THE EFFECTS OF SUSPENDED WEIGHT RESISTANCE ON AGILITY IN COLLEGIATE ATHLETES

Instability resistance training techniques are commonly used to increase athletic performance. The purpose of this study was to analyze the effects of performing the squat exercise with suspended weight within a six-week resistance training program on agility in collegiate male athletes. Thirty-two male collegiate baseball players were randomly assigned to a suspended or conventional resistance training group. They completed the T-test agility test before and after a six-week resistance training program. The suspended group had weight plates hanging below the barbell for the squat exercise. A repeated measures ANOVA was used to assess improvements in performance within groups and between groups. The T-test agility times for both groups significantly decreased from pre- to post-testing, but there were no significant differences between groups

Resting Energy Expenditure and Delayed-Onset Muscle Soreness After Full-Body Resistance Training with an Eccentric Concentration

The purpose of this investigation was to determine the effect of an acute bout of high-volume, full-body resistance training with an eccentric concentration on resting energy expenditure (REE) and indicators of delayed-onset muscle soreness (DOMS). Eight resistance trained (RT) and eight untrained (UT) participants (mean: age = 23.5 years; height = 180.76 cm; weight = 87.58 kg; body fat = 19.34%; lean mass = 68.71 kg) were measured on four consecutive mornings for REE and indicators of DOMS: creatine kinase (CK) and rating of perceived muscle soreness (RPMS). Delayed-onset muscle soreness was induced by performing eight exercises, eight sets, and six repetitions using a 1-second concentric and 3-second eccentric muscle action duration. A two-factor repeated-measures analysis of variance revealed that REE was significantly (p \u3c 0.05) elevated at 24, 48, and 72 hours post compared with baseline measures for both UT and RT groups. Ratings of perceived muscle soreness were significantly elevated within groups for UT and RT at 24 and 48 hours post and for UT only at 72 hours post compared with baseline (p \u3c 0.05). Nonparametric analyses revealed that CK was significantly increased at 24 hours post for both UT and RT and at 48 and 72 hours post for UT only compared with baseline (p \u3c 0.05). Resting energy expenditure and indicators of DOMS were higher in UT compared with RT on all measures, but no significant differences were determined. The main finding of this investigation is that full-body resistance training with an eccentric concentration significantly increased REE up to 72 hours postexercise in UT and RT participants

THE EFFECTS OF TWO DIFFERENT TYPES OF DYNAMIC WARM-UP AND STATIC STRETCHING ON POWER AND SPEED

Static stretching has often been found to decrease performance in power and speed activities, but dynamic warm-ups usually increase performance. We examined the effects of a mini-band warm-up, a medicine ball warm-up, and static stretching on 10m and 20m sprint times, as well as overhead medicine ball throw performance. Twenty-four Division I female soccer players completed the three warm-ups and a control 5 minute jog condition on separate days and were tested on the 10m and 20m sprint times and overhead medicine ball throw. ANOVA's and follow-up paired t-tests ( ~ ~ 0 . 0 5w)er e used to determine differences between the warm-ups. Significant differences were found between groups for the 1 Om sprint times but not for the 20m sprint times or the overhead medicine ball throw

Validity of Critical Velocity Concept for Weighted Sprinting Performance

International Journal of Exercise Science 11(4): 900-909, 2018. We investigated the validity of a recently developed equation for predicting sprinting times of various tactical loads based upon the performance of a running 3-min all-out exercise test (3MT). Thirteen recreationally trained participants completed the running 3MT to determine critical velocity (CV) and finite running capacity for running velocities exceeding CV (D’). Two subsequent counterbalanced loaded sprints of 800 and 1000 m distances with 20 and 15% of their body mass, respectively, were evaluated. Estimated times (t, sec) for running 800 and 1000 m with a tactical load was derived using t = (D – D’)/CV. Critical velocity adjusted for an added load using the following regression equation: original CV + (-0.0638 x %load) + 0.6982, D was 800 or 1000 m, and whole percentage load was ~15 or 20% of the participant\u27s body mass. From the 3MT, CV (3.80 ±0.5 m.s-1) and D’(200 ±49.88 m) values were determined.The typical error of predicting actual times for the 800 and 1000 m loaded sprints were 5.6 and 10.1 s, with corresponding ICCs of 0.95 and 0.87, and coefficient of variations of 2.9 and 4.3%. The effect size differences between estimated and actual sprint times were small (0.27) and moderate (0.60) for 800 and 1000 m, respectively. The adjustment to CV through the regression equation yields small to moderate overestimates of maximally loaded sprint times for distances of 800 and 1000 m. Whether such errors remain pervasive for prescribing high-intensity interval training is unclear and requires further investigation

