Sprint Interval Training on Stationary Air Bike Elicits Cardiorespiratory Adaptations While Being Time-Efficient.

ABSTRACT: Moghaddam, M, Cervantes, M, Cheshier, B, and Jacobson, BH. Sprint interval training on stationary air bike elicits cardiorespiratory adaptations while being time-efficient. J Strength Cond Res 37(9): 1795-1801, 2023-Sprint interval training (SIT) refers to a set of brief intermittent exercises that are performed at maximal intensity. This study compared the effects of 2 SIT protocols (e.g., 10-5-SIT and 20-10-SIT) vs. moderate-intensity continuous training (MICT) on cardiovascular adaptations, using stationary air bikes. Thirty-two recreationally active individuals were randomly assigned to the 3 performance groups, such as 10-5-SIT (n = 11), 20-10-SIT (n = 10), and MICT (n = 11), to train 3 days per week for 4 weeks. Moderate-intensity continuous training included 30 minutes of cycling at 75% of maximal heart rate reserve, whereas the SIT protocols consisted of 3 sets of 8 intervals at all-out intensity. The 10-5-SIT and 20-10-SIT were performed with 10-second work:5-second rest and 20-second work:10-second rest, with 2.5- and 5-minute recovery periods between sets, respectively. A ramp protocol was used before and after the intervention via cycle ergometer to assess aerobic performance. Time to exhaustion (TTE), absolute V̇o2max (A-V̇o2max), relative V̇o2max (R-V̇o2max), and metabolic equivalents (METs) were measured and analyzed with 2-way mixed factorial analyses of variance (ANOVAs). In addition, total work (TW) during 12 sessions were recorded and analyzed with 1-way ANOVA. Significant (p < 0.05) differences were found for TW (10-5-SIT: 907.3 ± 332.0, 20-10-SIT: 1230.0 ± 188.1, and MICT: 2263.0 ± 896.9 calories) between groups. A significant main effect of time was observed for 10-5-SIT, 20-10-SIT, and MICT (p < 0.05) in TTE (increased by 7.3, 8.7, and 8.2%), A-V̇o2max (increased by 13.0, 11.8, and 13.6%), R-V̇o2max (increased by 12.6, 12.1, and 14.8%), and METs (increased by 12.7, 12.3, and 14.9%), respectively. Despite less volume and duration, both SIT protocols induced cardiorespiratory adaptations similar to MICT. These findings suggest that performing SIT on a stationary air bike is valuable because of time-efficiency and cardiorespiratory adaptations.

Mattress Coil Spring Fatigue and Weight-Bearing Support: Comparison of Weight-Bearing and Non-Weight-Bearing Springs.

OBJECTIVE: The purpose of this study was to compare the firmness of used mattress coil springs from the areas bearing greatest body weight versus areas subjected to little compression. METHODS: Weight-bearing springs (WBS) extracted from the center of the mattresses (N = 32), and non-weight-bearing springs (NWBS) extracted from the head/foot were of the same mattresses. To determine spring weakness, a 1296-g ingot was placed on the coil, and the compression distance was measured (cm). In addition, a gauge was used to measure the amount of pressure required to compress the coil springs a distance of 2 cm. Comparison between WBS and NWBS data were statistically treated using independent t tests and a 1-way analysis of variance. RESULTS: There were no significant group differences in weight or height in unloaded coils. However, there were significant (P < .05) differences in coil spring compression distance under load (WBS = 2.78 ± 0.34 cm; NWBS = 1.52 ± 0.39 cm) and force gauge compression (WBS = 1090.51 ± 88.42 g; NWBS = 1213.12 ± 71.38 g) between groups. CONCLUSION: This study found that WBSs were weaker when compressed than the NWBS from used mattresses, and such characteristics may not be visually apparent in a mattress when not in use. Thus, coil springs in bedding systems may eventually fail to provide the initial structural support after use. Such sagging may compromise sleep posture with accompanying poor sleep quality and quantity.

Kinanthropometric Characteristic Comparisons of NCAA Division I Offensive and Defensive Linemen Spanning 8 Decades.

