This is an excerpt from Laboratory Manual for Exercise Physiology 3rd Edition With HKPropel Access-Loose-Leaf Edition by G. Gregory Haff & Charles L. Dumke.
Technological advancements have made it easier for the practitioner to quantify the velocity of movement during resistance training (10). These technologies (i.e., accelerometer, linear position transducer, linear encoder, or inertial movement sensor) allow for LV profiles to be created from the velocities of movement (peak velocity or mean velocity) determined during a series of progressively loaded sets for a resistance training exercise, such as the bench press. Although LV profiles can be created for almost any resistance training exercise, most of the scientific literature on the LV profile has used the bench press (i.e., Smith machine or free-weight bench press).
Regardless of which resistance exercise is used to create the LV profile, Weakley and colleagues (60) suggest the assessment can be accomplished in four simple steps. During the first step, the individual should complete a 1RM test with standard procedures (see laboratory activity 12.1); the velocity of movement is monitored as the load progressively increases toward maximum. After 48 h of rest, the subject carries out the second step, which involves performing an incremental loaded test with one of two methodologies (60). In the first method, the subject performs three repetitions at 20%, 40%, and 60% of 1RM and one repetition at 80% and 90% of 1RM, with 2 min between sets (10). In the second method, often referred to as the two-point method, two loads of ~40-45% of 1RM and ~80-85% of 1RM are tested (24). With this method, 2-3 repetitions are performed at the low load, and 1-2 repetitions are performed at the higher load, with 2 min between sets. The third step involves taking the fastest repetitions from each intensity tested, plotting the mean velocity achieved against the corresponding percentage of 1RM, and then applying a linear line of best fit to extrapolate the regression equation (table 12.9) (60). The final step is to create a velocity table from the regression equation that can be used to guide the training process.
Velocity Measurements During the 1RM Bench Press
Before starting the 1RM test, consult with the subject to inquire about their current 1RM, or estimate their perceived maximum. This process can be challenging with untrained individuals because it is likely to be speculative at best. As noted in laboratory activity 12.1, one possible method for estimating 1RM of untrained individuals is to estimate it from the subject’s body mass (i.e., female = 0.35 × body mass; male = 0.60 × body mass). When using this method, it is generally recommended that the maximum weight used be 79 kg (175 lb) for men and 64 kg (140 lb) for women. With athletes, in contrast, it is relatively easy to determine the perceived maximum because you can likely use the actual 1RM or estimates based on the individual’s training weights. This value should be noted on the individual data sheet and used to calculate the 20%, 40%, 60%, 80%, and 90% loads needed to conduct the test. Once the loads have been determined, use the following steps to conduct the assessment.
Step 1: Set up the bench press area with all the equipment needed to conduct the test. Attach the velocity measurement device to the barbell; make sure there is a Bluetooth connection between the device and the tablet or smartphone that will be used to collect the velocity data.
Step 2: Gather basic data (e.g., age, height, weight) for the individual data sheet as described in laboratory activity 1.1. Have the subject put on their shoes and move to the test area.
Step 3: While the subject is putting on their shoes, enter their basic data into the velocity measurement device software. Depending on the software, you may need to enter the loads that are going to be tested at this time.
Step 4: Lead the subject through a 10 min warm-up that includes dynamic warm-up activities such as arm swings to prepare the upper body for the bench press test.
Step 5: Load the bar with the weight corresponding to the subject’s warm-up weight (20% of perceived maximum). Move into an appropriate spotting position behind the bench (figure 12.5a).
Step 6: Instruct the subject to lie on their back on the bench in a five-point-contact position (figure 12.5a). The subject’s body should be positioned on the bench such that the racked bar is directly above the eyes. All sets should begin in this position.
Step 7: Upon the subject’s command, lift the bar off the rack using an alternated grip. Guide the bar to a position over the subject’s chest, and then release the bar to the subject (figure 12.5b).
Step 8: Have the subject lower the bar in a controlled manner to touch the chest at approximately nipple height, while maintaining the five points of contact and inhaling (figure 12.5c). During this movement, keep your hands in the alternated position near the bar but not touching the bar.
Step 9: The subject should push the bar upward until the elbows are fully extended while maintaining the five points of contact and exhaling (figure 12.5d). At the end of the prescribed number of repetitions (3), grasp the bar with an alternated grip and place it back on the rack (figure 12.5e).
Step 10: After the subject completes 3 repetitions with 20% of 1RM, quickly write down the mean and peak velocities for each repetition on the individual and group data sheets. Then change the load to the predetermined second-set load. The subject should have only 2 min to rest during this change.
Step 11: After the 2 min rest interval, repeat steps 6 through 9, with the subject performing 3 repetitions with 40% of 1RM. Quickly write down the mean and peak velocities for each repetition in the appropriate location on the individual and group data sheets. Then change the load to the predetermined third-set load. The subject should have only 2 min to rest during this change.
Step 12: After the 2 min rest interval, conduct steps 6 through 9 again, with the subject performing 3 repetitions with 60% of 1RM. Quickly write down the mean and peak velocities for each repetition in the appropriate location on the individual and group data sheets. After completing this task, change the load to 80% of perceived maximum for the fourth set, while the subject rests for 2 min.
Step 13: After the 2 min rest interval, conduct steps 6 through 9 again, and have the subject perform 1 repetition with the 80% load. Quickly write down the mean and peak velocity for the repetition in the appropriate location on the individual and group data sheets. After completing this task, change the load to the 90% of perceived maximum for the fifth-set load.
Step 14: After a 3 min rest, repeat steps 6 through 9, with the subject performing 1 repetition with 90% of 1RM. After the subject completes the repetition at 90% of 1RM, quickly write down the mean and peak velocities achieved in the appropriate location on the individual and group data sheets.
Step 15: While the subject rests for 3 min, increase the load by 5 to 10 kg if the attempt appeared relatively easy. If, however, the attempt was more difficult, increase the load by 1 to 5 kg, depending on the weights available.
Step 16: Repeat steps 6 through 9, continuing to have the subject perform only 1 repetition until a 1RM is achieved.
Step 17: If an attempt is unsuccessful, reduce the load by 1 to 10 kg, but keep it above the last successful attempt, and have the subject rest for 3 min.
Step 18: After the 3 min rest, have the subject perform another attempt with the procedures outlined in steps 6 through 9.
Step 19: If the attempt is successful, increase the load by a small amount (1-5 kg) and repeat step 18. If the attempt is unsuccessful, the 1RM load is determined as the heaviest load successfully completed. Record the maximum weight lifted and the mean and peak velocities achieved during this repetition in the appropriate location on the individual and group data sheets.
Step 20: Using Microsoft Excel or similar software, determine the slope and intercept for both the mean and peak velocities (table 12.13).
Step 21: Record the determined slopes and intercepts on the individual data sheet.