Internal Training Load Measures During a Competitive Season in Collegiate Women Lacrosse Athletes

International Journal of Exercise Science 13(4): 778-788, 2020. Monitoring internal load provides useful and non-invasive markers of training stress and adaptation. However, the relationship between internal load measures across a competitive window remains inconclusive and limited. The purpose of this study was to report various internal load measures, as well as their relationship, across a season in Division I women lacrosse athletes (n = 20). Ultra-short natural logarithm of the root mean square of successive differences (lnRMSSD), salivary testosterone, cortisol, the testosterone:cortisol ratio, and self-reported measures of fatigue and recovery were collected weekly for 13 weeks. Means ± SD were calculated to provide descriptive values and a repeated measure analysis of variance (ANOVA) was used to analyze changes in testosterone, cortisol, testosterone:cortisol ratio (n = 8), and lnRMSSD (n = 8) over the course of the season. Pearson correlations assessed relationships between all internal load measures. No significant time effect was observed in testosterone (p = 0.059), cortisol (p = 0.544), testosterone:cortisol ratio (p = 0.120), or lnRMSSD (p = 0.062). lnRMSSD was correlated with testosterone (r = 0.265), cortisol (r = -0.232), testosterone:cortisol ratio (r = 0.345), and fatigue (r = -0.256) (p \u3c 0.05). More research is needed to examine relationships among markers of internal stress across all phases of the training cycle. Routine monitoring may help practitioners optimize training programming to reduce injury, illness, and overtraining

Foot-to-Foot Bioelectrical Impedance, Air Displacement Plethysmography, and Dual Energy X-ray Absorptiometry in Resistance-Trained Men and Women

International Journal of Exercise Science 11(4): 1145-1155, 2018. Accurate assessment of body composition is important to athletic performance goal setting and nutritional program design. Dual-energy x-ray absorptiometry (DXA) is considered the “gold standard” in body composition assessment, yet the cost renders DXA unfeasible for many. Therefore, it is of interest to compare other body composition assessment methods to DXA in resistance-trained individuals whose focus is athletic performance. The purpose of the current study was to determine the agreement in estimates of body composition ((body fat (BF%); fat mass (FM); fat free mass (FFM)) by bioelectrical impedance analysis (BIA; Tanita SC-331S) and air displacement plethysmography (ADP; BODPOD) compared to DXA (Hologic Horizon A) in 31 resistance-trained adults (men=15, women=16; mean±SD: 23.6±4.7years). Differences were found in BF% and FM between BIA and DXA. Regression analysis showed BF% and BMI to explain 24% and 29.9% of the variance in BF% measurements between DXA and BIA, respectively. The results of the Bland-Altman plot indicate a poor level of agreement between BIA and DXA for BF%, FM, and FFM (-4.56±8.82 %, -3.48±7.04 kg, 4.59±7.33 kg, respectively). ADP had wide limits of agreement for all variables (BF: 1.85±4.83 %, FM: 1.54±3.72 kg, FFM:-0.22±4.15 kg). BIA and ADP showed increasing variance in all measures as levels of fatness increased, with the exception of FFM for ADP. Compared to DXA, BIA overestimated BF% and FM, and underestimated FFM. Although wide individual errors were noted, no differences were found between ADP and DXA. The magnitude of inaccuracies between methods may be dependent upon individual body fatness

Relationships Among Metabolic-Risk, Body Fatness, and Muscular Fitness in Young Obese Latino Children

International Journal of Exercise Science 13(3): 488-500, 2020. Given the high prevalence of obesity in Latino children and potential health risks, the purpose of this study was to: 1) evaluate relationships among metabolic-risk, fitness, and body fatness; 2) determine sex differences in cardio-metabolic risk factors and fitness of obese children of Latino descent. Sixty children (boys, n= 39, 7.8 ± 1.5 years; girls, n= 21, 7.2 ± 1.5 years; body mass index, 97.8 ± 2.5thpercentile) completed assessments of height, weight, and body fat, prior to fasted blood draws and a battery of fitness tests. Cardio-metabolic markers were analyzed, and a metabolic risk score created. Correlations and regression analyses evaluated the relationships among body fatness, metabolic-risk, and fitness. Independent samples t-tests determined sex differences (p \u3c 0.05). Body fat related negatively to lower body power (p \u3c 0.016), but positively to upper body power (p= 0.049). After controlling for age and sex, body fat (p\u3c 0.001) was a positive predictor of variance in metabolic-risk scores, (R2 = 0.39, p \u3c 0.001). Further, the association between body fat and metabolic-risk was not moderated by sex. Metabolic-risk scores and body fat were similar for both sexes, but boys performed better on muscular fitness tests, even after accounting for fat free mass (p \u3c 0.05). Higher body fatness in obese Latino children may result in greater metabolic-risk and difficulty performing weight-bearing tasks. Therefore, culturally adapted weight management programs should employ a multifaceted approach to improve metabolic-risk and fitness

What Factors Predict Upper Body Push to Pull Ratios in Professional Firefighters?

