9) **** Lactate **** Flashcards
Where does Lactate come from?
? production of lactate is associated with Hydrogen (H+) ion production
Glycolytic production of lactate is associated with Hydrogen (H+) ion production
Glucose -> 2lactate + 2(H+) + 2ATP
Glycogen -> 2 lactate 1(H+) + 3ATP
Hydrolysis of ATP (ATP + H2O -> ADP + P + H+) requires water
H+ ions produced -> Metabolic Acidosis (If aerobic, these H+ ions will be removed // no O2 = metabolic acidosis)
What enzyme converts Pyruvate to Lactate?
Lactate dehydrogenase
Lactate dehydrogenase is responsible for?
Conversion of pyruvate to lactate
True or false:
Lactate is a waste product of anaerobic metabolism which gives rise to fatigue and mm pain
False
Metabolic fuel continuously formed and utilized even under fully aerobic conditions
Why might metabolic acidosis occur?
Hydrogen ions produced during the non-MIT Hydrolysis of ATP
ATP + H2O -> ADP + P + H+ (requires water)
H+ ions produced -> Metabolic Acidosis (If aerobic, these H+ ions will be removed // no O2 = metabolic acidosis)
Lactate removal after intense exercise
SLIDE 5 Lactate is removed more rapidly with ? recovery?
active or passive?
Lactate is removed more rapidly with active recovery?
Active Recovery (cooldown):
Optimal intensity: ~30-40% of VO2max (low intensity so as not to increase lactate) - must be low enough that energy is fully coming from aerobic metabolism
Most lactate is removed within 60-100min regardless of recovery method
- Passive recovery: 2hrs to fully recover
- Active recovery: 50 mins to fully recover
Lactate removal after intense exercise
SLIDE 5 Lactate is removed more rapidly with active Recovery
- Optimal intensity of ~30-40% of ?
Active Recovery (cooldown):
Optimal intensity: ~30-40% of VO2max
- low intensity so as not to increase lactate
— must be low enough that energy is fully coming from aerobic metabolism
Most lactate is removed within 60-100min regardless of recovery method
- Passive recovery: 2hrs to fully recover
- Active recovery: 50 mins to fully recover
Lactate removal after intense exercise
SLIDE 5 IMAGE Lactate is removed more rapidly with active Recovery;
Why is an intensity of ~30-40% of VO2 max optimal for Lactate removal?
Active Recovery (cooldown):
Optimal intensity: ~30-40% of VO2max
- low intensity so as not to increase lactate
— must be low enough that energy is fully coming from aerobic metabolism
Most lactate is removed within 60-100min regardless of recovery method
- Passive recovery: 2hrs to fully recover
- Active recovery: 50 mins to fully recover
Uses of lactate
SLIDE 7 What happens to most (70%) of lactate produced?
70% of lactate is converted back to pyruvate to enter aerobic metabolism
- Occurs in same cell if intensity of exercise decreases (MM catches up)
- Otherwise == Lactate Shuttle -> wherein lactate is transported to another cell or tissue with a lower rate of lactate production to be used for fuel (MCT proteins)
SLIDE 7 What type of proteins function as Lactate Shuttles?
Monocarboxylate transporter (MCT) proteins
- facilitate the mvmt of lactate between cells and tissues and within cells
Lactate moves from the cell/tissue from which it was produced to another with lower rate of lactate production
- From fast twitch (type II) to slow twitch (type I; oxidative) MM fibers
- To heart and brain
Uses of lactate
What happens to the lactate that isn’t converted back to pyruvate?
- 10% converted to?
- 20% converted to?
What happens to the lactate that isn’t converted back to pyruvate?
- 10%: converted to amino acids
- 20%: converted to glucose in the liver (cori cycle) and kidney
What happens to the lactate that isn’t converted back to pyruvate?
- 10%: converted to ?
- 20%: converted to glucose in the ? and ?
What happens to the lactate that isn’t converted back to pyruvate?
- 10%: converted to amino acids
- 20%: converted to glucose in the liver (cori cycle) and kidney
Increased blood lactate levels downregulates ?
