Can Squat Jump Performance Differentiate Starters vs. Nonstarters in Division I Female Soccer Players?

Magrini, MA, Colquhoun, RJ, Sellers, JH, Conchola, EC, Hester, GM, Thiele, RM, Pope, ZK, and Smith, DB. Can squat jump performance differentiate starters vs. nonstarters in division I female soccer players? J Strength Cond Res 32(8): 2348-2355, 2018-Although soccer is predominately an endurance sport, high velocity movements may be an important indicator of athletic success. The purpose of this investigation was to establish whether squat jumps (SJs) can differentiate starters from nonstarters with a female collegiate division I soccer team. Eighteen female division I soccer athletes were separated into 2 groups: 9 starters (age: 19.5 ± 1.0; mass = 64.8 ± 11.5 kg; height = 167.5 ± 7.7 cm; games started = 18.2 ± 4.7; and minutes played = 1633.8 ± 478.2 minutes) and 9 nonstarters (age: 19.4 ± 1.4 years; mass = 63.3 ± 4.2 kg; height = 164.7 ± 6.8 cm; games started 0.7 ± 1.3; and minutes played 158.2 ± 269.3 minutes). Each athlete performed 3 maximal SJs at a starting knee angle of 110° without arm swing. Each participant's SJ height, mean power (MP), peak power (PP), mean velocity (MV), and peak velocity (PV) were measured during each attempt by a linear position transducer. No statistically significant differences (p ≥ 0.05) in MP and PP between the starters and nonstarters were observed. However, starters performed significantly better than nonstarters in SJ height (p = 0.002), MV (p = 0.025), and PV (p = 0.015). In addition, SJ height was strongly correlated with MV (r = 0.628) and PV (r = 0.647). These findings suggest that SJ height, MV, and PV may be important variables for discriminating differences between starters and nonstarters in division I female soccer athletes and a strong indicator of explosive performance.

Effect of Energy Drink Consumption on Power and Velocity of Selected Sport Performance Activities.

Jacobson, BH, Hester, GM, Palmer, TB, Williams, K, Pope, ZK, Sellers, JH, Conchola, EC, Woolsey, C, and Estrada, C. Effect of energy drink consumption on power and velocity of selected sport performance activities. J Strength Cond Res 32(6): 1613-1618, 2018-Energy drinks (ED) comprise a multibillion dollar market focused on younger, active, and competitive individuals. Marketing includes claims of improved alertness and performance. The purpose of this study was to assess power (W) and velocity (m·s) of a simulated, isolated forehand stroke (FHS), and a countermovement vertical jump (CVJ) before and after ingestion of a commercially available energy shot (ES) or a placebo (PL). Healthy college-aged men and women (N = 36) volunteers were randomly placed in the ES or PL. Before and 30 minutes after ingesting either the ES or PL, participants performed 3 FHSs and CVJs. Power and velocity of each performance was measured using a linear velocity transducer and the highest value for each measure was used for subsequent analysis. The ES group demonstrated a significant (p = 0.05) increase in velocity and W for the FHS, but not for the CVJ. All measures remained unchanged in the PL group for both, the FHS and CVJ. Females demonstrated a significant increase in velocity over males in FHS, but not in CVJ. It was concluded that while the dose of stimulants in the ES was adequate to improve performance of smaller muscle groups, it may not have been sufficient to affect the larger muscle groups of the lower legs which contribute to the CVJ. While the ES used in the present study contained a caffeine dosage within the NCAA limit and did improve performance for the upper body, it must be noted that there are health risks associated with ED consumption.

Effects of Energy Beverage Consumption on Pistol Aiming Steadiness in Law Enforcement Officers.

