Energy for Exercise

Biological Work Muscle Contraction * Digestion & Absorption Gland Function Establishment of Gradients Synthesis of New Compounds

Energy First Law of Thermodynamics Conservation of Energy – Energy can not be “Created” or “Destroyed” Our body simply transforms energy

A denosine T ri P hosphate “Fuel” for all processes in body Food energy → Rebuild more ATP ATP – Chemical, Potential Energy Phosphate bonds: “High Energy”

Phosphorylation ATP ←→ ADP + P + ENERGY CP ←→ C + P + ENERGY ATP Re-synthesis

Aerobic vs. Anaerobic Energy Aerobic: O 2 requiring energy production Anaerobic: No O 2 required for energy

Anaerobic Energy ATP stores Creatine Phosphate Anaerobic glycolysis

ATP – CP Energy System Small amount of ATP stored 85 g in whole body Must be re-synthesized CP: quick energy for ATP rebound  CP stored in larger quantities All out Exercise – 5 to 8 seconds

ATP – CP Energy System Increasing [ATP – CP] Exhaust ATP – CP stores → Adaptation Creatine Monohydrate supplementation

Creatine Monohydrate What it does Increases intracellular stores creatine phosphate. Increases anaerobic capacity Decreases accumulation of lactic acid* Delays onset of muscular fatigue Increase water retention in muscle*

Creatine Monohydrate What it does NOT do: Make you stronger / faster Increase muscle mass Decrease body fat % Increase aerobic capacity

Creatine Monohydrate Side Effects? Muscle cramps, pulls, strains, etc. Dehydration Liver / Kidney stress Atrophy of bank account

Anaerobic Glycolysis 6-Carbon Glucose → two 3-carbon pyruvic acid Occurs in “watery medium” 5% of total ATP from glucose

1.) Chemical bonds broken 2.) H + atoms are striped 3.) Two ATP formed Anaerobic Glycolysis

Glucose Pyruvic Acid (2) Energy H+H+ Lactic Acid (2) Acetyl Co-A (2) CO 2 & H + Krebs Cycle CO 2 H+H+ Energy ATP Mitochondria Inter Cellular Fluid To ETC Anaerobic Aerobic Fatty Acids Amino Acids

Aerobic Glycolysis Pyruvic Acid → Acetyl CoA Acetyl CoA → Mitochondria Krebs Cycle Chemical breakdown of Acetyl CoA & fragments of proteins & Lipids Frees H + & Produces CO 2 Generates small Amount of ATP

Aerobic Glycolysis Krebs Cycle H + → Electron Transport Chain ETC H + + Oxygen → H Energy

Krebs Cycle Energy ATP CO 2 H+H+ Electron Transport Chain ATP 2H + + O -- = H 2 O

100% % C ap ac ity of En er gy Sy st e m 10 sec30 sec2 min5 min + Energy Transfer Systems and Exercise Aerobic Energy System Anaerobic Glycolysis ATP - CP

Aerobic Capacity Capacity for aerobic resynthesis of ATP

O 2 Uptake During Exercise Oxygen Uptake: Use of oxygen by the cells for aerobic metabolism. VO 2 – ml O 2 /Kg/min. VO 2 max = Max O 2 uptake possible by individual Quantification of Aerobic Capacity

VO 2max VO 2max : Max Oxygen Uptake Further increases in exercise intensity (further energy requirement), results in NO increase in VO 2. Additional energy is produced via anaerobic glycolysis

VO 2max

What Effects Energy Capacity ? Diet (Glycogen stores, Metabolic State) Training Type of training, Altitude Gender Supplements / Drugs GENETICS

Energy Systems and Exercise Anaerobic / Aerobic Energy is always being produced Exercise intensity / duration determines the ratio Can be estimated with RER

RER aka RQ RER = CO 2 produced / O 2 consumed Carbohydrate: Hydrogen to Oxygen (2:1) → RER = 1.00 C 6 H 12 O 6 + 6O 2 → 6 CO H 2 O Lipid: Hydrogen > Oxygen (2:1) → RER = 0.7

Krebs Cycle Energy ATP CO 2 H+H+ Electron Transport Chain ATP 2H + + O -- = H 2 O

Lactic Acid Byproduct of Anaerobic Metabolism. Glucose Pyruvic Acid (2) Energy H+H+ Lactic Acid (2) ATP

Lactic Acid Causes Fatigue Irritation of local muscle Decreased pH of cellular environment & bloodstream Training increases lactate tolerance and decreases lactate formation at any given workload (by 20-30%)

Blood Lactate Threshold Point at which lactate begins to dramatically increase in the blood stream. (55% VO 2max ) Fatigue increases exponentially Caused by increase in anaerobic metabolism → Lactate production

Percent of VO 2 max 25%50%75%100% [Bl oo d La ct at e] Untrained Trained Effect of Training on Blood Lactate / Lactate Threshold LT

What Effects Lactic Threshold ? GENETICS Aerobic Capacity Fiber Type Training (adaptations..next slide)

Physiological )’s with Training (↓ Lactic Acid Build Up) ↑ in capillaries (↑ Density) ↑ aerobic enzymes ↑ mitochondria (# and size) ↑ Pain tolerance to Lactic Acid

Blood Lactate Threshold Lactate appearance in the bloodstream POWERFUL predictor of aerobic exercise performance! Higher LT = Better performance; less LA buildup, less fatigue

Lactate Processing Cori Cycle Muscle Cell Lactate Pyruvate Liver Glucose Lactate Pyruvate Glucose / Glycogen

Recovery Recovery Oxygen Uptake VO2 stays ↑ after exercise  Replenish ATP – CP  Reload hemoglobin  Supply elevated energy needs to cardiovascular system  Increased O 2 need 2 o heat

Recovery (cont.) Lactic Acid Removal (Heavy Exercise) Cori cycle Reconversion in muscle cell  Lactate → Pyruvate → Glucose Few seconds – few hours

Recovery (cont.) Light activity accelerates recovery Increased blood flow to muscle, liver, and heart  All can oxidize lactate for energy