SPORTS PHYSIOLOGY I

vary between ⅔ or ¾ of recorded values in males

Female values for muscle strength, pulmonary ventilation, and cardiac output

• 3-4 kg/cm²

Maximal force of contractions is almost equal to

extra percentage of muscle in the male body

Most of the difference in total muscle performance is due to the

body fat

Extra percentage in the female body is

• 11% less than top males

  • Due to males having more muscle percentage

Top females had speeds

Testosterone

• have a powerful anabolic effect

  • Increases deposition of protein everywhere in the body

    • Especially muscles

  • Anabolic = muscle building

• 40% large muscles than female without testosterone

Average male, who does little to no sports activities, has…

Estrogen

•  accounts for some of the differences

  • Increases deposition of fat in the breasts, hips, and subcutaneous tissue

• 27% body fat

  • Compared to the 15% in the non-athletic male

Females have __% body fat

• What the muscles can do for you in terms of strength, power, and duration

Determined by mainly by its size

What is the Final common determinant of success in athletic events?

3-4 kg/cm2 = equal

Maximal contractile force is…

increased muscle streng

Male who is well-supplied with testosterone or enlarged the muscles through an exercise training program means…

MECHANICAL WORK AND MUSCLE POWER

• Amount of force applied by the muscle x distance of the force applied

Power

•  measures the amount of work done in a unit period of time

  • Measured by strength of muscle contraction, distance of contraction, and number of times it contracts in a minute

  • Measures efficiency in a period of time

  • Generally measured in kilograms meters per minute (kg-m)

• Can lift 1 kilogram to a height of 1 meter

  • If vertical

In 1 minute, one can lift kg to a health of _ meter if ___

• Move an object laterally against a force of 1 kilogram for a long distance of 1 meter

  • If horizontal

In 1 minute, one can Move an object ___ lly against a force of kilogram for a long distance of __meter

• If ____

7,000 kg-m/min

First 8-10 seconds

Focus: Power

4,000 kg-m/min

Next 60 seconds (1 minute)

Focus: Endurance

25% of the initial power surge

• In long-term endurance events, power is only __% of the initial power surge

MUSCLE ENDURANCE

• Depends on the nutritive support for the muscle

Especially the amount of glycogen stored in the muscle before the period of exercise

• igh-carbohydrate diet

  • Person with high-carbohydrate diet stores more muscle glycogen than on a mixed or high-fat diet

Endurance is greatly enhanced by…

High-Carbohydrate Diet

• 240 (4 hours)

  40 g/kg muscle

Mixed-Diet

120 min

20 g/kg muscle

High-Fat Diet

85 min

6 g/kg muscle

Adenosine Triphosphate (ATP)

• actual energy source used to cause muscle contraction

• Formula: Adenosine-PO3~PO3~PO3-

• Fuel used

Adenosine Diphosphate

• 1st phosphate is removed

Adenosine Monophosphate

2nd phosphate is removed

3 seconds

• Even in a trained athlete

• Enough for a 50-meter dash

•  it is important for new ATP to be formed 

  continuously.

Amount of ATP on the muscle is sufficient to sustain maximal muscle power for only…

Phosphagen Energy System (PES)

• combined amounts of ATP and cell phosphocreatine

GLYCOGEN-LACTIC ACID SYSTEM (GLA)

• ATP + Lactic Acid 

• Stored muscle glycogen can be split into glucose then be used for energy

Glycolysis

• initial stage occurring without using oxygen

  • Anaerobic metabolism

AEROBIC SYSTEM

• ATP + Oxygen 

• Oxidation of foodstuff in the mitochondria to provide energy

  • Glucose

  • Fatty acids

  • Amino acids

• Combines with oxygen to release tremendous energy to convert AMP and ADP into ATP

AEROBIC SYSTEM

• Portion of aerobic energy is depleted even in the early stages of heavy exercise due to Oxygen Debt and Depletion of Glycogen Stores

Oxygen Debt

• body normally contains 2 liters of stored oxygen (fo aerobic metabolism without breathing new oxygen)

  • 2 liters is not constant → depends on the body

• 500 mL of air (tidal volume in lungs)

• 250 mL (dissolved in body fluids)

• 1 liter (combined with hemoglobin)

• 300 mL (muscle fibers combined with myoglobin)

Oxygen debt is composed of

Alactic Oxygen Debt

• early portion

  • 3.5 liters

Lactic Acid Oxygen Debt

•  removing lactic acid in the latter portion

  • 8 liters

Recovery of Muscle Glycogen

• requires days for recovery

  • Diet plays a major influence

Principles of Maximum Resistance Training

• Muscle without load have minimal increase in strength

  • Even if exercised for many hours

• Muscles that contract at least 50% maximal force of contraction rapidly develops strength

  • Even if done only a few times per day

Significance of Maximal Resistance Training

• 6 nearly maximal muscle contractions for 3 sets and 3 days a week

  • Gives optimal increase in muscle strength

  • Without producing chronic muscle fatigue

• 6 contractions: 3 sets: 3 days a week 

Significances of Age Differences in Maximal Resistance Training

• Untrained young person can have 30% increase in strength during the first 6-8 weeks

• With equal percentage increase in muscle mass (Muscle Hypertrophy)

• Older populations may have atrophy due to sedentary lifestyle

Leads to more than 100% decrease in strength

MUSCLE HYPERTROPHY

• Average size of muscles is largely influenced by hereditary and rate or level of testosterone secretion

  • Leads to larger muscles in males than females

• With training, muscle size can change or increase up to 30-60%

• Mostly due to increased diameter of the muscle fibers

  • Some may split down the middle to form new fibers

• Increased number of myofibrils

  • In proportion to hypertrophy

• 120% increase in te components of PES

  • ATP and phosphocreatine

  • Increases energy reserves

• 50% increase in stored glycogen

• 75-100% increase in stored fat

What are the changes seen in muscle hypertrophy?

• Increased capabilities of both aerobic and anaerobic systems to up to 45%

  • Maximum oxidation rate

  • Efficiency of oxidative metabolic system

Changes in muscle hypertrophy lead to