1. Sports Physiology Prof. dr. Zoran Valić Department of Physiology
University of Split School of Medicine

2. heavy exercise is extreme stresses for body
high fever  100%  in metabolism
marathon race  2000%  in metabolism

3. Female and Male Athletes:
muscle strength, pulmonary ventilation and CO  2/3-3/4 of values recorded in men
strength per cm2 equal (30-40 N/cm2)
marathon race  11% slower
two-way swim across English Channel
Testosterone (40% more muscle mass)
27% & 15% percent body fat, respectively
aggressiveness

4. Strength, Power, and Endurance of Muscles
What the muscles can do for you?
What strength they can give?
What power they can achieve?
How long they can continue their activity?

5. Muscle force (strength):
determined mainly by muscle size (training)
maximal contractile force – N/cm2
 quadriceps is 150 cm2 (F= N)
rupture & avulsion of tendons, displaced cartilages, compression fractures and torn ligaments

6. Holding strength (force) of muscles:
force that attempts to stretch out already contracted muscle
greater about 40% than contractile strength
Fquadriceps = N
internal tearing in the muscle

7. Power of Muscular Contraction:
mechanical work (W) performed by muscle is amount of force applied by the muscle multiplied by the distance over which the force is applied
power (P) is total amount of work that muscle performs in a unit period of time (t)

8. determined not only by the strength but also: distance of contraction and the number of times that it contracts each minute
power is generally measured in watts (W, or in kilogram meters (kg-m) per minute)

9. Maximal power of all muscles:
Duration of contraction
P (W, kg-m/min)
first 8 to 10 seconds
next 1 minute
next 30 minutes
1200/7000
650/4000
300/1700

10. Athletic (muscle) efficiency:
power  efficiency
velocity of 100-meter dash is only 1.75 times as great as velocity of a 30-minute race
depends on muscle supply by nutrients (glycogen)

11. Endurance (measured by time):
Nutrition
Time (min)
high-carbohydrate diet
mixed diet
high-fat diet
240
120 85

12. Amounts of glycogen stored in the muscle:
Nutrition
high-carbohydrate diet
Amount of glycogen (g/kg muscle)
high-carbohydrate diet mixed diet
high-fat diet 40 20 6

13. Muscle Metabolic Systems in Exercise:
phosphocreatine-creatine system
glycogen-lactic acid system
aerobic system

14. Phosphagen system: ATP (adenosine – PO3  PO3  PO3 -)
 high-energy P bonds (7.3 Cal/mol ATP)
amount of ATP sufficient for only about 3 s
phosphocreatine (creatine phosphate, creatine  PO3 -)
10.3 Cal/mol creatine, quick transfer
2-4 x more phosphocreatine than ATP
combined 8-10 s of maximal muscle power

16. Glycogen-Lactic Acid System:
glycogen  glucose (glycolysis, anaerobic metabolism)
two pyruvic acid molecules – 4 ATP
without oxygen – lactic acid
2.5 x more rapid than oxidative mechanism
provides additional 1.3 to 1.6 minutes of maximal muscle activity ( m)

17. Aerobic System:
glucose, fatty acids, and amino acids

18. ATP generation per minute:
Mechanism of Energy Supply
M ATP/min
phosphagen system
glycogen-lactic acid system
aerobic system 4
2.5 1

19. System endurance: Mechanism of Energy Supply Time phosphagen system
glycogen-lactic acid system
aerobic system
8-10 s
min
unlimited

21. Reconstitution of the lactic acid system:
removal of the excess lactic acid (extreme fatigue):
small portion is converted back into pyruvic acid
remaining lactic acid is reconverted into glucose (in the liver)

22. Recovery of the Aerobic System After Exercise:
Oxygen Debt
Recovery of Muscle Glycogen

23. Oxygen debt: body contains about 2 L of stored oxygen:
0.5 L in the air of the lungs
0.25 L dissolved in the body fluids
1L combined with the hemoglobin
0.3 L stored in muscle fibers (myoglobin)
all this stored oxygen is used within minute
9 L more reconstituting both phosphagen system and lactic acid system
total  11.5 L O2 – oxygen debt

25. Recovery of Muscle Glycogen:
complex matter, often requires days

27. it is important for an athlete to have a high-carbohydrate diet before a grueling athletic event
not to participate in exhaustive exercise during the 48 hours preceding the event

29. Effect of Athletic Training:
muscle strength is not increased without load
6 nearly maximal contractions performed in three sets 3 days a week – approximately optimal increase in muscle strength, without producing chronic muscle fatigue
30%  in strength during 6-8 weeks
simultaneously equal increase in muscle mass – muscle hypertrophy

31. Muscle Hypertrophy: heredity & testosterone secretion
30-60 % increase with training
increased diameter of the muscle fibers
increased numbers of fibers?