International Journal of Exercise Science 13(4): 1605-1614, 2020. Shoulder joint injuries are common for professional firefighters. A potential cause of shoulder injury is an imbalance between anterior (push) and posterior (pull) shoulder joint musculature. Understanding what contributes to these imbalances may help to identify areas needing improvement. The purpose of this study was to investigate different push to pull (P2P) ratios and the relationships among common upper body fitness assessments, body composition, and push to pull (P2P) ratios in firefighters. Thirty-three professional firefighters completed the following testing protocol: one-repetition maximum (1RM) bench press, pull-up repetitions to failure, push-up repetitions to failure, and a body composition assessment. The endurance P2P (eP2P) was computed by dividing the number of push-up by pull-up repetitions, while strength P2P (sP2P) was the relative 1RM divided by pull-up repetitions. Bivariate relationships among variables were assessed with correlation coefficients and linear regression assessed association between eP2P and sP2P (p ≤ 0.05). The sP2P and eP2P were not associated (R2 = 0.032, p = 0.99). Strength P2P was related with bench press 1RM (r = 0.80) and push-ups (r = 0.40). Endurance P2P was related with pull-up repetitions (r = -0.62), body fat percentage (r = 0.40), and fat mass index (r = 0.34). The results of the present study suggest sP2P and eP2P ratios should not be used interchangeably. To improve sP2P and eP2P for firefighters, it is recommended to improve the strength of anterior and posterior upper body musculature, respectively, and reduce total body fat mass

The Effects of Accentuated Eccentric Loading on Barbell and Trap Bar Countermovement Jumps

This study examined effects of accentuated eccentric loading (AEL) on barbell and trap bar loaded countermovement jumps (LCMJ). Twenty-one subjects (16 male, 5 female; Age: 23.5 ± 1.8 years; Body mass: 81.4 ± 10.6 kg; Height: 176.9 ± 7.2 cm; Training age: 7.1 ± 2.6 years) participated in this study. Upon establishing one repetition maximum and baseline jumping conditions, three experimental loading sessions were completed in random order. Barbell and trap bar LCMJ were performed with a spectrum of fixed loads from 20-50 kg during control conditions and with additional AEL loads of 10, 20, or 30 kg for experimental conditions. According to coefficients of variation

The Effects of Body Tempering on Force Production, Flexibility and Muscle Soreness in Collegiate Football Athletes

There has been limited research to explore the use of body tempering and when the use of this modality would be most appropriate. This study aimed to determine if a body tempering intervention would be appropriate pre-exercise by examining its effects on perceived soreness, range of motion (ROM), and force production compared to an intervention of traditional stretching. The subjects for this study were ten Division 1 (D1) football linemen from Sacred Heart University (Age: 19.9 ± 1.5 years, body mass: 130.9 ± 12.0 kg, height: 188.4 ± 5.1 cm, training age: 8.0 ± 3.5 years). Subjects participated in three sessions with the first session being baseline testing. The second and third sessions involved the participants being randomized to receive either the body tempering or stretching intervention for the second session and then receiving the other intervention the final week. Soreness using a visual analog scale (VAS), ROM, counter movement jump (CMJ) peak force and jump height, static jump (SJ) peak force and jump height, and isometric mid-thigh pull max force production were assessed. The results of the study concluded that body tempering does not have a negative effect on muscle performance but did practically reduce perceived muscle soreness. Since body tempering is effective at reducing soreness in athletes, it can be recommended for athletes as part of their pre-exercise warmup without negatively effecting isometric or dynamic force production

Effect of Strength on Velocity and Power During Back Squat Exercise in Resistance-Trained Men and Women

The purpose was to examine load-velocity and load-power relationships of back squat in resistance-trained men (n = 20, 21.3 ± 1.4 years, 183.0 ± 8.0 cm, 82.6 ± 8.0 kg, 11.5 ± 5.0% total body fat) and women (n = 18; 20.0 ± 1.0 years; 166.5 ± 6.9 cm; 63.9 ± 7.9 kg, 20.3 ± 5.0% body fat). Body composition testing was performed followed by determination of back squat 1 repetition maximum (1RM). After at least 72 hours of recovery, subjects returned to the laboratory and completed 2 repetitions at each of 7 separate loads (30, 40, 50, 60, 70, 80, and 90% 1RM) in a random order. During each repetition, peak and average velocity and power were quantified using a commercially available linear position transducer. Men produced higher absolute peak and average power and velocity at all loads. When power output was normalized for body mass, significant differences remained. However, when normalizing for strength, no significant differences were observed between sexes. Furthermore, when subjects were subdivided into strong and weak groups, those above the median 1RM produced higher peak power, but only at loads greater than 60% 1RM. It was concluded that differences between men and women may be a result of strength rather than biological sex. Furthermore, training for maximal strength may be an appropriate method to augment maximal power output in those athletes who exhibit low levels of strength