Increased blood lactate levels downregulates FFA and glucose utilization as energy substrate
- downregulate so as to promote the use of LACTATE (thus decreasing lactate accumulation)
What happens to lactate that enters the mitochondria?
Lactate in the peroxisome?
Lactate in the mitochondria is converted to pyruvate
Peroxisome -> breaks down lactate
Lactate produced via ? in muscles is transported to the liver and converted to ?
Lactate produced via Anaerobic Glycolysis in muscles is transported to the liver and converted to Glucose (Gluconeogenesis)
- glucose returns to muscles and is metabolized back to lactate (cycle continues until MM metabolism decreases and lactate stops being produced)
Gluconeogenesis -> generation of glucose from non carbohydrate sources
SLIDE 8 What is the Cori cycle
a metabolic pathway in which lactate, produced by anaerobic glycolysis in muscles, is transported to the liver and converted to glucose, which then returns to the muscles and is cyclically metabolized
If lactate is produced faster than the cori cycle can remove it = onset of blood lactate (when lactate in blood»_space; resting levels)
Does lactate cause next day mm soreness (DOMS)
Does “lactic acid” cause DOMS?
DOMS is caused by sarcomere damage
- Lactic acid is not produced in the body (lactate instead)
- Lactate does not cause acidification
- Lactate removal is rapid (most removed within 60-100min following exercise)
DOMS =Delayed onset MM soreness (24-48hrs post intense exercise)
Blood lactate curve w/ exercise
When do blood lactate levels start to rise?
Blood lactate levels begin to rise when rate of production exceeds rate of uptake (clearance)
- Lactate threshold
What factors contribute to increased blood lactate levels and can be modified via training?
1) Capillary (blood) supply (clearance ability)
2) Mitochondria density
Why do Lactate levels increase
Three factors leading to rising blood lactate levels?
(1) Increased rate of glycolysis (glycogen/glucose) ⟶ increased Lactate (present at rest and during low-intensity exercise)
(2) Increased recruitment of Fast Twitch (Type II) MM fibers
(3) Imbalance between lactate production and removal (mitochondria backed up)
(1) Increased rate of glycolysis (glycogen/glucose) ⟶ ↑ Lactate
- Lactate not just present in anaerobic conditions but present at rest and during low-intensity exercise as well
- Increase exercise intensity ⟶ ↑ use of glucose as energy source ⟶ ↑ production of lactate
(2) Increased recruitment of Fast Twitch (Type II) MM fibers
- Low intensity exercise, greatest recruitment of Slow twitch (Type I; slow oxidative) MM fibers
- Increase exercise intensity ⟶ ↑ recruitment of fast twitch (Type II) MM fibers ⟶ ↑ rate of glycolysis & lactate production
(3) Imbalance between lactate production and removal (mitochondria backed up)
- Lactate is fuel metabolized within the Mitochondria of slow and fast, oxidative (Type I and Type IIa) mm fibers during oxidative-phosphorylation
- Lactate is metabolized in the heart, brain, liver and kidneys
(1) Increased rate of glycolysis (glycogen/glucose) ⟶ ↑ Lactate
- Lactate present under what conditions ?