32. Changes that Occur Inside the Hypertrophied Muscle Fibers:
 numbers of myofibrils
 mitochondrial enzymes for 120%
 ATP and phosphocreatine for 60-80%
 stored glycogen for 50%
 stored triglyceride (fat) for %

33. Muscle Fibers Types:
fast-twitch muscle fibers – (gastrocnemius) – type II (white, a & b)
slow-twitch muscle fibers – (soleus) – type I (red)

34. Basic differences between:
diameter of fast-twitch fibers  2x larger
enzymes for anaerobic metabolism  2-3x more active in fast-twitch fibers (power)
slow-twitch fibers are organized for endurance, generation of aerobic energy (more mitochondria and myoglobin)
slow-twitch fibers – more capillaries
genetic inheritance

35. % of fiber types in quadriceps:
Activity
Fast-twich
Slow-twich
Marathoners
Swimmers
Average male
Weight lifters
Sprinters
Jumpers 18 26 55 63 82 74 45 37

36. Respiration in Exercise:
depends on sport discipline, duration of activity

37. Oxygen Consumption Under Maximal Conditions:
Type of subject
VO2MAX (mL/min)
Untrained average male
Trained average male
Male marathon runner
3600
4000
5100
oxygen consumption for
young man at rest is about 250 ml/min

39. Pulmonary Ventilation (PV):
Condition
PV (L/min)
Pulmonary ventilation at maximal exercise
Maximal breathing capacity

40. Limits of Pulmonary Ventilation:
MBC  50% higher than PV during maximal exercise
respiratory system is not normally the most limiting factor in delivery of oxygen
element of safety if:
exercise at high altitudes
exercise under very hot conditions
abnormalities in respiratory system

41. Effect of Training on Vo2 Max:
Vo2 Max – rate of oxygen usage under maximal aerobic metabolism
Vo2 Max of a marathoner is about 45 percent greater than that of an untrained person (genetically determined, many years of training)

43. Oxygen-Diffusing Capacity of Athletes:
Condition
DC (ml/min)
Nonathlete at rest
Nonathlete during ME
Speed skaters during ME
Swimmers during ME
Oarsman during ME 23 48 64 71 80
ME – maximal exercise

44. 3x increase in DC (activation of the pulmonary capillaries)
training procedures increases DC
partial pressures (O2 & CO2) remain nearly normal during strenuous athletics
regulation of breathing
negative effects of smoking (acute and chronic)

45. Cardiovascular System in Exercise:
delivering required oxygen and other nutrients to the exercising muscles
arterial blood pressure regulation
flow decrease during each muscle contraction
blood flow to muscles during exercise increases markedly (up to 25x)

47. Maksimalno povećanje protoka:
Condition
Blood Flow (ml/min/100g)
Resting blood flow
Blood flow during maximal exercise
3.6 90

48. Mechanisms of Blood Flow Increase:
vasodilation caused by the direct effects of increased muscle metabolism
moderate increase in arterial blood pressure (30%)
muscle pump
FMD
other theories

50. CO During Exercise: Condition CO (L/min) CO in young man at rest
Maximal CO during exercise in young untrained man
Maximal CO during exercise in average male marathoner
5.5 23 30
(35-40)

53. Relation of Cardiovascular Performance to Vo2 Max:
SV & HR increase to 95% of maximal
CO is 90% of maximal CO
PV is 65% of maximal breathing capacity
CO decreases for 50% between age of 20 and 80, maximal breathing capacity decreases even more, there is a reduction in skeletal muscle mass as well

54. Body Heat in Exercise: maximal efficiency 20-25%
energy converted in muscle work is ultimately transferred into heat
friction within muscles and joints
friction due to blood flow

55. Heatstroke:
with very hot and humid conditions or excess clothing body temperature can easily rise to 106°-108°F (41°-42°C)
extreme weakness, exhaustion, headache, dizziness, nausea, profuse sweating, confusion, staggering gait, collapse, unconsciousness  death
temperature-regulating mechanism fails
positive feedback-loop

57. Body Fluids and Salt in Exercise:
5-10 pound weight loss has been recorded in athletes in a period of 1 h during endurance athletic events in hot and humid conditions
loss of sweat, significantly  performance
weight loss 5-10% – muscle cramps, nausea
acclimatization, salt lost, aldosterone (increasing reabsorption of from sweat)
supplement of K+

58. Drugs and Athletes: caffeine (three cups of coffee  7% improve)
androgens or anabolic steroids (risk of cardiovascular damage)
amphetamines and cocaine (?, deterioration of performance, sudden death due to ventricular fibrillation)

59. Body Fitness Prolongs Life:
people who maintain appropriate body fitness have the additional benefit of prolonged life
mortality is 3x less in the most fit people than in the least fit

60. Mechanisms: greatly reduce cardiovascular disease (MI & stroke)
maintenance of lower blood pressure
reduced blood cholesterol and LDA, and increase in HDL
fit person has more bodily reserves to call on when does become sick (pneumonia, cardiac reserve)