Relative Muscular Endurance and Absolute Muscular Strength

LAB 1 RELATIVE MUSCULAR ENDURANCE This lab entails testing relative and absolute muscular endurance and strength, employing isotonic (aka, dynamic constant external resistance; DCER) measures. Muscular strength is the maximal force that can be applied one time (often referred to as a one repetition max, 1-RM); however, muscular endurance is the application of a sub-maximal force over a period of time or number of repetitions. The most common way to test muscular endurance is to lift a given sub-maximal weight and determine the number of repetitions which can be correctly performed prior to fatigue. Maximum repetitions are commonly denoted as RM. Thus 1-RM would be the maximum weight or resistance that could be overcome just one time. Likewise, 10-RM would indicate the maximum weight/resistance that would permit 10 repetitions before fatigue precluded the completion of any additional repetitions. Muscular strength and endurance can be measured from both absolute and relative perspectives. Absolute muscular strength involves the measurement and recording of strength without changing the results due to any relative variable (most commonly body weight). For example, if we measured the bench press strength of each member of the class and ranked the results, the person with the greatest 1-RM, would display the greatest absolute strength. However, in some cases this is hardly a fair measure because it does not take into account body weight. Relative muscular strength involves determining absolute strength first and then applying that performance to some relative measure (for example, body weight). If we determined the absolute bench press strength of each class member, and then divided each student’s result by his/her body weight; we would have a relative measure of strength. In this case, the person with the highest 1-RM in relation to his/her body weight would possess the greatest relative strength. Absolute muscular endurance could be determined by having each student in the class lift the same weight, recording the number of repetitions each could perform. Once again this does not take into account body weight. One of the most popular examples of this is the YMCA Bench Press Test. All males use an 80 lb. barbell and all females use a 35 lb. barbell. Subjects are tested with the same absolute resistance, and the number of repetitions correctly completed is determined. The person who performs the greatest number of repetitions would possess the greatest absolute muscular endurance. Once again, this measure does not take into consideration body weight, fat-free mass, etc… Relative muscular endurance could be determined by having each student lift a weight representing a percentage of their body weight, still evaluating the number of repetitions each could perform as the measure of muscular endurance. For example, instead of using a set weight in the bench press, like the YMCA Test, we might have males lift 75% of their body weight, while females lift 45% of their body weight, and then determine the maximum number of repetitions that can be correctly performed. This lab involves three DCER tests of relative muscular endurance, from which an evaluation of your muscular fitness can be assessed. The three tests will be the leg extension and bench press. For the bench press you will use free weights. Performance of these lifts will require a spotter for safety reasons. For the leg extension, use the Nautilus-counter-balanced machine. Regardless of method of test each concentric and eccentric phase of a repetition should take approximately one second; thus the total repetition should take approximately two seconds. Weights should not be permitted to bounce and correct lifting techniques should be implemented to avoid cheating. Before attempting these tests, you should warm-up. A good warm-up will include some light cardio (stationary bike, rower, treadmill, elliptical) for 5-8 minutes followed by performing the leg extension and/or bench press using much lighter weight than you anticipate using for your test. RELATIVE MUSCULAR ENDURANCE TESTS DATA TABLE BODY WEIGHT ______________(lbs.) Exercise Leg Extension Bench Press Totals Male % BW 65 Female % BW 50 75 45 N/A N/A Age ____________ Gender: M F Exercise Wt (lbs) Reps (RM) N/A N/A Points Fitness Category 1. Weigh yourself on the scale (remove your shoes first). Place results above. 2. Calculate Exercise Wt. (lbs) based on % of body weight (BW), and place beside appropriate exercise. 3. Perform maximum number of repetitions possible and place results in Reps (RM) column. 4. Using the Muscular Fitness Scoring Table determine appropriate points for your results and place them into the “points” category. 