48760 research outputs found
Sort by
MAXIMIZING 3-POINT BASKETBALL SHOOTING ACCURACY: MARKERLESS MOTION CAPTURE ANALYSIS
No full textIn the modern game of basketball, long-distance shooting efficiency is one of the key performance parameters that differentiate winning from losing game outcomes on both amateur and professional levels of competition. PURPOSE: By using innovative testing methodologies, the purpose of the present study was to examine differences in biomechanical characteristics between proficient and non-proficient 3-point shooters. METHODS: Twenty-six recreationally active males (age = 22.4±5.4 yrs; hgt = 185.8±5.2 cm; wgt = 83.3±9.5 kg) volunteered to participate in the present study. After completing a standardized warm-up procedure, each participant attempted 10 non-consecutive 3-point shots (6.75 m) with 10-15 s rest interval between each attempt. A 3D markerless motion capture system (SwRI Enable, San Antonio, TX, USA) composed of 9 high-definition cameras (Sony, RXO-II, Tokyo, Japan) sampling at 120 Hz was used to analyze the biomechanical parameters of interest during preparatory (i.e., initial concentric movement) and release phases (i.e., time point of the ball release) of the shooting motion. Independent t-tests were used to examine statistically significant differences (p\u3c0.05) between proficient (n=11) and non-proficient shooters (n=15) and Hedge’s g to depict the effect size magnitudes. Participants who made \u3e50% of their 3-point shooting attempts were classified as proficient. RESULTS: Significant between-group differences were found in the stance width during the preparatory phase and hip angle during the release phase of the shooting motion, with both values being greater within the proficient group of shooters (Table 1). CONCLUSIONS: The findings of the present study indicate that proficient 3-point shooters tend to have a wider stance during the initial phase of the shooting motion (i.e., improved balance and greater stability) when compared to non-proficient shooters and keep the torso in near-vertical position at the time point of the ball release (i.e., no backward trunk lean). Thus, providing basketball players with cues that focus on addressing the aforementioned adjustments in shooting form may help optimize individual 3-point shooting accuracy as well as the overall team’s chances in securing the winning game outcome. Table 1. Descriptive statistics (mean and standard deviations), statistically significant differences, and effect sizes of the differences between proficient (n=11; \u3e50%) and non-proficient (n=15; \u3c50%) 3-point basketball shooters
BUILDING BETTER ATHLETES: STRENGTH TRAINING & BASKETBALL PERFORMANCE
No full textBasketball is one of the most popular sports played on various levels of international competition. The fast pace of play resulting in scoring opportunities every few ball possessions, rapid changes in score, and highly athletic motions make this sport appealing to a large audience. In order to properly respond to on-court playing demands (e.g., jumping, sprinting, change-of-direction, shuffling), basketball players need to possess a unique blend of physiological performance attributes, including strength, power, speed, agility, and anaerobic and aerobic capacity. Thus, the aim of this presentation is to: a) provide a brief summary of existing scientific evidence supporting the importance of strength training for optimizing on-court basketball performance, b) present findings from our recently conducted research studies focused on examining the relationship between maximal upper and lower body strength and basketball shooting performance, and c) provide directions for future research pertaining to bridging a gap in scientific literature and advancing training regimens directed towards optimizing on-court basketball performance
THE EFFECTS OF STRETCHING ROUTINES ON PARAMETERS OF EXERCISE PERFORMANCE
No full textPURPOSE: People who exercise want to know which warm-up stretching routine will provide the best results: static, dynamic, or a static-dynamic combination. METHODS: We tested how these warm-up routines affected VO2 max, hematocrit, and blood lactate. We used a metabolic cart and treadmill using the Bruce Treadmill Protocol (MPH) while wearing a VO2 mask that quantified oxygen levels in participants’ inhalations and exhalations. A capillary blood sample was taken to quantify lactate and hematocrit before the warm-up, after the warm-up, and after completion of the Bruce Treadmill Protocol. Each participant completed each of the three warm-up routines. RESULTS: Although we hypothesized the combination stretch routine would produce higher VO2 max and relatively no difference in blood lactate pre- and post-exercise, our results showed the dynamic stretch routine produced these results. The dynamic warm-up routine had the highest mean VO2 max (36.022 O2 mL/kg/min). The static and combo routines had lower VO2 max means of 33.63 O2 mL/kg/min and 33.79 O2 mL/kg/min respectively. The dynamic routine from baseline to post warm-up had a mean lactate increase of 10.6 mg/dL and the mean increase from post warm-up to post testing was 30 mg/dL. These mean lactate differences were -5.285 mg/dL and 45.71 mg/dL for the combination stretching and 1.69 mg/dL and 38.38 mg/dL for the static stretching. Additionally, the dynamic routine produced the greatest decrease in post-exercise hematocrit. However, it was noted that all three stretching protocols caused a post warm-up non-significant decrease in hematocrit. CONCLUSION: Based on the data collected above we recommend that prior to exercise people complete a dynamic stretching routine prior
