Exercise Physiology

יובל חלד' פרופ

ש"תהמכון הלר למחקר רפואי

Physiology

• General physiology

• Cellular physiology

• System physiology

• Environmental physiology

• Hypobaric/ Hyperbaric physiology

• Exercise physiology

Exercise Physiology- Application

• Clinical diagnosis

• Rehabilitation

• Weight control

• Physical training

• Sport

• Research

Exercise Physiology- Application

גופנית פעילות

((physical activity

גופניאימון

((exercise training

physical fitness –כושר גופני היכולת לבצע מאמץ תת מרבי - aerobic endurance -ריאה-סבולת לב•

( שחייה למרחק/הליכה/ריצה)וממושך לאורך זמן היכולת להתמיד בפעולה מאומצת - muscle endurance -סבולת שריר•

לאורך זמן רב (רב של פעמים' עליות משכיבה לישיבה מס)

יכולת הגוף לחזור על - anaerobic endurance -אנאירובית-סבולת•שרירים גדולות ’ בהם משתתפות קב ועצימים מאמצים קצרים

( ספרינטים) היכולת להתגבר על התנגדות גבוהה - strength -כוח•

(הרמת משקולות) היכולת להפעיל כמות מרבית של - explosive power -כוח מתפרץ•

אנרגיה בתנועה פתאומית אחת כנגד התנגדות (קפיצה למרחק מהמקום, זינוק לריצת ספרינט)

היכולת לבצע תנועות חוזרות ורצופות בזמן הקצר - speed -מהירות • ביותר

('מ 100ריצת )

המשך physical fitness -כושר גופני

היכולת לשנות את מצב הגוף במרחב במשך הזמן - agility -זריזות• ( שינויי כיוון)הקצר ביותר

היכולת להניע איברים בטווח התנועה גבוה - flexibility -גמישות• "(שפגאט"ישיבת )

היכולת לפקח ולשלוט על אברי הגוף - balance -שיווי משקל• ( הליכה על קורה)

פעולות פשוטות ' היכולת להפוך מס - coordination -קואורדינציה• לפעולה מורכבת אחת

(רצף אלמנטים בתרגיל בהתעמלות)

Energy

• The ability to perform work

• Types of energy

• End product – heat

• First law in thermodynamics

Energy Cycle

Human, Animals

Carbohydrates,

Fat, Proteins

Green Plants

CO2 O2

H2O

Energy

Potential

Kinetic

Second Law of Thermodynamics

Heat

Entropy

Energy

• Work – Kgm

• Power- Kgm/min – Watt

1Joule/sec = 1Watt (w) = 6Kgm/min

Energy

• Kcal- the energy (heat) required to increase the temperature of 1 L water from 15oC to 16oC

1Kcal = 4.2Kjoule

1Kcal = 426Kgm

70W = 1Kcal/min

Energy in the Human Body

• Mechanical work

• Biosynthesis

• Active transport

• Heat production

Potential Energy in the Human Body

Carbohydrates Fat Proteins

4Kcal/gr 9Kcal/gr 4Kcal/gr

ATP

Kinetic Energy

Electrochemical Energy

ATP ADP + P + Energy + CO2 + H2O

Energy Requirements During Different Types of Metabolic Conditions

• Rest

• Light exercise

• Moderate exercise

• Intense exercise

• Extreme exercise

Energy Contribution During Different Types of Metabolic Conditions

Anaerobic Aerobic

Rest Light

Exercise

Moderate

Exercise Heavy

Exercise

Extreme

Exercise

Bioenergetics

• The ATP CrP system

• The glycolytic system

• The oxidative system

Bioenergetics

שומן

חלבון

ATP CrP

ATP-CrP System

ATP ADP + P + Energy

ATPase

CrP + ADP Cr + ATP CPK

Exhaustion: ADP ATP CrP

ATP-CrP System

• A few seconds of exercise

• Sprinting

• Jumping

• Power lifting

• Very limited energy

• Fast recovery

Anaerobic Glycolysis

Lactic acid O2

Anaerobic Glycolysis

Anaerobic Glycolysis (Lactic)

• 1- 2 min exercise

• 400 - 800 m run

• Using mostly muscle glycogen

• Product – lactate

• “Metabolic recovery” 1 hour +/-

• Smart use of glycogen

during competitive events

Pyruvic Acid

Lactic Acid

Glycolysis

(-)

(+)

Krebs Cycle

Negative Feedback (Fatigue)

1)

(-) 2)

(ATP)

Lactate Production m

mol/l

Lactate Pathways

Gluconeogenesis

Muscles Heart Liver

Buffering

CO2+H2O

Accumulation

Cori Cycle

Aerobic Glycolysis

The Krebs Cycle

2 ATP

H+ e-

NAD, FAD

CO2

The Oxidative System Amino Acids FFA

Aerobic Metabolism

• Long term exercise energy supply

• Low intensity exercise

• Using O2

• Rest energy supply

• Using mostly fat as energy

• Long recovery in long events (hours-days)