4. Using the Muscular Fitness Scoring Table determine your fitness category for each exercise based on the points achieved and place in Fitness Category column. 5. Compute your total points and determine your overall muscular fitness category using the Muscular Fitness Norm Chart (on the next page). MUSCULAR FITNESS SCORING TABLE Male Leg Ext. 0 – 3 reps 4-6 7-9 10 - 12 13 - 14 15 - 19 20 + Female Leg Ext. 0 – 1 reps 2-4 5-7 8-9 10 - 12 13 - 19 20 + Male Bench Press 0 reps 1-2 3-6 7 - 10 11 - 15 16 - 20 21 + Female Bench Press 0 reps 1 2-4 5-9 10 - 15 16 - 20 21 + Points 5 7 9 11 13 15 17 5 7 9 11 13 15 17 MUSCULAR FITNESS NORM CHART TOTAL POINTS CATEGORY < 18 POOR 19-21 FAIR 22-25 GOOD 26-30 VERY GOOD > 30 EXCELLENT Fitness Category Very Poor Poor Fair Good Very Good Excellent Superior Very Poor Poor Fair Good Very Good Excellent Superior ABSOLUTE AND RELATIVE MUSCULAR STRENGTH We just tested for relative muscular endurance using selected percentages of your body weight to determine the number of repetitions you could perform in the leg extension, bench press, and bicep curl. The DCER measures were tests of relative muscular endurance since you were lifting a percentage of your body weight; therefore, larger people were lifting heavier weights than lighter people. Since muscular strength is defined as the maximum force which can be developed one time, true strength measures involve one maximal effort. For certain populations including preadolescents, the elderly, those with hypertension (high blood pressure), and cardiac rehabilitation patients a one repetition maximum is not appropriate. Fortunately there is a way of predicting absolute and relative muscular strength from sub-maximal tests using prediction equations which have been proven to be quite accurate. This lab will involve the calculation of your predicted 1-RM bench press. ABSOLUTE MUSCULAR STRENGTH WORKSHEET AND PROCEDURES: 1. To accurately predict bench press 1-RM it is best if the number of submaximal repetitions is between 3-12 reps. The initial weight chosen is subjective, chose a weight you believe you can lift between 3-12 times. If you do fewer than 3 reps or more than 12 reps with the selected weight rest for 5-10 minutes, increase/decrease the weight and try again. Exercise Exercise Weight (lbs) Repetitions Bench Press 2. Calculate your 1-RM using the following formulae, first calculate % 1-RM then calculate 1-RM: % 1-RM = 100 – (# of reps x 2.5) 1-RM = weight lifted / (% 1-RM/100) For example, if a person completes 10 reps of a particular weight, the % of 1-RM is estimated to be 75% [100-(10 x 2.5)]. If those 10 reps were completed with a load of 130 lbs, the 1-RM is estimated to be 173 lbs [130/(75/100)]. Place your results in the table below Exercise Bench Press Predicted 1-RM Strength Category (percentile) 3. Determine your strength category for the bench press using the table below and place results in the table above. Men 18-29 yrs 30-50 yrs Women 18-29 yrs 30-50 yrs Well above avg (> 95 ) > 203 lbs > 183 lbs > 105 > 95 Above avg (75 th -95th ) 169-203 153-183 93-105 85-95 Average (25 th -74th ) Below avg (5th -24th ) 123-168 109-152 77-92 70-84 89-122 < 89 79-108 < 79 65-76 < 65 59-69 < 59 Category (percentile) th Well below avg (< 5 th ) RELATIVE MUSCULAR STRENGTH WORKSHEET AND PROCEDURES: 1. Calculate your relative muscular strength for the bench press: Relative muscular strength = (Predicted 1-RM/Body Weight) For example, if your predicted 1-RM for the bench press was 210 lbs and you weigh 175 lbs then your relative muscular strength is (210/175) = 1.2, then if you multiply that by 100 you get a percentage of 120%. Therefore, their relative muscular strength is 1.2 times their body weight or 120% of their body weight. Predicted 1-RM Body Weight Relative Muscular Strength Use the table below to find your relative muscular strength category Category Men Women Excellent ≥ 1.40 ≥ 0.85 Good 1.20 to 1.39 0.70 to 0.85 Average 1.00 to 1.19 0.60 to 0.69 Fair 0.80 to 0.99 0.50 to 0.59 Poor < 0.80 < 0.50 Category QUESTIONS 1. What is the difference between absolute and relative strength? 2. How can 1-RM be estimated from submaximal repetitions to fatigue? 3. A.) If you wanted to test the class’s absolute muscular endurance, describe how you would do so. B.) What lift would you use? C.) How would you determine who had the best absolute muscular endurance? 4. Describe a sport/activity/position where absolute muscular strength would be more important than relative muscular strength. 5. Describe a sport/activity/position where relative muscular strength would be more important than absolute muscular strength.