ASSESSING MUSCULAR PERFORMANCE ACROSS THE MENSTRUAL CYCLE IN COLLEGIATE SOFTBALL PLAYERS
No full textPURPOSE: The menstrual cycle is characterized by fluctuations in estrogen and progesterone that may impact training performance in females. We investigated whether there were differences in muscular performance measures throughout the menstrual cycle in NCAA D1 softball players. METHODS: D1 softball athletes participated in this study (n = 11; 19 ± 1 yr). The initial visit assessed height, weight, body composition (InBody 770), resting metabolic rate (Parvo TrueOne 2400), and cycle history using the FLO app. Other visits occurred during their projected early-follicular (EF), ovulatory (OV), and mid-luteal (ML) phases for performance testing. Each visit participants rated current perceived fatigue, motivation, strength, and energy. Following a standardized warm-up, a countermovement jump (CMJ) on a force plate (SPARTA) and 3, 15-yard sprints using timing gates (Vald Smart Speed) were performed. Velocity characteristics (Vitruve) were then assessed through 3 maximal-effort back squats at 70% of their 1RM. Differences in the data collected between EF, OV, and ML were determined using a one-way, repeated measures MANOVA followed by Bonferroni post-hoc testing. All data are reported as mean ± standard deviation, and a was set at p ≤ .05. RESULTS: Maximal force (8.2% \u3e OV, 7.6% \u3e EF; N/kg), power (12.1% \u3e OV, 12.5% \u3e EF; W/kg), jump height (5.3% \u3e OV, 6.2% \u3e EF; m), and maximal velocity (2.6% \u3e OV, 3.4% \u3e EF; m/s) during the CMJ peaked during ML, though there was no significance (p \u3e .05). Time to max acceleration (4.1% \u3e ML, 9.0% \u3e EF; s), time to take-off (6.7% \u3e ML, 9.3% \u3e EF; s), and sprint time (2% \u3e ML and EF; s) peaked during OV, though there was no significance (p \u3e .05). Squat velocity (3.1% \u3e OV, 1.5% \u3e ML; m/s) peaked during EF, though there was no significance (p \u3e .05). CONCLUSION: Performance variables from a CMJ test were maximized during ML and OV, while squat velocity was maximized during EF. No statistical significance was observed. Further data collection will clarify the potential differences in these performance characteristics in female athletes throughout the menstrual cycle
TWITCH PROPERTIES, BUT NOT AEROBIC FITNESS ARE RELATED TO ELECTRICALLY STIMULATED CRITICAL TORQUE
No full textPrevious research has demonstrated a relationship between maximal strength and fatigue characteristics during exercise. Additionally, maximal strength has been shown to correlate to work performed above critical torque. Fiber type has also been shown to be predictive of critical power, but little is known about its relationship to critical torque. PURPOSE: The purpose of the present study was to examine relationships among aerobic training status, muscle twitch properties, fatigue rate, and critical toruqe during electrically stimulated exercise. METHODS: Twenty individuals participated, 10 were aerobically trained and 10 were sedentary. A VO2 peak test was performed on a cycle ergometer. Participants then performed an electrically stimulated critical torque test at a starting torque of 25% of their maximum voluntary contraction. Stimulation frequency was set at 100 Hz and contractions occurred at a duty cycle of 2:2. In addition to critical torque, dependent measures included the initial rate of fatigue (the slope of decline over the initial 10 contractions), rate of force development and rate of force relaxation. Independent t-tests were used to compare outcome measures between trained and untrained groups and Pearson correlation coefficients were calculated to examine relationships among dependent measures. RESULTS: The trained and sedentary group differed in VO2 peak (54.3 ± 6.2 vs. 35.7 ± 4.6 ml·kg-1·min-1; p \u3c 0.001). No differences were found in stimulated critical torque (36.5 ± 11.1 vs. 33.6 ± 12.2% of starting torque; p = 0.58), slope of torque decline (0.48 ± 0.23 vs 0.46 ± 0.24; p = 0.90), rate of force development (275 ± 137 vs 250 ± 65 Nm·s-1; p = 0.63) and rate of force relaxation (179 ± 86 vs 173 ± 44 Nm·s-1) between groups. A significant relationship was found between starting torque and critical torque (r = -0.66; p \u3c 0.05), rate of torque of development and critical torque (r = -0.42; p \u3c 0.05) and rate of torque relaxation and critical torque (r = -0.66; p \u3c 0.05). Additionally, the slope of torque decline was also correlated with starting torque (r= 0.77;
WILL BODY FAT PERCENTAGE BE AFFECTED ACROSS A COMPETITIVE SOCCER SEASON?
