(2) ENERGY PRODUCTION IN EXERCISEKUORMITUKSESSA. 1.Immediate energy stores 2.Anaerobic glykolysis 3.Aerobic energy production.

(2) ENERGY PRODUCTION IN(2) ENERGY PRODUCTION INEXERCISE EXERCISE

KUORMITUKSESSAKUORMITUKSESSA

1.1. Immediate energy storesImmediate energy stores2.2. Anaerobic glykolysisAnaerobic glykolysis3.3. Aerobic energy productionAerobic energy production

= Hi-energy phosphates adenocine-triphosphate = Hi-energy phosphates adenocine-triphosphate (ATP) and creatinephosphate (CP) –stores(ATP) and creatinephosphate (CP) –stores

IMMEDIATE ENERGY STORESIMMEDIATE ENERGY STORES

ATPATP:: storage in cells 80-storage in cells 80-100 g (in muscles about 50%, 100 g (in muscles about 50%, enough for max. work of 2-3 s )enough for max. work of 2-3 s )

CP (PCr)CP (PCr): stores 4-6 x that of ATP-: stores 4-6 x that of ATP-stores (sufficient for maximal work stores (sufficient for maximal work for 10 s )for 10 s )

-reactions don’t reguire oxygen-reactions don’t reguire oxygen

ATP and CP-stores in exerciseATP and CP-stores in exercise

Recovery of hi-energy phosphates is very quick! Recovery of hi-energy phosphates is very quick!

Creatine loading Creatine loading (creatiinimonohydrate, (creatiinimonohydrate, CrHCrH22O) has been shown to O) has been shown to

enhance performance in enhance performance in short maximal bouts, adds short maximal bouts, adds also body weightalso body weight

1. Under 30 s1. Under 30 s

ATP ja KPATP ja KP

2. 30s – 1½ min2. 30s – 1½ min

ATP, CP ja anaero-ATP, CP ja anaero-

bic glykolysisbic glykolysis

3. 1½-3 min3. 1½-3 min

Anaer. ja aer. glykol.Anaer. ja aer. glykol.

4. Over 3 min4. Over 3 min

Aerobic energy Aerobic energy

productionproduction

Maximal bouts of action:Maximal bouts of action:

ANAEROBIC GLYCOLYSISANAEROBIC GLYCOLYSIS

Glucose/glycogen Glucose/glycogen → pyruvic acid → pyruvic acid →→ lactic acid lactic acid

- no oxygen needed (anaerobic)- no oxygen needed (anaerobic)- 10 steps10 steps- occurs in watery medium of celloccurs in watery medium of cell- only 2/3 molecules of ATP is only 2/3 molecules of ATP is formed/glucose/glycogen molecule,also hydrogen formed/glucose/glycogen molecule,also hydrogen is produced to electron transfer chainis produced to electron transfer chain- activity of glycolysis depends on the activity of glycolysis depends on the amount/activity of regulatory enzymes, amount of amount/activity of regulatory enzymes, amount of oxygen and availability of glucoseoxygen and availability of glucose-end-product is pyruvic acid which is sent to end-product is pyruvic acid which is sent to aerobic process Krebs cycleaerobic process Krebs cycle-some of the pyruvic acid is turned into lactic acidsome of the pyruvic acid is turned into lactic acid

2 ATP:tä kuluu

- FT-cells contain more PCK (most important regulatory enzyme)

- breakdown of muscle glycogen more economical (net result 3 ATP molecules)

Glucose from blood into cell

In very heavy work all 6 hydrogen ions cannot be transformed with oxygen in electron transfer chain - acidosis

-Lactic acid is split into lactate and hydrogen ionsLactic acid is split into lactate and hydrogen ions

-Lactate is moved into bloodstreamLactate is moved into bloodstream

- even at rest there is some lactate in blood (red blood even at rest there is some lactate in blood (red blood cells and FT-cells)cells and FT-cells)

- used in energy production in muscles,especially heartused in energy production in muscles,especially heart

- gluconeogenesis (Cori cycle in liver) transforms gluconeogenesis (Cori cycle in liver) transforms lactate into glucose when enough oxygen is available lactate into glucose when enough oxygen is available in less powerful workin less powerful work

Cori cycle

On the other hand: On the other hand:

- lactate is produced in muscles even when there is no lactate is produced in muscles even when there is no lack of oxygenlack of oxygen

- lactate is also produced in liver,skin and heartlactate is also produced in liver,skin and heart

- lactate is the most important energy source of heart lactate is the most important energy source of heart in heavy workin heavy work

- use of immediate energy sources and anaerobic glycolysis are parallel energy sources-lactate starts to accumulate in working muscles before hi-energy phosphates are fully used

- transfer of lactate from blood is fastest at work rates of 30-45 % VO2max in cycle ergometer work

- on treadmill power should be 55-60 % VO2max

- muscular exhaustion is not equal to amount of lactate in muscle- Lactate accumulation and lowering of muscle pH both play a role in muscular exhaustion- diminishing muscle glycogen stores and hi-energy phosphates are also important factors in exhaustion- other apparent reasons are at central nervous system level and in neuromuscular junctions

Minutes