Blood lactate levels before, during and after exercise were monitored of an athl
ID: 265745 • Letter: B
Question
Blood lactate levels before, during and after exercise were monitored of an athlete training for a 400 m sprint. The concentrations of lactate in this athlete’s blood plasma during a 400 m spring elevated from 15 uM to 170 uM within the first 10 seconds of running. During 10-50 seconds of the race, the lactate levels declined slowly reaching 40 uM after completion of the sprint.
(a) What caused the rapid rise in lactate concentration in the beginning of the race? (4 points)
(b) What caused the decline in lactate concentration and why did the decline occur slower than the increase? (4 points)
(c) The resting lactate concentration was 15 uM. Why it was not zero at resting? (4 points)
(d) Patients with defects in fructose 1,6-biphophatase results in very high levels of lactate in blood plasma. Explain this observation. (4 points)
(e) Experienced runners do not consume large amounts of glucose before a marathon. Based on your knowledge on insulin level changes after a meal, what is the biochemical basis for runners avoiding this fuel? (4 points)
Explanation / Answer
a and b
The formation of lactate occurs in anaerobic condition. When the athlete starts running his body greatly deficit of oxygen. In beginning of the race the intensity of muscle greatly increased to produce the lactate. As soon as the athlete run he maintain his speed and start taking the little oxygen which help in decreasing the lactate concentration.