ABSTRACT: Jacobson, BH, Dawes, J, Smith, D, and Johnson, Q. Kinanthropometric characteristic comparisons of NCAA Division I offensive and defensive linemen spanning eight decades. J Strength Cond Res 36(12): 3404-3408, 2022-College football players have gained body mass, stature, and speed since the inception of the game. Of particular note is the body mass gain of NCAA Division I offensive linemen (OL) and defensive linemen (DL). The primary purpose of this study was to compare body mass and stature of OL and DL for each decade since 1950 and to subsequently compare speed using more recently available NFL Combine data to determine if the rates of gain have been consistent or is waning. Ten universities were randomly chosen from the "Power Five" conferences based on the prominence of their football programs. Recorded data included players' body mass, stature, and available 40 yd times. For each team, 8 OL and 8 DL were chosen, totaling 80 OL and 80 DL. Results indicated that body mass increased significantly ( p < 0.05) for both OL and DL (57.9 and 54.4%, respectively). However, the rate of weight gain for either OL or DL was not linear. Both OL and DL consistently increased in height from 1950 with OL and DL increasing 12.7 cm (5.0 in) and 11.4 cm (4.7 in), respectively. In addition, 40 yd times have improved over the 3 available decades (2000-2020). The 2020 times were significantly faster than the 2000 for both OL and DL. These findings may have profound implications related to player safety. The overall increases in body mass of linemen in combination with greater speed may result in have devastating consequences to the human body in a contact/collision sport such as football. Indeed, new rules are being considered to reduce debilitating injures.

The Impact of Aquatic Based Plyometric Training on Jump Performance: A Critical Review.

There is evidence to suggest that aquatic plyometric training (APT) may be an effective and safer alternative to traditional land-based plyometric training (LPT) when training to increase jump performance. The aim of this review was to critically examine the current literature regarding the effects of APT vs. LPT on jump performance in athletic populations. Key terms were employed in five separate databases to complete the current review. Available articles were screened for inclusion and exclusion criteria to determine which studies were deemed eligible for review. Outcome measure in these studies included those assessing lower extremity power and jump performance (i.e., drop jumps, broad jumps, sergeant jumps, repeated countermovement jumps, and vertical jumps). All but one of the studies included in this critical review showed significant improvements in jump performance after LPT and APT interventions. Both LPT and APT groups experienced similar increases in jump performance and lower-body power, pre- to post-test, in the majority of the studies examined in this review. LPT and APT have the ability to improve lower extremity explosive strength and jump performance within athletic populations. Improvements in lower body power may improve overall athletic performance. Observations from this review may be used by sport coaches, strength coaches, and athletes alike to weigh the pros and cons of both forms of plyometric training. Observations from this review may also be used to weigh the pros and cons of APT over LPT in terms of reducing risk of injury.

Similar Anaerobic and Aerobic Adaptations After 2 High-Intensity Interval Training Configurations: 10:5 s vs. 20:10 s Work-to-Rest Ratio.

ABSTRACT: Moghaddam, M, Estrada, CA, Muddle, TWD, Magrini, MA, Jenkins, NDM, and Jacobson, BH. Similar anaerobic and aerobic adaptations after 2 high-intensity interval training configurations: 10:5 s vs. 20:10 s work-to-rest ratio. J Strength Cond Res 35(6): 1685-1692, 2021-This study compares the effects of 2 high-intensity interval training (HIIT) configurations, a 10-5 vs. a 20-10 second work-to-rest ratio, on anaerobic and aerobic performance. Thirty-four individuals were randomly assigned to 10-5-HIIT (n = 17) and 20-10-HIIT (n = 17) groups to complete 6 cycles of 6 exercises, 3 days a week for 4 weeks. The 10-5-HIIT was performed with 10 s:5 s work-to-rest ratio with 1-minute recovery between cycles, while the 20-10-HIIT was performed with 20 s:10 s work-to-rest ratio followed by a 2-minute recovery. Anaerobic (i.e., peak power [PP], anaerobic capacity [AC], anaerobic power [AP], and total work [TW]) and aerobic fitness (i.e., time to exhaustion [TE], absolute V̇o2max [A-V̇o2max], relative V̇o2max [R-V̇o2max]) were measured with pre-training and post-training intervention. A significant main effect time was observed for both 10-5-HIIT and 20-10-HIIT (p < 0.05) in PP (9.2%, 5.7%); AC (14.9%, 8.6%); AP (9.0%, 6.2%); TW (15.1%, 8.5%); TE (4.3%, 5.5%); A-V̇o2max (9.4%, 8.9%); R-V̇o2max (8.5%, 8.2%), respectively. In conclusion, individuals may be able to achieve similar health benefits as 20-10-HIIT by performing 10-5-HIIT, despite exercising for 50% less total time. High-intensity interval training has been suggested as a "time-efficient" mode of exercise that can mitigate the most significant barrier to physical activity, "lack of time." Both 10-5-HIIT and 20-10-HIIT can induce performance adaptations to a similar extent. However, because of shorter time commitment, performing 10-5-HIIT at 10 s:5 s work-to-rest ratio may offer a shorter and equally efficient interval. Functional fitness training during HIIT protocols seems to be as beneficial as ergometer-based HIIT to improve anaerobic and aerobic performance.

