Question

question 1 (1.5 points)
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to determine muscle fatigue, calf muscle activity was conducted. every 10 sec, the results are provided below in table form. which conclusion is true?

1. number of calf raises the lowest around 10 sec.
2. increased lactic acid build up is possible around 50 sec.
3. same number of calf raises at 80 sec and 90 sec.
4. muscle fatigue starts at 20 sec.

Explanation:

• Option 1: At 10 sec, there are 12 calf raises. Looking at the data, 3 (at 90 sec) is lower than 12. So this option is false.
• Option 2: As muscle activity continues (like at 50 sec and beyond), anaerobic respiration can occur in muscles. Anaerobic respiration in muscles produces lactic acid. As the number of calf raises decreases (indicating muscle fatigue), increased lactic acid build - up (a cause of muscle fatigue) is possible.
• Option 3: At 80 sec, there are 5 calf raises and at 90 sec, there are 3 calf raises. So this option is false.
• Option 4: At 20 sec (10 calf raises), the number of calf raises is not the lowest (compared to later time - points like 30, 40, etc. where the numbers are 10,9,7, etc.). Muscle fatigue is a progressive decrease in muscle performance. Just because the number at 20 sec is less than at 10 sec does not mean fatigue starts exactly at 20 sec.

Answer:

1. Increased lactic acid build up is possible around 50 sec.