- Increase ? ⟶ ↑ use of glucose as energy source ⟶ ↑ production of lactate
(1) Increased rate of glycolysis (glycogen/glucose) ⟶ ↑ Lactate
- Lactate not just present in anaerobic conditions but present at rest and during low-intensity exercise as well
- Increase exercise intensity ⟶ ↑ use of glucose as energy source ⟶ ↑ production of lactate
(2) Increased recruitment of Fast Twitch (Type II) MM fibers
- Low intensity exercise, greatest recruitment of Slow twitch (Type I; slow oxidative) MM fibers
- Increase exercise intensity ⟶ ↑ recruitment of fast twitch (Type II) MM fibers ⟶ ↑ rate of glycolysis & lactate production
(3) Imbalance between lactate production and removal (mitochondria backed up)
- Lactate is fuel metabolized within the Mitochondria of slow and fast, oxidative (Type I and Type IIa) mm fibers during oxidative-phosphorylation
- Lactate is metabolized in the heart, brain, liver and kidneys
Why lactate levels increase
(2) Increased recruitment of Fast Twitch (Type II) MM fibers
- Low intensity exercise, greatest recruitment of ? MM fibers
- Increase exercise intensity ⟶ ↑ recruitment of Fast twitch (?) MM fibers ⟶ ↑ rate of ? & lactate production
(2) Increased recruitment of Fast Twitch (Type II) MM fibers
- Low intensity exercise, greatest recruitment of Slow twitch (Type I; slow oxidative) MM fibers
- Increase exercise intensity ⟶ ↑ recruitment of fast twitch (Type II) MM fibers ⟶ ↑ rate of glycolysis & lactate production
(1) Increased rate of glycolysis (glycogen/glucose) ⟶ ↑ Lactate
- Lactate not just present in anaerobic conditions but present at rest and during low-intensity exercise as well
- Increase exercise intensity ⟶ ↑ use of glucose as energy source ⟶ ↑ production of lactate
(3) Imbalance between lactate production and removal (mitochondria backed up)
- Lactate is fuel metabolized within the Mitochondria of slow and fast, oxidative (Type I and Type IIa) mm fibers during oxidative-phosphorylation
- Lactate is metabolized in the heart, brain, liver and kidneys
Why lactate levels increase
(3) Imbalance between lactate production and removal
- Lactate is fuel metabolized within the ? of slow and fast-oxidative (Type I and Type IIa) mm fibers during oxidative-phosphorylation
- Lactate is metabolized in the ?, ?, ? and ? (4 organs)
(3) Imbalance between lactate production and removal (mitochondria backed up)
- Lactate is fuel metabolized within the Mitochondria of slow and fast, oxidative (Type I and Type IIa) mm fibers during oxidative-phosphorylation
- Lactate is metabolized in the heart, brain, liver and kidneys
(1) Increased rate of glycolysis (glycogen/glucose) ⟶ ↑ Lactate
- Lactate not just present in anaerobic conditions but present at rest and during low-intensity exercise as well
- Increase exercise intensity ⟶ ↑ use of glucose as energy source ⟶ ↑ production of lactate
(2) Increased recruitment of Fast Twitch (Type II) MM fibers
- Low intensity exercise, greatest recruitment of Slow twitch (Type I; slow oxidative) MM fibers
- Increase exercise intensity ⟶ ↑ recruitment of fast twitch (Type II) MM fibers ⟶ ↑ rate of glycolysis & lactate production
What is the Lactate threshold?
Lactate threshold is the exercise intensity or relative intensity at which blood lactate begins to increase above baseline concentration
- Point at which during incremental exercise lactate production exceeds the rate of lactate clearance (removal)
What is Onset of Blood Lactate Accumulation (OBLA)?
OBLA -> occurs at higher relative exercise intensities where lactate production exceeds at a rate which it cannot be broken down; occurs where blood lactate reaches 4.0mM
Second inflection point on graph
Beyond OBLA lactate levels will increase drastically
Lactate threshold (LT) is a good predictor of athletes potential for ? exercise or ? fitness
Lactate threshold (LT) is a good predictor of athletes potential for endurance exercise or submaximal fitness
In an untrained individual when does the Lactate threshold begin relative to VO2max?
LT begins at 50-60% of VO2max
- aerobic training can increase this percentage (lactate training)
What is Lactate training?
Lactate threshold training means increasing exercise intensity so you train at or just above your LT heart rate.
- This training can be interval training or steady-state training.
Training below LT -> lactate produced by muscles is removed without it building up = less endurance “gains”
How do you improve lactate threshold?
1) Decrease rate of lactate accumulation
2) increase rate of Lactate clearance
Build aerobic “engine” or ability to produce energy aerobically (endurance)
- Train fat burning enzymes to oxidize more fat
- Train body to more efficiently break down carbohydrates
Aerobic based training will DECREASE rate of lactate production and shift Lactate Threshold UP