Muscular morphological adaptations of two whole-body high intensity interval training configurations.

BACKGROUND: High-intensity intermittent training (HIIT) has increased in popularity due to being time-efficient mode of exercise. Previous HIIT studies have mainly focused on percentage of fat loss, fat mass loss, and weight loss. However, enhancing muscle protein synthesis induced by HIIT that results in muscular morphological adaptations is a potential benefit of HIIT. This study compared the effects of two HIIT protocols on muscular morphological adaptations. METHODS: Thirty-four recreationally active participants were randomly assigned to 10-5-HIIT and 20-10-HIIT to complete 6 sets of 6 intervals. The 10-5-HIIT and 20-10-HIIT protocols were performed with 10s:5s and 20s:10s exercise-to-rest ratios and provided with 1- and 2-min recovery periods between sets, respectively. Muscle cross-sectional area (mCSA) and echo intensity (EI) of the rectus femoris (RF) and vastus lateralis (VL) were assessed via B-mode ultrasonography before and after intervention. Two-way mixed factorial ANOVAs were used for analyses. RESULTS: The 10-5-HIIT and 20-10-HIIT groups significantly (P<0.05) increased RF mCSA (change (Δ)=0.4±0.8 cm2, 8.0%; Δ=0.5±0.8 cm2, 5.5%) and VL mCSA (Δ=1.2±1.6 cm2, 9.0%; Δ=2.20±1.4 cm2, 10.4%), respectively. No significant (P>0.05) change was observed for the EI of the RF and VL. CONCLUSIONS: Whole-body HIIT can be a time-efficient exercise modality to elicit muscular morphological adaptations in the RF and VL muscles. The 10-5-HIIT protocol induced benefits comparable to those of the 20-10-HIIT, while it reduced the total exercise time by 50%.

Global Positioning System Monitoring of Selected Physical Demands of NCAA Division I Football Players During Games.

Bayliff, GE, Jacobson, BH, Moghaddam, M, and Estrada, C. Global positioning system monitoring of selected physical demands of NCAA Division I football players during games. J Strength Cond Res 33(5): 1185-1191, 2019-Global positioning system (GPS) tracking of athletes in selected sports is a new innovation into obtaining comprehensive data regarding physical output with respect to distance travelled (DT), acceleration, and change of direction. The purpose of this study was to determine selected physical demands of American football players during the course of games and to compare such data by player position. Offensive lineman (OL) (n = 14) and defensive lineman (DL) (n = 9) and offensive wide receivers (WRs) (n = 10) and defensive backs (DBs) (n = 10) were fitted with GPS monitors during games. Collected data included DT, maximum velocity (MV), and acceleration (AC), deceleration (DC) distance at 2 intensities. Results indicated that DBs travelled significantly (p < 0.05) greater distances than OL and WR, but not DL. For MV, DBs and WRs were not significantly different but were significantly different from OL and DL. Also, DL was significantly different than OL. For the most intense acceleration (3-10 m·s), WR accelerated significantly further than all other positions and DBs accelerated further than DL and OL. There was not significant difference between DL and OL. For deceleration at the high-intensity measure, significant differences existed among all positions. Underestimation of workload during games could be a factor for the overuse and soft-tissue injuries and more serious injuries. Furthermore, using GPS tracking of similar variables as found in this study may benefit coaches and trainers in many other high-intensity sports.

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.

Acute Effects of Deep Tissue Foam Rolling and Dynamic Stretching on Muscular Strength, Power, and Flexibility in Division I Linemen.

