Acute Effect of Biomechanical Muscle Stimulation on the Counter-Movement Vertical Jump Power and Velocity in Division I Football Players.

Jacobson, BH, Monaghan, TP, Sellers, JH, Conchola, EC, Pope, ZK, and Glass, RG. Acute effect of biomechanical muscle stimulation on the counter-movement vertical jump power and velocity in division I football players. J Strength Cond Res 31(5): 1259-1264, 2017-Research regarding whole body vibration (WBV) largely supports such training augmentation in attempts to increase muscle strength and power. However, localized biomechanical vibration has not received the same attention. The purpose of this study was to assess peak and average power before and after acute vibration of selected lower-body sites in division I athletes. Twenty-one subjects were randomly assigned to 1 of 2 conditions using a cross-over design. Pretest consisted of a counter-movement vertical jump (VJ) followed by either localized vibration (30 Hz) to 4 selected lower-body areas or 4 minutes of moderately low-resistance stationary cycling (70 rpm). Vibration consisted of 1 minute bouts at each lower-leg site for a total of 4 minutes followed by an immediate post-test VJ. Repeated measures analysis of variance yielded no significant differences (p > 0.05) in either peak power or peak velocity. Similarly, no significant differences were found for average power and velocity between conditions. It should be noted that, while not significant, the vibration condition demonstrated an increase in peak power and velocity while the bike condition registered slight decreases. Comparing each of the post-VJ repetitions (1, 2, and 3) the vibration condition experienced significantly greater peak power and velocity from VJ 1 to VJ 3 compared with the bike condition which demonstrated no significant differences among the post-test VJs. These results yielded similar, although not statistically significant outcomes to previous studies using WBV. However, the novelty of selected site biomechanical vibration merits further investigation with respect to frequency, magnitude, and duration of vibration.

Relationship Between Selected Strength and Power Assessments to Peak and Average Velocity of the Drive Block in Offensive Line Play.

Jacobson, BH, Conchola, EC, Smith, DB, Akehi, K, and Glass, RG. Relationship between selected strength and power assessments to peak and average velocity of the drive block in offensive line play. J Strength Cond Res 30(8): 2202-2205, 2016-Typical strength training for football includes the squat and power clean (PC) and routinely measured variables include 1 repetition maximum (1RM) squat and 1RM PC along with the vertical jump (VJ) for power. However, little research exists regarding the association between the strength exercises and velocity of an actual on-the-field performance. The purpose of this study was to investigate the relationship of peak velocity (PV) and average velocity (AV) of the offensive line drive block to 1RM squat, 1RM PC, the VJ, body mass (BM), and body composition. One repetition maximum assessments for the squat and PC were recorded along with VJ height, BM, and percent body fat. These data were correlated with PV and AV while performing the drive block. Peal velocity and AV were assessed using a Tendo Power and Speed Analyzer as the linemen fired, from a 3-point stance into a stationary blocking dummy. Pearson product analysis yielded significant (p ≤ 0.05) correlations between PV and AV and the VJ, the squat, and the PC. A significant inverse association was found for both PV and AV and body fat. These data help to confirm that the typical exercises recommended for American football linemen is positively associated with both PV and AV needed for the drive block effectiveness. It is recommended that these exercises remain the focus of a weight room protocol and that ancillary exercises be built around these exercises. Additionally, efforts to reduce body fat are recommended.

Longitudinal morphological and performance profiles for American, NCAA Division I football players.

The aim of this study was to determine the changes in anthropomorphism and performance over a 4-year eligibility career of American football players. A total of 92 offensive and defensive linemen and 64 skill (wide receivers and defensive backs) player observations were included in the analysis. Data from preseason testing over a 7-year period were compiled, sorted, and analyzed by players' year in school. Assessments of strength included 1 repetition maximum bench press, squat, power clean, and a 225-lb maximum repetition muscle endurance test. Power and speed measures included vertical jump (VJ) and 40-yd (36.6-m) sprint. All strength measures improved significantly (p < 0.05) over the years of training. Skill players demonstrated a significant increase in power between years 1 and 2 but at no other time. Linemen did not demonstrate significant changes in VJ. Speed did not change significantly for either group over the 4 years of training. These data provide a theoretically predictable 4-year rate of change in anthropometric, strength, and power variables for Division I football players. By having a longitudinal assessment of expected physical improvement, it may be possible for strength training personnel to determine those who may need additional attention in an area to more closely improve as expected. Additionally, it is suggested that elite athletes may possess genetically superior attributes and therefore, when selecting athletes, particular attention should be paid to the selection of those who have previously demonstrated superior speed and power.

