Comparisons between skeletal muscle imaging techniques and histology in tracking midthigh hypertrophic adaptations following 10 wk of resistance training.

This study had two aims. Aim1 was to determine the agreement between midthigh vastus lateralis (VL) cross-sectional area measured by ultrasound (mCSAUS) versus magnetic resonance imaging (mCSAMRI) at a single time point, and the ability of each to detect hypertrophic changes. Aim2 was to assess the relationships between pre- and posttraining changes in thigh lean mass determined by dual-energy X-ray absorptiometry (DXA), VL mCSAUS, ultrasound-determined VL thickness (VLThick), and VL mean myofiber cross-sectional area (fCSA) with changes in VL mCSAMRI. Twelve untrained males (age: 20 ± 1 yr, BMI: 26.9 ± 5.4 kg/m2; n = 12) engaged in a 10-wk resistance training program (2×/week) where right midthigh images and VL biopsies were obtained before and 72 h following the last training bout. Participants' VL mCSAMRI (P = 0.005), DXA thigh lean mass (P = 0.015), and VLThick (P = 0.001) increased following training, whereas VL mCSAUS and fCSA did not. For Aim1, mCSAUS demonstrated excellent concordance [concordance correlation coefficients (CCC) = 0.830] with mCSAMRI, albeit mCSAUS values were systematically lower compared with mCSAMRI (mean bias: -2.29 cm2). In addition, PRE-to-POST VL mCSA changes between techniques exhibited good agreement (CCC = 0.700; mean bias: -1.08 cm2). For Aim2, moderate, positive correlations existed for pre-to-post changes in VL mCSAMRI and DXA thigh lean mass (r = 0.580, P = 0.048), mCSAUS (r = 0.622, P = 0.031), and VLThick (r = 0.520, P = 0.080). A moderate, negative correlation existed between mCSAMRI and fCSA (r = -0.569, P = 0.054). Our findings have multiple implications: 1) resistance training-induced hypertrophy was dependent on the quantification method, 2) ultrasound-determined mCSA shows good agreement with MRI, and 3) tissue-level changes poorly agreed with mean fCSA changes and this requires further research.NEW & NOTEWORTHY This is the first study to comprehensively examine how different midthigh muscle imaging techniques and histology compare with one another in participants that performed 10 weeks of resistance training. Our study suggests that histology results show poor agreement with results yielded from other common muscle imaging techniques, and researchers should be aware of this limitation.

Functional Movement Screen Detected Asymmetry & Normative Values Among College-Aged Students.

BACKGROUND: The Functional Movement Screen (FMS™) is a popular test used by sports medicine professionals to identify dysfunctional movement patterns by analyzing mobility and stability during prescribed movements. Although the FMS™ has been a popular topic of research in recent years, normative data and asymmetries in college-aged students have not been established through research. PURPOSE: The objective was to determine normative FMS™ scores, report frequency counts for FMS™ asymmetries, and determine if the number of sports seasons and number of different sports an individual participated in during high school varied between university students that showed FMS™ identified asymmetries. STUDY DESIGN: Cross-sectional Study. METHODS: One hundred university students completed the FMS™ and an associated survey to determine which sport(s) and for how many seasons they participated in each sport(s) during high school. Total FMS™ scores were assessed as well as identifying the presence of an asymmetry during a FMS™ screen. An asymmetry within the FMS™ was defined as achieving an unequal score on any of the screens that assessed right versus left movements of the body. DATA ANALYSIS: Data analysis included descriptive statistics, Pearson correlation was utilized to investigate the relationship between number of sports played and number of sport seasons. Shapiro Wilk test for normality, and Mann Whitney U test was employed to investigate group differences in number of sports played. All analyses were conducted using SPSS software. RESULTS: Statistically significant correlations (r = .286, r2 = .08, p < 0.01) were found for both number of sport seasons and number of sports with FMS™ total score. In addition, participants without FMS™-detected asymmetries played significantly more seasons and more sports than their peers that presented asymmetries (U = 946.5, z = -1.98, p = 0.047). Finish with the actual p-value in parenthesis. CONCLUSION: Participating in multiple sports and multiple sport seasons during high school was associated with higher FMS™ total scores. Results suggest that participating in multiple sports and multiple sport seasons was associated with fewer asymmetries, which may decrease subsequent injury risk. LEVEL OF EVIDENCE: 3b.

Effect of Caffeine on Golf Performance and Fatigue during a Competitive Tournament.

PURPOSE: This study aimed to determine the effect of a caffeine-containing supplement on golf-specific performance and fatigue during a 36-hole competitive golf tournament. METHODS: Twelve male golfers (34.8 ± 13.9 yr, 175.9 ± 9.3 cm, 81.23 ± 13.14 kg) with a United States Golf Association handicap of 3-10 participated in a double-blind, placebo-controlled, crossover design in which they played an 18-hole round of golf on two consecutive days (36-hole tournament) and were randomly assigned to consume a caffeine-containing supplement (CAF) or placebo (PLA). CAF/PLA was consumed before and after nine holes during each 18-hole round. Total score, drive distance, fairways and greens in regulation, first putt distance, HR, breathing rate, peak trunk acceleration, and trunk posture while putting were recorded. Self-perceived ratings of energy, fatigue, alertness and concentration were also recorded. RESULTS: Total score (76.9 ± 8.1 vs 79.4 ± 9.1, P = 0.039), greens in regulation (8.6 ± 3.3 vs 6.9 ± 4.6, P = 0.035), and drive distance (239.9 ± 33.8 vs 233.2 ± 32.4, P = 0.047) were statistically better during the CAF condition compared with those during PLA. Statistically significant main effects for condition (P < 0.05) and time (P < 0.001) occurred for perceived feelings of energy and fatigue. Compared with PLA, CAF reported more energy (P = 0.025) and less fatigue (P = 0.05) over the competitive round of golf. There were no substantial differences in HR or breathing rates, peak trunk acceleration, or putting posture between conditions or over the round (P > 0.05). CONCLUSIONS: A moderate dose (1.9 ± 0.3 mg · kg(-1)) of caffeine consumed before and during a round of golf improves golf-specific measures of performance and reduces fatigue in skilled golfers.