OBLA

Question 1

what does OBLA stand for

Answer 1

onset of blood access

Question 2

lactate accumulation

Answer 2

-Lactate and lactic acid are not the same thing but the terms are often used interchangeably
-lactic acid is produced during anaerobic glycolysis
-the higher the intensity of exercise = more lactic acid is produced

Question 3

lactate accumulation

Answer 3

-lactic acid breaks down quickly – releasing H+ ions. The remaining compound combines with Na+ ions and K+ ions to form the salt lactate
-as lactate accumulates in the muscles more H+ ions are present and these increase acidity levels in the blood.

Question 4

lactate accumulation

Answer 4

-lactate in the muscles diffuses into the blood where it can be measured

Question 5

The lactate threshold and onset blood lactate accumulation (OBLA)

Answer 5

-as exercise intensity increases the body moves from an aerobic state to an anaerobic state
-the crossing of the aerobic/anaerobic threshold is known as the LACTATE THRESHOLD (the point where lactic acid rapidly accumulates in the blood)

Question 6

The lactate threshold and onset blood lactate accumulation (OBLA)

Answer 6

-you are always producing lactate but in aerobic situations this is quickly removed
-as exercise intensity increases and there is a lack of o2 to break down lactate you reach OBLA

Question 7

The lactate threshold and onset blood lactate accumulation (OBLA)

Answer 7

-at rest approximately 1-2 millimoles of lactate / liter blood
-OBLA occurs when the concentration of lactate is around 4mmol/l of blood

Question 8

The lactate threshold and onset blood lactate accumulation (OBLA)

Answer 8

v-measuring OBLA gives an indication of endurance capacity as some individuals can work at higher levels of intensity than others before OBLA (they can delay when the threshold occurs)

Question 9

how does exercise intensity affect the rate of lactate accumulation

Answer 9

the higher the exercise intensity, the greater the demand for energy (ATP) and the faster OBLA occurs. Fast twitch muscle fibres are used for high intensity exercise and can only maintain their workload with the use of glycogen as a fuel.

Question 10

how does muscle fibre type affect the rate of lactate accumulation

Answer 10

slow twitch fibres produce less lactate that fast twitch fibres. When slow twitch fibres use glycogen as a fuel, due to the presence of oxygen, the glycogen can be broken down much more effectively and with little lactate production.

Question 11

Lactate thresh is expressed as a percentage of VO2 max

Answer 11

-as fitness levels increase the lactate threshold becomes delayed
-an average performer may have a lactate threshold of 50-60% of their VO2 max
-elite performers may have a lactate threshold of 70-90% of their VO2 max