Monaghan, TP, Jacobson, BH, Sellers, JH, and Estrada, CA. Effects of energy beverage consumption on pistol aiming steadiness in law enforcement officers. J Strength Cond Res 31(9): 2557-2561, 2017-The popularity of energy drinks (EDs)/shots (ESs) has grown steadily over the years resulting in billions of dollars of sales annually. Energy drink marketing focuses on the improved performance and alertness and a reduction in fatigue. Although caffeine comprises one of the ingredients, it is not fully known how the combination of the many remaining active ingredients affects physical performance. The purpose of this study was to investigate the effect of a commercially available ES on pistol aiming steadiness. Subjects (N = 10) consisted of accredited police officers in the Midwest. A randomized, blinded, crossover design was used to evaluate the pistol aiming steadiness after the consumption of an ES or placebo. Pistol aiming steadiness was measured using a hole/stylus steadiness tester and laser attached to a training pistol before and 30 minutes after ES or placebo consumption. Analysis revealed that the ES significantly (p ≤ 0.05) impaired pistol steadiness, whereas the placebo yielded no significant difference in aiming steadiness. Based on these results, it was concluded that the consumption of an ES could compromise aiming accuracy and shot placement, thereby jeopardizing the health and welfare of law enforcement personnel.

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.

Potentiation: Effect of Ballistic and Heavy Exercise on Vertical Jump Performance.

Hester, GM, Pope, ZK, Sellers, JH, Thiele, RM, and DeFreitas, JM. Potentiation: Effect of ballistic and heavy exercise on vertical jump performance. J Strength Cond Res 31(3): 660-666, 2017-The purpose of this study was to compare the acute effects of heavy and ballistic conditioning protocols on vertical jump performance in resistance-trained men. Fourteen resistance-trained men (mean ± SD: age = 22 ± 2.1 years, body mass = 86.29 ± 9.95 kg, and height = 175.39 ± 9.34 cm) with an average relative full squat of 2.02 ± 0.28 times their body mass participated in this study. In randomized, counterbalanced order, subjects performed two countermovement vertical jumps before and 1, 3, 5, and 10 minutes after either performing 10 rapid jump squats or 5 heavy back squats. The back squat protocol consisted of 5 repetitions at 80% one repetition maximum (1RM), whereas the jump squat protocol consisted of 10 repetitions at 20% 1RM. Peak jump height (in centimeters) using a jump mat, along with power output (in Watts) and velocity (in meters per second) through a linear transducer, was recorded for each time interval. There was no significant condition × time interaction for any of the dependent variables (p = 0.066-0.127). In addition, there was no main effect for condition for any of the dependent variables (p = 0.457-0.899). Neither the ballistic nor heavy protocol used in this study enhanced vertical jump performance at any recovery interval. The use of these protocols in resistance-trained men to produce postactivation potentiation is not recommended.

Efficacy of a Ventilatory Training Mask to Improve Anaerobic and Aerobic Capacity in Reserve Officers' Training Corps Cadets.

The purpose of this study was to examine the efficacy of a ventilatory training mask to improve anaerobic and aerobic fitness in reserve officers' training corps (ROTC) cadets. Seventeen ROTC cadets from a Midwest university completed pre- and postassessments consisting of anthropometry, a 30-second Wingate Anaerobic Test (WAnT), and a maximal aerobic capacity test (V[Combining Dot Above]O2max). A 6-week intervention training period was used during which time participants completed their mandatory physical training (PT) sessions. Participants were randomly assigned to either the experimental group (MASK; n = 9) or the control group (CON; n = 8). The ventilatory training masks were adjusted to simulate an altitude of 2,750 m. There was no significant effect (p ≤ 0.05) between groups on fatigue index, anaerobic capacity, peak power, V[Combining Dot Above]O2max, or time to exhaustion. These results suggest that the use of the ventilatory training mask during mandatory PT did not elicit superior aerobic or anaerobic adaptations in ROTC cadets. Therefore, it is recommended that more established simulated altitude training methods be used when incorporating intermittent hypoxic training.

Longer Interset Rest Periods Enhance Muscle Strength and Hypertrophy in Resistance-Trained Men.