Changes in Maximal Strength and Home Run Performance in Ncaa Division I Baseball Players Across 3 Competitive Seasons: A Descriptive Study

The purpose of this longitudinal, descriptive study was to observe changes in maximal strength measured via isometric clean grip mid-thigh pull and home runs (total and home runs per game) across three years of training and three competitive seasons for four National Collegiate Athletic Association (NCAA) Division 1 baseball players. A one-way repeated measures analysis of variance (ANOVA) was performed, revealing significant univariate effects of time for peak force (PF) (p = 0.003) and peak force allometrically scaled (PFa) (p = 0.002). Increases in PF were noted from season 1 to season 2 (p = 0.031) and season 3 (p = 0.004), but season 2 was not significantly different than season 3 (p = 0.232). Additionally, increases in PFa were noted from season 1 to season 2 (p = 0.010) and season 3 (p \u3c 0.001), but season 2 was not significantly different than season 3 (p = 0.052). Home runs per game rose from the 2009 (0.32) to 2010 season (1.35) and dropped during the 2011 season (1.07). A unique aspect of the study involves 2010 being the season in which ball-bat coefficient of restitution (BBCOR) bats were introduced to the NCAA competition

Simplifying External Load Data in NCAA Division-I Men\u27s Basketball Competitions: A Principal Component Analysis

The primary purpose was to simplify external load data obtained during Division-I (DI) basketball competitions via principal component analysis (PCA). A secondary purpose was to determine if the PCA results were sensitive to load demands of different positional groups (POS). Data comprised 229 observations obtained from 10 men\u27s basketball athletes participating in NCAA DI competitions. Each athlete donned an inertial measurement unit that was affixed to the same location on their shorts prior to competition. The PCA revealed two factors that possessed eigenvalues \u3e1.0 and explained 81.42% of the total variance. The first factor comprised total decelerations (totDEC, 0.94), average speed (avgSPD, 0.90), total accelerations (totACC, 0.85), total mechanical load (totMECH, 0.84), and total jump load (totJUMP, 0.78). Maximum speed (maxSPD, 0.94) was the lone contributor to the second factor. Based on the PCA, external load variables were included in a multinomial logistic regression that predicted POS (Overall model, p \u3c 0.0001; AUCcenters = 0.93, AUCguards = 0.88, AUCforwards = 0.80), but only maxSPD, totDEC, totJUMP, and totMECH were significant contributors to the model\u27s success (p \u3c 0.0001 for each). Even with the high significance, the model still had some issues differentiating between guards and forwards, as in-game demands often overlap between the two positions. Nevertheless, the PCA was effective at simplifying a large external load dataset collected on NCAA DI men\u27s basketball athletes. These data revealed that maxSPD, totDEC, totJUMP, and totMECH were the most sensitive to positional differences during competitions. To best characterize competition demands, such variables may be used to individualize training and recovery regimens most effectively

Effect of Post-Exercise Whole Body Vibration with Stretching on Mood State, Fatigue, and Soreness in Collegiate Swimmers

Static stretching (SS) during whole body vibration (WBV) has been suggested for exercise recovery. The purpose was to compare post-exercise self-ratings of fatigue (FAT), mood state (BAM), soreness (SOR), and perceived exertion (RPE) between SS and WBV+SS in swimmers (9 women, mean ± SD: 19.3 ± 1.3 year, 171 ± 5.7 cm, 67.6 ± 7.2 kg, 26.6 ± 4.1 %body fat (%BF); 10 men, mean ± SD: 19.7 ± 1.0 year, 183 ± 5.5 cm, 77.1 ± 4.2 kg, 13.1 ± 2.2 %BF). Athletes were divided by sex, event (sprint, distance), and assigned to SS or WBV+SS. Both conditions consisted of SS performed on the WBV platform with or without WBV (50 Hz, 6 mm). Sessions consisted of: pre and post measures of BAM, FAT, SOR; the condition; and RPE. Mixed factorial ANOVA were run. A significant condition by pre/post interaction was observed (p = 0.035). Post hoc analyses showed WBV+SS elicited lower post-exercise ratings of FAT (p = 0.002) and the BAM affective states, of tension (p = 0.031), and fatigue (p = 0.087). RPE did not differ between conditions. Of interest is the decrease in tension and fatigue noted by the BAM. Mood state can be indicative of how athletes adapt to training volume and intensity