) • This can be contributed to levels of fitness and engagement in
sprint related ac7vi7es • Individuals with faster 7mes visibly had larger muscle size, which
were likely contrac7ng and relaxing at higher rates due to increased metabolic enzyme ac7vity1
o Olympic sprinters were significantly faster (Wilcoxon test, W=0, p=3.205e-‐07) than UNBC students (Table 1,2) as expected because of sprint training by Olympic athletes
o Students had liple to no specific sprint training o The higher level of training of Olympic sprinters: delays fa7gue,
↑ ac7vity of enzymes producing ATP, ↑ percentage of FT fibers, ↑ development of the SR, and ↑ diameter of muscles.1
q The cheetah can achieve higher sprint speeds than human sprinters, owing to ↑ glycoly7c enzymes, but not fiber composi7on and size7, which is similar in both (Table 3)
ü Hypothesis met: Cheetah > Olympic sprinters > UNBC students REFERENCES
Table&1.&Fastest&men’s&100&meter&&sprint×&in&Olympics.8&
Name% Time%(s)% Name% Time%(s)%
U.&Bolt& 9.63& M.&Greene& 9.87&
U.&Bolt& 9.69& R.&Bailey& 9.88&
Y.&Blake& 9.75& F.&Fredericks& 9.89&
J.&Gatlin& 9.79& R.&Dawson& 9.89&
T.&Gay& 9.80& A.&Boldon& 9.90&
D.&Bailey& 9.84& W.&Dix& 9.91&
J.&Gatlin& 9.85& C.&Lewis& 9.92&
F.&Obikwelu& 9.86& C.&Martina& 9.93&
M.&Greene& 9.87& C.&Martina& 9.94&
Mean:%9.84&±&0.08&s&!!
Table&2.&UNBC&student&100m&sprint×,&&arranged&from&fastest&to&slowest.&Student' Time'(s)' Student' Time'(s)'
1& 12.97& 10& 14.50&
2& 13.28& 11& 14.84&
3& 13.68& 12& 15.02&4& 13.68& 13& 15.10&
5& 13.69& 14& 15.17&
6& 14.27& 15& 15.18&
7& 14.31& 16& 16.03&
8& 14.43& 17& 16.03&
9& 14.45& 18& 18.82&Mean:&14.74&±&1.32&s&!
RESULTS
Table&3.&Diameter&and&%&of&muscle&fibers&&in&human&males&and&the&cheetah.7,9,10&! Healthy!
Human!Males!Cheetah!!
%!FT!fibers!in!vastus!lateralis!
~70%& 83%&
Muscle!fiber!diameter!
82?85µm&& 40?80µm&
&
↑ATP
Glycolysis degrades
carbohydrates to generate
ATP ↑ Glycoly7c
enzyme ac7vity =↑ rate of glycolysis1,3
Crea7ne phosphokinase (CPK) converts phosphocrea7ne (PCr) to ATP2 ↑ CPK ac7vity depletes PCr quicker2
Myokinase resynthesizes ATP from ADP in muscles2
↑ Myokinase ac7vity2
Citric Acid Cycle (CAC) = ATP synthesis in oxida7ve
phosphoryla7on ↑ CAC enzyme ac7vity
= ↑ rate of CAC1,3
Figure 1. Increase in ac7vity of metabolic enzymes increases ATP produc7on.
Contact informa7on: [email protected], [email protected]
INTRODUCTION
Figure 2. A cheetah and Olympic sprinter, Usain Bolt.5
Figure 3. Men’s 4x100m relay at Olympic Games London 2012.11
We would like to thank Dr. Nikolaus Gantner for his guidance throughout the project. We are also apprecia7ve of the Northern Sports Center for allowing us to use their indoor track, and the BIOL 321 students who par7cipated in our data collec7on.
ACKNOWLEDGEMENTS
MARCH 13th 2014, UNBC PHYSI-‐O-‐LYMPICS, PRINCE GEORGE, BC