Schoenfeld, BJ, Pope, ZK, Benik, FM, Hester, GM, Sellers, J, Nooner, JL, Schnaiter, JA, Bond-Williams, KE, Carter, AS, Ross, CL, Just, BL, Henselmans, M, and Krieger, JW. Longer interset rest periods enhance muscle strength and hypertrophy in resistance-trained men. J Strength Cond Res 30(7): 1805-1812, 2016-The purpose of this study was to investigate the effects of short rest intervals normally associated with hypertrophy-type training versus long rest intervals traditionally used in strength-type training on muscular adaptations in a cohort of young, experienced lifters. Twenty-one young resistance-trained men were randomly assigned to either a group that performed a resistance training (RT) program with 1-minute rest intervals (SHORT) or a group that employed 3-minute rest intervals (LONG). All other RT variables were held constant. The study period lasted 8 weeks with subjects performing 3 total body workouts a week comprised 3 sets of 8-12 repetition maximum (RM) of 7 different exercises per session. Testing was performed prestudy and poststudy for muscle strength (1RM bench press and back squat), muscle endurance (50% 1RM bench press to failure), and muscle thickness of the elbow flexors, triceps brachii, and quadriceps femoris by ultrasound imaging. Maximal strength was significantly greater for both 1RM squat and bench press for LONG compared to SHORT. Muscle thickness was significantly greater for LONG compared to SHORT in the anterior thigh, and a trend for greater increases was noted in the triceps brachii (p = 0.06) as well. Both groups saw significant increases in local upper body muscle endurance with no significant differences noted between groups. This study provides evidence that longer rest periods promote greater increases in muscle strength and hypertrophy in young resistance-trained men.

The Long and Winding Road.

In this piece, I want to use the opportunity to acknowledge the Working Party on Sexual Misconduct in Surgery's report on sexual misconduct in surgical environments. I want to express the opinion that this sort of behaviour may well be only one facet of other negative issues occurring in these challenging and largely male-dominated areas; maybe in understanding this and relating it to the hierarchical competitive nature of the surgical training pathway, we can start to solve current problems and so prevent future ones?

Comparing current fitness center members' perceptions of the motivational climate with non-members.

Researchers using an achievement goal theory and caring climate framework have highlighted the connection between fitness center members' climate perceptions and their exercise motivation. However, much of what is known comes from current members, with little known about former and non-members' perceptions. The purpose of this study was to compare current, former, and non-members' perceptions of the motivational climate of a university campus fitness facility. Faculty and staff ( N = 657) at a large American university completed a one-time mixed-methods survey about their perceptions of the motivational climate (i.e. caring climate; preference for caring, task-, ego-involving climate), staff behaviors (i.e. caring, task involving), and usage of their campus fitness facility. Despite usage, quantitative analyses indicated that all participants reported valuing a caring, task-involving climate over a non-caring, ego-involving climate when choosing a fitness center. When asked about the particular fitness center for this study, current members were more likely than former and never users to perceive a caring climate where staff engaged in task-involving behaviors. Content analysis of the qualitative comments revealed that three main themes emerged with regard to perceptions and fell into positive, negative, and neutral categories. Overall, current users were more likely to perceive caring behaviors among the staff such as taking measures to welcome members and supporting their individualized goals. Former and never users were more likely to perceive staff as unhelpful, unwelcoming, and unfriendly. In an effort to remove barriers to physical activity, fitness professionals should consider how their behaviors, interactions, and promotional materials impact individuals' decision of whether to exercise at their fitness facility. The findings include a discussion for fitness staff to consider when creating advertisement and outreach efforts as well as how to foster the most effective climate to attract and retain exercisers.

Hostility and distraction have differential influences on cardiovascular recovery from anger recall in women.

This study investigated the relation of dispositional hostility to cardiovascular reactivity during an anger-recall task and of hostility and distraction to posttask recovery in 80 healthy women (ages 18-30). Half were randomly assigned to distraction during recovery. Hostility predicted slower systolic blood pressure and preejection period during recovery. Distraction was related to faster cardiac recovery, higher high-frequency (HF) power, lower low-frequency (LF) power and LF:HF ratios, and lower state anger and rumination during recovery. These results indicate deleterious influences of hostility on cardiovascular recovery but not during anger recall. The findings also show beneficial effects of distraction in expediting cardiovascular recovery, possibly through reducing rumination and anger.