The Effect of Static Stretching, Mini-Band Warm-Ups, Medicine-Ball Warm-Ups, and a Light Jogging Warm-Up on Common Athletic Ability Tests

International Journal of Exercise Science 13(4): 298-311, 2020. Proper warm-up is important for facilitating peak athletic performance and reducing injury risk; yet, warm-up procedures vary considerably amongst coaches and athletes. The purpose of this study was to assess the effect of a static stretching, medicine-ball, and mini-band warm-ups relative to a light jogging warm-up only on athletic ability test performance. It was hypothesized that static stretching would negatively affect performance, while medicine-ball and mini-band warm-ups would positively affect performance relative to light jogging only. Twelve female collegiate soccer players (19.3 ± 1.2y, 65.2 ± 7.5kg, 1.67 ± 0.07m) participated in this study. Athletes completed each warm-up protocol and all of the athletic performance tests over four sessions in a semi-randomized, counterbalanced order. An omnibus MANOVA with vertical jump height, medicine ball throw distance, 10m and 20m sprint time, and T-test time as the dependent variables was not significant indicating that warm up did not have an effect on subsequent athletic ability test performance [Wilks’ λ = 0.64, F(15,110) = 1.28, p= 0.23, η2= 0.14]. Static stretching warm-up did not negatively influence athletic potential compared to mini-band and medicine ball warm-ups, though the most optimal warm-up is likely athlete specific

The Metabolic Cost of a High Intensity Exercise Program During Bed Rest

Background: Given that disuse-related skeletal muscle atrophy may be exacerbated by an imbalance between energy intake and output, the amount of energy required to complete exercise countermeasures is an important consideration in the well being of subject health during bed rest and spaceflight. Objective: To evaluate the energy cost of a high intensity exercise program performed during short duration bed rest. Methods: 9 subjects (8 male and 1 female; 34.5 +/- 8.2 years) underwent 14 days of bed rest and exercise countermeasures. Exercise energy expenditure and excess post exercise oxygen consumption (EPOC) were collected once in each of 5 different exercise protocols (30 second, 2 minute and 4 minute intervals, continuous aerobic and a variety of resistance exercises) during bed rest. Body mass, basal metabolic rate (BMR), upper and lower leg muscle, subcutaneous, and intramuscular adipose tissue (IMAT) volumes were assessed before and at the end of bed rest. Results: There were no significant differences in body mass (pre: 75.1 +/- 10.5 kg; post: 75.2 +/- 10.1 kg), BMR (pre: 1649 +/- 216 kcal; post: 1657 +/- 177 kcal), muscle subcutaneous, or IMAT volumes (Table 2) after 14 days of bed rest and exercise. Body mass was maintained with an average daily intake of 2710 +/- 262 kcal (36.2 +/- 2.1 kcal/kg/day), while average daily energy expenditure was 2579 +/-311 kcal (34.5 +/- 3.6 kcal/kg/day). Exercise energy expenditure was significantly greater as a result of continuous aerobic exercise than all other exercise protocols

Integrated Resistance and Aerobic Training Maintains Cardiovascular and Skeletal Muscle Fitness During 14 Days of Bed Rest