No full textBody fat percentage is a critical metric that measures an individual’s body fat relative to their total weight. It is a key factor in determining overall health/well-being and fitness levels. This is why maintaining a healthy body fat percentage is vital in consistently progressing in a healthy lifestyle and physical fitness. PURPOSE: The purpose of this study is to evaluate the body fat percentage of female collegiate soccer players across their competitive in-season (August – November), and to see if playing status (starters, some playing time, no playing time) impacts one’s percentages. METHODS: The procedure to record body fat percentage on female collegiate soccer players was conducted using the Three-site body fat test, also known as the Skinfold test. When performing this test we measured at three sites. The back of the tricep, ASIS of the hip, and the thigh. All measurements were assessed by an experienced tester, and all measurements occurred on the right-hand side of the body. Five starters (age= 20.60 ±1.67 years, height 163.22cm ± 4.68 cm, mass 58.86kg ± 4.05kg, time played 44,412 s ± 12,675.60 s), four some playing time (age= 18.50 ±0.58 years, height 168.73 cm ± 7.74 cm, mass 65.10 kg ± 6.82kg, time played 16,710 s ± 7,060.20 s), four no-playing time (age= 19.00 ±1.41 years, height 166.70 cm ± 3.90 cm, mass 65.48 kg ± 8.50 kg, time played 5,295 s ± 6,707.4 s) volunteered to participate in the study. A Friedman’s non-parametric was used to assess body fat percentage differences across three time-points. An alpha of 0.05 was used for level of significance. RESULTS: The present findings observed no significant differences across the season or between the groups ( Starters p = .549, some playing time p = .368 and no playing time p =.779). CONCLUSION: The present study aimed to see if the body fat percentage of collegiate female soccer players was affected by playing time over the course of the season. Based upon the three times we assessed the athletes: (baseline middle August), first week of the season (early September) and the last assessment 6th week of the season (middle of October) the results suggest no significant differen
NEUROMUSCULAR RESPONSES DURING DYNAMIC RESISTANCE EXERCISE IN THE EXTREME AND SEVERE INTENSITY DOMAINS
No full textIntensity domains (moderate, heavy, severe, extreme) are demarcated by distinct physiological responses for whole-body dynamic exercise, but are not clearly defined for dynamic constant external resistance exercise. Neuromuscular efficiency (NME) and electromyographic amplitude (AMP) may provide insight on physiological responses during fatiguing resistance exercise across intensity domains. PURPOSE: To examine the neuromuscular responses during severe (SEV; \u3e2 min) and extreme (EXT;min) resistance exercise. METHODS: Ten participants (22 ± 1 yrs) performed a 1 repetition maximum (1RM) and repetitions to failure at 10% 1RM (SEV; 85 ± 38 reps) and 70% 1RM (EXT; 9 ± 4 reps) for single-limb leg extension, on separate days. AMP was measured from the vastus lateralis and normalized as a percent of 1RM. NME was calculated as the ratio between load (kg) to AMP (%1RM). Comparisons across time (First, Middle, and Last 10% of repetitions completed) were made using one-way repeated measures ANOVAs for SEV and EXT intensities. RESULTS: For SEV, AMP increased (First: 31.9 ± 19.7% \u3c Middle: 53.9 ± 31.0% \u3c Last: 92.1 ± 63.6%; p ≤ 0.035) and NME decreased (First: 0.665 ± 0.37 kg/% \u3e Middle: 0.375 ± 0.19 kg/% \u3e Last 0.23 ± 0.15 kg/%; p ≤ 0.011) across each timepoint. For EXT, AMP increased from the First (95.6 ± 57.6%) to Last 10% (128.4 ± 60.5%, p \u3c 0.001) but not from the First to Middle 10% (116.31±49.3, p = 0.111) or from the Middle to Last 10% (p \u3c 0.001). NME for EXT decreased from the First (1.46 ± 0.6 kg/%) to Middle 10% (1.14 ± 0.5 kg/%, p = 0.02), but did not change from the Middle to Last 10% (1.03 ± 0.4 kg/%, p = 0.064). CONCLUSION: For SEV, AMP increased and NME decreased during the initial stage of leg extension exercise and as task failure approached. For EXT, AMP did not change and NME was reduced during the initial stage of exercise. As leg extension exercise reached task failure, both AMP and NME did not change for EXT
THE INFLUENCE OF PROLONGED STANDING ON THORAX AND PELVIS INTERSEGMENTAL COORDINATION DURING GAIT