The relative contribution of aerobic and anaerobic energy during exercise

Energy Systems for Exercise - Summary

Energy Systems Mole of

ATP/min

Time to

Fatigue

Immediate: Phosphagen

(Phosphocreatine and ATP) 4 5 to 10 sec

Short Term: Glycolysis

(Glycogen-Lactic Acid) 2.5 1.0 to 2.0 min

Long Term: Aerobic 1 Unlimited

time

Anaerobic vs Aerobic Energy Systems

• Anaerobic

– ATP-PCR : ≤ 10 sec.

– Glycolysis: < 3 minutes

• Aerobic

– Krebs cycle

– Electron Transport Chain

– ß-Oxidation 2 minutes +

The relative contribution of aerobic

and anaerobic energy during maximal

exercise

10s 30s 60s 2min 4min 10min 30min 60min 120

90 80 70 50 35 15 5 2 1

10 20 30 50 65 85 95 98 99

% anaerobic

% aerobic

Time

The Relative Contribution of the Different Nutrients to Energy Consumption

Energy Sources

Carbohydrates

Sources:

Simple carbohydrates

Complex carbohydrates

Glucose Glycogen

Glycolysis

Aerobic Anaerobic

Carbohydrates

Glycogen

Glucose

Muscle

300 g = 1200 Kcal

Liver

100 g = 400 Kcal

Blood

25 g = 100 Kcal

Total <2000 Kcal

Carbohydrates

• The main energy source to muscles during exercise

• The main energy source to the nervous system

• Blood glucose level depends on nutrition and is regulated by the liver

• Extra amount of carbohydrate in the liver and muscle will be transformed into fat

• Gluconeogenesis

• Glycogenolysis

Glycemic Index (GI)

• GI is a measure of the effects of nutrients on blood glucose levels • Carbohydrates that break down rapidly during digestion releasing glucose rapidly into the bloodstream have a high GI • Simple Carbohydrates have high GI

GI

Fat

Triglyceride = Glycerol + 3 FFA

Oxidation of Fat

Oxidation of Fat

Lipolysis

glycerol Liver

gluconegeonesis

Fats Burn in Carbohydrate Flame

Beta

Oxidation

FFA

Triglycerides

Lactate Inhibits Lipolysis

Blood lactate

Blood

FFA

The mechanism protects effectively against an excessive,

undesirable FFA-outflow from adipose tissue in situations

in which FFA cannot be utilized

Fat as Energy

• Absorbed FFA Triglyceride

• 80,000 Kcal

• Energy supply mostly from fat tissue

• Glycerol Liver (and muscle) glucose

• FFA Liver Ketone bodies energy

• Spot reduction

Protein Metabolism

Protein Metabolism

N

Urea

Glucose Alanine Cycle

This is the third pathway of pyruvate

Contribution RelativeThe

of the Different Nutrients to

Energy Consumption

Energy Supply During Rest

Fat 2/3

Carbohydrates 1/3

Aerobic

ATP

+ Lactic Acid

ATP CO2 H2O + +

Anaerobic

Lactic

Intensity and Duration of Exercise

Relative Energy Supply During Exercise

Relative Energy Supply During Different Physical Activities

Fat Burning During Exercise

60% fat

180 Kcal fat

~ 20g fat

40% carbs

120 Kcal

1 hour walking

~ 300 Kcal

30% fat

180 Kcal fat

~ 20 g fat

70% carbs

420 Kcal

45 min running

~ 600 Kcal

Percentage vs. Quantity

1g fat ~ 9 Kcal

1g carbs ~ 4 Kcal

Conclusion

What matters is:

• Total energy burning

• Caloric balance

• High intensity exercise also contributes to fitness and health

What Influences the Magnitude of Contribution of the Different Nutrients to Energy

Consumption?

Intensity

Duration

Nutrition

Aerobic

fitness

The Influence of Nutrition* on Substrate Utilization During Long Term Exercise

0

50

100 0

50

100

0 1 2 3 4

Exhaustion

Running Time (hours)

Co

ntr

ibu

tio

n o

f c

arb

s t

o

the

me

tab

oli

c f

ue

l (%

)

Co

ntr

ibu

tio

n o

f fa

t to

the

me

tab

oli

c f

ue

l (%

)

Carbs diet

Regular diet

Fat diet

* Diets consumed for a

few days before the

experiment ר עומרי "שחר נייס וד: מתוך

2003, ענבר

Summary

Anaerobic Aerobic

Glucose

Fat

CrP ATP

The relative contribution of aerobic and anaerobic energy during exercise