Behara, B and Jacobson, BH. Acute effects of deep tissue foam rolling and dynamic stretching on muscular strength, power, and flexibility in Division I linemen. J Strength Cond Res 31(4): 888-892, 2017-A recent strategy to increase sports performance is a self-massage technique called myofascial release using foam rollers. Myofascial restrictions are believed to be brought on by injuries, muscle imbalances, overrecruitment, and/or inflammation, all of which can decrease sports performance. The purpose of this study was to compare the acute effects of a single-bout of lower extremity self-myofascial release using a custom deep tissue roller (DTR) and a dynamic stretch protocol. Subjects consisted of NCAA Division 1 offensive linemen (n = 14) at a Midwestern university. All players were briefed on the objectives of the study and subsequently signed an approved IRB consent document. A randomized crossover design was used to assess each dependent variable (vertical jump [VJ] power and velocity, knee isometric torque, and hip range of motion was assessed before and after: [a] no treatment, [b] deep tissue foam rolling, and [c] dynamic stretching). Results of repeated-measures analysis of variance yielded no pretest to posttest significant differences (p > 0.05) among the groups for VJ peak power (p = 0.45), VJ average power (p = 0.16), VJ peak velocity (p = 0.25), VJ average velocity (p = 0.23), peak knee extension torque (p = 0.63), average knee extension torque (p = 0.11), peak knee flexion torque (p = 0.63), or average knee flexion torque (p = 0.22). However, hip flexibility was statistically significant when tested after both dynamic stretching and foam rolling (p = 0.0001). Although no changes in strength or power was evident, increased flexibility after DTR may be used interchangeably with traditional stretching exercises.

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.

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.

Combined Use of Alcohol and Energy Drinks Increases Participation in High-Risk Drinking and Driving Behaviors Among College Students.

OBJECTIVE: A recent study suggested that college students who combined alcohol and energy drinks were more likely than students who consumed only alcohol to drive when their blood alcohol concentration (BAC) was higher than the .08% limit and to choose to drive despite knowing they had too much alcohol to drive safely. This study sought to replicate those findings with a larger sample while also exploring additional variables related to impaired driving. METHOD: College students (N = 549) completed an anonymous online survey to assess differences in drinking and driving-related behaviors between alcohol-only users (n = 281) and combined alcohol-energy drink users (n = 268). RESULTS: Combined users were more likely than alcohol-only users to choose to (a) drive when they perceived they were over the .08% BAC limit (35.0% vs. 18.1%, p < .001), (b) drive despite knowing they had too much alcohol to drive safely (36.3% vs. 17.0%, p < .001), and (c) be a passenger when they knew the driver had too much alcohol to drive safely (44.1% vs. 23.6%, p < .001). Combined users were significantly more likely (p < .001) to report indicators of high-risk alcohol use, such as larger number of drinks consumed, number of days drinking, number of days drunk, number of heavy episodic drinking episodes, greatest number of drinks on one occasion, and average hours of consumption. CONCLUSIONS: Combined use of alcohol and energy drinks may place drinkers at greater risk when compared with those who consume only alcohol. College students in this sample who combined alcohol and energy drinks were more likely to participate in high-risk driving behaviors than those who consumed only alcohol.

A comparison of the combined-use of alcohol & energy drinks to alcohol-only on high-risk drinking and driving behaviors.

BACKGROUND: The combined-use of alcohol and energy drinks is an emerging public health issue. This investigation examined differences in drinking and driving behaviors among combined-users (CU) and participants who consumed alcohol-only (AO). OBJECTIVES: This study was specifically designed to investigate potential differences in drinker's perceptions of (a) what it means to them to drive over the .08 Blood Alcohol Content (BAC) driving limit and (b) what it means to drive after knowing they have had too much to drink to drive safely. METHODS: College students (N = 355) were surveyed to assess differences in drinking and driving-related behaviors between the AO (n = 174) and CU (n = 107) groups. RESULTS: CU were more likely than AO to drive over the .08 BAC driving limit (53% vs. 38%; p = .009) and after knowing they were too drunk to drive (57% vs. 44%; p = .025). CU were also more likely (56% vs. 35%; p = .000) to ride with an intoxicated driver while knowing it was unsafe. Conclusions/Importance: Combined-users are more likely to drive after drinking, drive while knowingly drunk, and participate in other high-risk behaviors such as heavy drinking that increase the potential for injury. Public policy makers and health professionals should focus prevention efforts to reduce high-risk combined-use behavior.

Increased Energy Drink Use as a Predictor of Illicit Prescription Stimulant Use.