The influence of ratio and allometric scaling procedures for normalizing upper body power output in division I collegiate football players.

The purpose of the present study was to examine the differences in upper body power output among lineman and nonlineman division I collegiate football players and to examine the influence of 2 normalization procedures: (a) simple ratio scaling and (b) standardized allometric scaling. Ten lineman (mean +/- SD: age = 19.3 +/- 1.6 years; height = 187.7 +/- 4.7 cm; mass = 127.7 +/- 13.3 kg) and 14 nonlineman (19.6 +/- 1.4 years; 181.8 +/- 5.2 cm; 92.3 +/- 10.6 kg) performed a multiple repetition bench press power test at 50% of their 1 repetition maximum. Peak power (PP) was determined from a Tendo weightlifting analyzer that was attached to the barbell. The PP values were then analyzed under 3 conditions that included: (a) no scaling (absolute values), (b) ratio scaling (PP body mass), and (c) allometric scaling (PP body mass). The results indicated that the larger lineman demonstrated greater absolute PP values (p = 0.02); however, ratio scaling favored the smaller nonlineman group (p = 0.04). There were no differences in PP values between positions after the standardized allometric scaling procedure (p = 0.60). These findings indicated that the standardized allometric scaling procedure may be a more effective method for normalizing PP values among elite division I collegiate football players.

Assessment of the effectiveness of a sublingual, ergogenic spray on muscle strength and power.

Nutrients, chemicals, and drugs may be applied sublingually to provide faster absorption. Sublingual absorption occurs when a substance comes in contact with the buccal mucosa, where it diffuses through a membrane of the dense capillaries. The purpose of this study was to assess the effectiveness of a sublingual, ergogenic product containing vitamins, minerals, amino acids, and a coenzyme on muscle performance. National Collegiate Athletic Association Division I linemen (n = 23) voluntarily participated in the study. All participants (20.11 +/- 1.45 years, 132.1 +/- 9.85 kg, 191.19 +/- 3.85 cm) were tested on 102.1 kg (225 lb) bench press repetitions, vertical jump, and grip strength. One week later, participants were either a placebo or the experimental treatment before they were tested again. Repeated-measures analyses of variance (ANOVAs) yielded a significant (p = 0.046) gain for the bench press. A Newman-Keuls post hoc test revealed a significant change in the treatment group but not in the placebo group. While the treatment group demonstrated greater improvement over the placebo group for each of the remaining variables, none were significant: vertical jump (p = 0.65) and grip strength (p = 0.74). The inconsistency of the results may be due to several factors. First, the spray may not be an ergogenic agent; second, the standardized dose may be too small for those weighing >or=290 lb and should be administered based on weight. Furthermore, the coenzyme and amino acids may not possess the molecular size, solubility, chemical stability, or hydrophilic character to be easily absorbed. Lastly, the data were generated by field tests and may not be sensitive enough to elicit subtle responses.

Assessment of the effectiveness of nontransdermal energy patches on muscle endurance and power.

Claims of recently developed energy patches suggest that organic nanoscale biomolecular "antennas" produced by L and D-stereoisomers resonate at frequencies in unison with molecules in the cells inducing electron flow to assists in recruiting calcium ions, allowing greater muscle fiber recruitment during muscle contraction. The purpose of the study was to assess the efficacy of energy patches in the performance of selected muscle power and endurance measures. After a 5-minute warm-up and stretch, 41 college varsity football players (age, 20.37 +/- 1.24 years; height, 169.91 +/- 7.44 cm; weight, 109.45 +/- 19.85 kg) were pre-tested on 102-kg maximal bench press repetitions, standing vertical jump, grip strength, peak torque, torque to body weight, total work, average power, and average torque as measured by 50 repetitions of leg extensions at 180 degrees .s. The following week, the players were randomly assigned the experimental or placebo patches. After placement of the patches, the participants again completed a 5-minute warm-up, followed by the identical pre-test protocol. Repeated-measures ANOVAs were used to compare resultant data. No significant group interaction effects were found between experimental and placebo patches for maximal bench press repetitions (p = 0.48), vertical jump distance (p = 0.39), grip strength (p = 0.29), total work (p = 0.26), torque to body weight (p = 0.05), average peak torque (p = 0.08), and average power (p = 0.05). A significant increase occurred in the experimental group for peak torque (p = 0.04). It was concluded that the energy patches significantly improved performance over placebo patches in one of the eight variables tested and registered near significance in two additional variables. However, inconsistency in overall results demands further studies to determine the reliability in improvement of performance in the presence of energy patches.