Background: Known incompatibilities exist between resistance and aerobic training. Of particular importance are findings that concurrent resistance and aerobic training reduces the effectiveness of the resistance training and limits skeletal muscle adaptations (example: Dudley & Djamil, 1985). Numerous unloading studies have documented the effectiveness of resistance training alone for the maintenance of skeletal muscle size and strength. However the practical applications of those studies are limited because long ]duration crew members perform both aerobic and resistance exercise throughout missions/spaceflight. To date, such integrated training on the International Space Station (ISS) has not been fully effective in the maintenance of skeletal muscle function. Purpose: The purpose of this study was to evaluate the efficacy of high intensity concurrent resistance and aerobic training for the maintenance of cardiovascular fitness and skeletal muscle strength, power and endurance over 14 days of strict bed rest. Methods: 9 subjects (8 male and 1 female; 34.5 +/- 8.2 years) underwent 14 days of bed rest with concurrent training. Resistance and aerobic training were integrated as shown in table 1. Days that included 2 exercise sessions had a 4-8 hour rest between exercise bouts. The resistance training consisted of 3 sets of 12 repetitions of squat, heel raise, leg press and hamstring curl exercise. Aerobic exercise consisted of periodized interval training that included 30 sec, 2 min and 4 min intervals alternating by day with continuous aerobic exercise

Neither a Multi-Ingredient Pre-Workout Supplement nor Caffeine Were Effective at Improving Markers of Blood Flow or Upper-Body Resistance Exercise Performance

International Journal of Exercise Science 13(2): 167-182, 2020. Few studies have measured the effects of multi-ingredient pre-workout supplements on blood flow or heart rate variability or have compared a multi-ingredient pre-workout supplement to a matched single ingredient. This study examined the effects of a multi-ingredient pre-workout supplement, an equivalent amount of caffeine, and placebo on markers of resistance training performance, blood flow, blood pressure, and heart rate variability. The study utilized a randomized, placebo-controlled, repeated-measures, crossover design. Twelve resistance-trained males (22.75 ± 4.51 yrs; 183.4 ± 7.37 cm; 91.05 ± 17.77 kg) completed the study. Resistance exercise performance was defined as total work performed during elbow flexion and extension on an isokinetic dynamometer. Blood flow was calculated using time-averaged mean velocity and blood vessel diameter of the right brachial artery, which were measured via Doppler ultrasound. Heart rate was recorded using an electrocardiogram. Neither a multi-ingredient pre-workout supplement nor caffeine alone improved upper-body resistance exercise performance or markers of blood flow relative to placebo. No differences in heart rate variability were observed across treatments. A multi-ingredient pre-workout supplement was not effective at improving performance or blood flow and did not alter autonomic nervous system function

Willow Creek, California Tourism Analysis

The primary objective of this study was to introduce and recommend different strategies for the city of Willow Creek, California to increase tourism post-Covid-19. After extensive research, the report outlines various opportunities that the Recreation 365 class, Tourism Industry Management, believe will help Willow Creek in their efforts to attract their target audience

Novel Analog For Muscle Deconditioning

Existing models of muscle deconditioning are cumbersome and expensive (ex: bedrest). We propose a new model utilizing a weighted suit to manipulate strength, power or endurance (function) relative to body weight (BW). Methods: 20 subjects performed 7 occupational astronaut tasks while wearing a suit weighted with 0-120% of BW. Models of the full relationship between muscle function/BW and task completion time were developed using fractional polynomial regression and verified by the addition of pre- and post-flight astronaut performance data using the same tasks. Spline regression was used to identify muscle function thresholds below which task performance was impaired. Results: Thresholds of performance decline were identified for each task. Seated egress & walk (most difficult task) showed thresholds of: leg press (LP) isometric peak force/BW of 18 N/kg, LP power/BW of 18 W/kg, LP work/ BW of 79 J/kg, knee extension (KE) isokinetic/BW of 6 Nm/Kg and KE torque/BW of 1.9 Nm/kg. Conclusions: Laboratory manipulation of strength / BW has promise as an appropriate analog for spaceflight-induced loss of muscle function for predicting occupational task performance and establishing operationally relevant exercise targets