BACKGROUND: The purpose of this study was to examine energy drink usage patterns and to investigate the relationship between energy drink use and illicit use of prescription stimulants among college students. METHODS: A sample of 605 undergraduate and graduate students (mean age±SD: 21.96±4.216) from a large midwestern university voluntarily participated in the study. RESULTS: Of the participants, 48.9% (n=296) reported using energy drinks in the past 30 days, whereas 25.3% (n=153) reported using prescription stimulant drugs in the past 30 days. Among prescription stimulant users without a valid medical prescription, Mann-Whitney U tests and logistic regression analysis revealed that the frequency of energy drink consumption was a significant predictor of illicit prescription stimulant use, with the odds for use increasing by 14% with each additional day of energy drink use (odds ratio for using=1.143, P≤.001). Analyses revealed statistically significant differences (P<.05) between prescription stimulant users and nonusers for all energy drink use variables, with the strongest predictors of prescription stimulant use being the number of days using energy drinks in the past 30 days and number of energy drink binges in the past 30 days. CONCLUSIONS: Results indicate that the frequency of energy drink use was a significant predictor of the illicit use of prescription stimulants.

Frequency of energy drink use predicts illicit prescription stimulant use.

BACKGROUND: The purpose of this study was to examine energy drink (ED) usage patterns and to investigate the illicit use of prescription stimulants among college students. METHODS: A sample of 267 undergraduate and graduate students (mean age of 22.48 among stimulant users) from a large midwestern university and its branch campus locations voluntarily participated in the study. RESULTS: Among prescription stimulant users without a valid medical prescription, Mann-Whitney U tests and logistic regression analysis revealed that the frequency of ED use was a significant predictor of the illicit use of prescription stimulants. Moreover, frequency of ED consumption was a significant predictor of the illicit use of prescription stimulant medications, with the odds for using increasing by .06 with each additional day of ED use past 0 day (odds for use = 1.06, P =.008). CONCLUSIONS: Results indicate that the frequency of ED use is a significant predictor of the illicit use of prescription stimulants. All prescription stimulant users with or without a valid script also used EDs. This finding is important to practitioners because of the harmful interactions (eg, serotonin syndrome) that can occur when ED ingredients (eg, ginseng, yohimbine, evodamine, etc) are mixed with prescription stimulants.

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.

Effect of whole-body vibration on delayed onset muscular soreness, flexibility, and power.

Delayed onset muscle soreness (DOMS) occurs after unaccustomed or intense bouts of exercise. The effects of DOMS peak at approximately 48 hours postexercise, and DOMS is treated, albeit not highly successfully, in a variety of ways including the use of medication and therapeutic modalities. The objective of this study was to determine the effects of whole-body vibration (WBV) on DOMS through Visual Analog Scale (VAS) measures of perceived pain/soreness and to assess the effect of WBV on flexibility and explosive power after induced DOMS. Twenty healthy college-aged participants (10 men and 10 women) volunteered for this study and were randomly assigned to the experimental or the control group. Participants completed baseline measures for VAS, hamstring and lower back flexibility, and explosive power before completing a DOMS-inducing exercise. Measures for VAS, hamstring and lower back flexibility, and explosive power were measured immediately postexercise and again immediately posttreatment. Participants reported back to the laboratory for 4 additional data collections sessions. Both the experimental and control groups yielded significant differences (p < 0.05) in pretest and posttest DOMS between baseline and pretest and posttest 1, pretest and posttest 2, and pretest and posttest 3. No significance (p > 0.05) was found within or between groups when comparing preassessments and postassessments of DOMS, flexibility, or explosive power. No differences (p > 0.05) between WBV and light exercise were found for DOMS, flexibility, and explosive power. These results suggest that WBV is equally as effective as light exercise in reducing the severity of DOMS. Thus, WBV may be used as a recovery option in addition to current treatments.

Assessment of the benefit of powered exercises for muscular endurance and functional capacity in elderly participants.

BACKGROUND: Aging is accompanied by a significant loss of strength which further contributes to loss of functional ability and a propensity for injury. The purpose of this study was to assess the effectiveness of power assisted exercises on muscle endurance and functional capacity of elderly participants following 12 weeks of supervised training. METHODS: Elderly subjects (N = 53) were randomly assigned to either the experimental or the control group. The experimental group trained for 12 weeks using powered exercise machines incorporating only concentric contractions while attempting to accelerate the preset, moving levers. Training involved 6 separate machines and using both upper- and lower-body musculature. Pre- and posttests consisted of Timed Chair Stand, Up and Go Test, arm curl, bench press, leg extension, triceps extension, and the Berg Balance Scale Assessment. RESULTS: Analysis yielded significant improvements (P < .05) by the experimental group over the control group in all measures of muscle endurance, balance, and functional capacity. An improvement in balance paralleled muscle endurance improvements. CONCLUSIONS: Powered exercise equipment when used actively, will generate both upper- and lower-body muscle endurance in elderly participants in a safe exercise environment and such improvement also generated improvement in balance.