Melissa is at the gym for a leg workout. They first start warming up by squattin
ID: 3481262 • Letter: M
Question
Melissa is at the gym for a leg workout. They first start warming up by squatting with only the squat bar (45 lbs): this is an easy task for her. Then, she goes on to the main part of her workout: she squats 5 repetitions of her maximum load (175 lbs), stop to rest for 60 secs, then do so again, for a total of 5 x 5 repetitions.
A. In comparison to lifting 45 lbs, what had to happen in Melissa’s muscle cells to allow her to lift 175 lbs?
B. Because the 175-lbs load is very heavy for Melissa, her coach has trained her to start her squat movement in a very specific position (see picture above). How does this position allow sarcomeres to generate more force?
C. Compare the 2 contractions (the one with 45 lbs and the one with 175 lbs): what is the expected difference in terms of latent period and muscle shortening velocity.
After her 5th block of 5 repetitions, Melissa’s coach asks her to perform an extra “surprise” set, but, despite her best efforts, she can only do 2 repetitions. This is similar to what you observed in PEX-02-04, when you stimulated the muscle at 150 stimuli/sec and you observed the tension reaching a plateau before decreasing.
D. Explain what is likely happening to Melissa and list 2 cellular processes that may explain why this situation is occurring.
E. In this workout, which type of muscle fibers is Melissa mostly relying on? Explain your answer and list 2 characteristics specific to these muscle fiber type that allow Melissa’s squatting workout.
Explanation / Answer
1.a.
Response. Process of lifting 45 lbs trains for correct sequence of muscle cells contractions pattern in CNS. 145lbs is for strength training. It increases fiber rearrangement in the cells.
B. Weight is kept along with center of gravity of her body. This gives proper weight distribution and minimize stress. And hamstring muscles and quadriceps muscles do work syngertical in squat position and gives more force.
C. Need more details.
D. Oxygen debt is the reason for the phenomenon. And lactic acid accumulated.
E. Workout depends on fiber type 2B which fast fiber.
It is for high power lift and easily fatigue prone.