HHP 100 Foundations of Exercise Science
Name_________________________________
Lab # 5 10/6-10/13   Strength - Different types of Contraction

Purpose/Goals There are many ways to gain strength but they are all based on the "Over-
load Principle" which states that when the body is subjected to stress it will adapt to the demands
placed on it.  There are several types of contractions and several methods of overloading that
this lab will consider.

Textbook  Chapter 11

Equipment  Weight room - leg press machine, hand weights, tensiometer, steps for step
aerobics, goniometer, stop watch

Task  Perform the Maximum Leg Press test, Push-up test, and the following exercises;  
plyometric jumping exercise, isometric, isotonic, concentric and eccentric exercises

Procedure and Data
I.  Strength Tests
	A.  Perform the Maximum Leg Press test according to the instructions provided and
	     compare to chart (provided)

Score _______________________________    Rating_____________________________

	B.  Perform Push-up test according to instructions provided and compare to the chart
	     (provided)

Score_______________________________     Rating_____________________________

II.  Plyometrics:  In the main gym, start at the bottom of the bleachers with both feet at the same time jump from seat to seat up the bleachers. Once at the top you should run to the walk way between sections and run down the walk way.  At the bottom jump up the bleachers a second time.  Once at the top for the second time you are through.  Your partner should time your exercise and take your heart rate immediately afterward.

Time_______________________________    Heart Rate___________________

III.  Isometric:  Using the tensiometer in the lab as if you were attempting an arm curl, set the
cable so the elbows are at 45 degrees, 90 degrees, and 125 degrees for three different readings.
Note the isometric force generated at each angle.

45 ___________________    90 ______________________   125  _________________

IV.  Isotonic
	A.  Eccentrc:  With the R arm only performing an arm curl, select a comfortable hand
	weight.  You will perform the down portion of the exercise only.  Your partner will lift 
	the weight each time to the up position.

    Number of Lifts_____________________    Amount of Weight__________________

	B.  Concentric:  With the L arm only performing an arm curl, select a comfortable hand
	weight.  You will perform the up portion (concentric) of the exercise only.  Your partner 	will position the weight each time. Perform as many as possible

  Number of Lifts_____________________     Amount of Weight ___________________

	C.  Isotonic:  Perform the arm curl using both arms at the same time.  You may use hand weights or a bar.  Perform as many as you can using a comfortable weight.

  Number of Lifts_____________________     Amount of Weight ___________________

Analysis and Interpretation
1.  How do the Leg Press test and Push-up test differ other than one is for the legs and the other 
for the arms?

2.  Why are you not able to generate the same force at different angles of same motion 
(elbow flexion) in an isometric contraction?

Application
1.  Which type(s) of exercise would benefit a basketball player most?  WHY?

2.  Which was a more strenuous lift for you, contentric or eccentric?  What are your thoughts
as to why?

Questions
1.  What is going on in the sarcomere during an eccentric contraction?

2.  If you want to increase the force of contraction, what could you do immediately before the 
contraction?  Which type of exercise included this?