No full textPURPOSE: The lumbar spine plays a pivotal role in gait by allowing coordinated movements between the thorax and pelvis. Individuals with persistent low back pain (LBP) have higher in-phase thorax/pelvis coordination, potentially to reduce lumbar spine movement and prevent pain. Although people can develop pain during everyday tasks, such as prolonged standing, most studies include participants with pre-existing LBP. This study assessed how prolonged standing-induced LBP influences thorax/pelvis coordination during gait. METHODS: 34 participants (22 female) aged 18–40 were recruited for this study. Participants walked six times at a self-selected speed through a markerless 3D motion capture volume that measured whole-body kinematics before standing for 75 minutes while working at a computer and then walked again. During standing and after the final walking trial, participants filled out a 100 mm visual analog scale (VAS) to rate their LBP from “no pain at all” to “worst pain imaginable.” Exceeding 10 mm from baseline denoted pain development (PD). Triaxial pelvis/thorax coordination for the first 10 gait cycles before and after standing was analyzed using continuous relative phase mean and standard deviation (SD). Two-way ANOVA analyses were run with a between factor of pain group and within factor of time (pre-/post-standing). RESULTS: Ten people developed LBP while standing with a mean VAS of 26.4 [±15.2] mm (non-PDs=0.46 [±1.4] mm). After post-standing walking, pain was 17.2 [±16.9] mm for PDs. There was a significant interaction between pain group and time for axial twist (p=.021) and flexion-extension (p=.037) SD angle. While the magnitude of axial twist SD increased across participants after standing, SD was higher for PDs (26.1o[8.8o]; non-PDs=23.0o[8.2o]). The opposite was found for flexion-extension SD angle (PDs=43.7o[±4.7o]; non-PDs=47.4o[±3.8o]). CONCLUSION: Increased axial twist SD angle with prolonged standing-induced LBP is opposite to what is found for those with LBP. Prolonged standing-induced LBP may result in individuals exploring movement patterns when walking to reduce pain and discomfort. This may be supported by their reduced LBP VAS after walking. Future work will investigate ho
COGNITIVE REAPPRAISAL IMPROVES DAILY TIME TO EXHAUSTION CYCLING PERFORMANCE
No full textCognitive Reappraisal (CR) is a technique of reframing your perception of a negative stimulus towards a positive outlook. In relation to exercise, CR can modify one’s emotions or feelings towards exercise by reframing their perception to focus on the benefits of exercise, rather than pain or exhaustion. PURPOSE: This study examined the effects of cognitive reappraisal on exercise performance during time to exhaustion (TTE) trials. METHODS: Sixteen participants completed a single-blinded, randomized controlled study. Participants performed an eight-minute functional threshold power (8-FTP) cycling test to collect their average power output (POAVG). TTE trials were conducted daily Mon-Fri. During TTE trials, participants cycled as long as possible while maintaining 90-100% of their POAVG from their FTP. Participants were blinded to time, cadence, and other variables except for power output. A final FTP test was completed after all TTE trials. The control (CON) group, received constant motivation to complete the TTE, and the intervention group was taught CR on day 1 and was continuously, reminded to reframe their negative emotions during exercise to positive ones. A five x two ANOVA (time [2, 3, 4, 5, 6] × condition [CR, CON]) was used to determine differences in the day-to-day performance of the TTE. RESULTS: There was a significant time x condition interaction (F(1,15)=3.212, p=0.050, η_p^2=0.517) indicating that CR improved the participants TTE from visit 2 to 6. Post hoc analysis indicates the intervention group showed significant improvements in endurance time compared to control, during TTE 3 (270.4± 125.1 s, p=0.047) and TTE 5 (465.8± 195.5 s, p=0.031). Significant increases within the intervention group were observed from TTE 1 (815.1 s) to TTE 5 (1245.9 s, p=0.044; , η_p^2=0.533). CONCLUSION: Cognitive reappraisal positively impacts exercise performance, with the intervention group demonstrating significant improvements in TTE across multiple trials compared to the control group. These findings suggest that cognitive reappraisal could positively impact one’s ability to perform better by increasing endurance time during aerobic exercise
EFFECTS OF ANOREXIA NERVOSA ON MUSCLE QUALITY FOLLOWING LONG TERM RECOVERY IN RATS
No full textAnorexia nervosa (AN) is physiological and psychological disorder characterized by reduced nutrient intake leading to a decrease in fat and muscle area. A decrease in muscle area increases risk of musculoskeletal injuries and fractures contributing to higher health care costs. There have been limited studies on the long-term effect of AN following weight recovery. PURPOSE: Compare muscle health between simulated AN and subsequent long-term recovery and control rats over a two month recovery period. METHODS: Female Sprauge Dawley rats (age=8 weeks, n=15) underwent simulated AN for 30 days by decreasing their food consumption by ~50-60%. Afterwards, rats were allowed unrestricted access to food, simulating recovery. Ad libitum fed rats served as controls (CON, n=15). Peripheral quantitative computed tomography (PQCT) was used to image muscle cross-sectional area from both CON and AN rats at various recovery time points. Data was analyzed by comparing CON and AN at various time points with pre-planned T-tests. Significance was denoted at