Arm Isometric Force Production in NCAA Softball Players is Greater in the Dominant Arm Independent of Arm Angle

Arm Isometric Force Production in NCAA Softball Players is Greater in the Dominant Arm Independent of Arm Angle N. Henson1, M. Gersch1, K. Sunderland1 1Exercise and Performance Nutrition Laboratory, College of Science, Technology, and Health, Lindenwood University, St. Charles, MO, USA The Athletic Shoulder (ASH) test is used to examine strength symmetry between dominant and non-dominant shoulders. Our purpose was to examine shoulder isometric force production in college softball players at two arm angles. Seventeen college softball players performed bilateral isometric shoulder contractions on dual force plates while laying prone with arms straight and shoulders at 135˚ (“Y”) and 180˚ (“I”). There was no significant interaction between the arms in the “Y” and “I” positions. The dominant arm produced significantly greater force, independent of arm angle, compared to the non-dominant arm. Independent of arm tested, there was no significant difference in force production between the arm positions. College softball players produce more isometric force with their dominant arm independent of arm position. This force production could play a role in performance or injury risk

Female swimmers exhibit greater isometric force symmetry across the shoulder girdle than male swimmers

The Athletic Shoulder (ASH) test was developed to measure force across the shoulder girdle. This test can be used to assess symmetry and potential injury risk in upper-body sports. The purpose was to determine the differences in the supine-to-prone ratio of isometric shoulder force production between male and female swimmers. Forty-five Lindenwood swimmers (F=23, M=22) participated in this cross-sectional study. Athletes performed bilateral isometric shoulder contractions in both the supine and the prone laying position with arms straight and shoulders abducted 135˚ (“Y”). Female simmers had an higher average ratio (76.5%±13.5%) compared to males (68.1%±11.2%) independent of the arm tested. There were no significant difference between the arms independent of gender. This is the first study to ever report isometric ratios from the ASH test. Female swimmers produce force more symmetrically than male swimmers. Future research could examine the relationship between these ratios and performance or injury occurrence

Hamstrings to Quadriceps Peak Torque Ratios are Similar Between Positions in Male College Rugby Athletes

Decreased hamstrings strength relative to quadriceps strength (H:Q) is a potential risk factor for anterior cruciate ligament (ACL) injuries. The purpose was to determine the H:Q at varying angular velocities in male college rugby athletes. Thirty-eight male college rugby athletes volunteered for this study. Concentric peak torques were utilized to determine H:Q in the dominant leg with isokinetic dynamometry at 60 deg/s, 180 deg/s, 240 deg/s and 300 deg/s. There was no significant difference among position groups in peak torques, regardless of speed. H:Q was significantly lower at 60 deg/s compared to all other velocities. While H:Q does beneficially increase from 60 deg/s to 180 deg/s, the lack of further increases beyond 180 deg/s may indicate a potential injury risk. Previous reports have shown increased (\u3e60%) H:Q ratios at high angular velocities in male college athletes. These results provide potential for improved training to reduce ACL injury risk

Influence of Exercise on the Temporal Response of Serum Osteocalcin Following Nutrient Intake

Osteocalcin, also known as bone ã-carboxyglutamic acid, is an osteoblast-specific protein that has long be utilized in research as a marker of bone formation. Recently, osteocalcin has been recognized as a major regulator of glucose metabolism and insulin sensitivity. Osteocalcin deficient mice were shown to have decreased insulin secretion and insulin sensitivity and injections of recombinant osteocalcin reversed these dysfunctions. Furthermore, osteocalcin has been associated with obesity and insulin resistance in human adults. Osteocalcin has also been shown to transiently decrease following ingestion of a glucose load, while acute and long-term exercise has been shown to elevate osteocalcin in adults. Few studies investigating the temporal effects of glucose and/or exercise on osteocalcin levels have been published. Determining how OC responds to exercise and nutrients may help the understanding of how exercise influences glucose metabolism and lead to OC becoming a potential therapeutic target for type 2 diabetes. Therefore the purpose of this study is to examine the effects of a glucose load with or without a prior exercise bout on serum osteocalcin in overweight young men. Fifteen overweight young men were recruited. Subjects reported to the lab on three separate occasions. On two separate trials, conducted on in randomized order and separated by at least 4 days, serum carboxylated osteocalcin, undercarboxylated osteocalcin, glucose and insulin were measured during a standard 75-gram, 2-hour oral glucose tolerance test (OGTT). During one visit the subjects rested prior the glucose drink, while on the other visit aerobic interval exercise (EX) was performed just prior to ingestion of the glucose. There were no significant differences between the OGTT and EX trials in baseline serum cOC (32.24±21.32 vs 26.86±15.68 ng/mL, respectively), serum uOC (8.48±3.23 vs 9.03±3.68 ng/mL, respectively) or serum tOC (40.72±20.88 vs 35.90±17.98 ng/mL, respectively). There were also no significant differences between the OGTT and EX trials for cOC AUC (3466±2238 vs.3345±1873 ng min/mL, respectively; p=0.470), uOC AUC (932±385 vs. 989±422 ng min/mL, respectively; p=0.295), or tOC AUC (4399±2319 vs. 4334±2018 ng min/mL, respectively; p=0.727). Additionally, exercise did not alter the blood glucose or insulin concentrations compared to the resting trial. There were no significant associations between measurements of cOC, uOC or tOC and glucose or insulin at baseline or the post-glucose AUC. This study is the first to report the temporal response of serum OC within 2 hours of glucose ingestion. The results of the study reveal that a neither a bolus dose of glucose, nor exercise preceding the glucose drink altered serum cOC, uOC or tOC in sedentary, overweight young men. Additionally, there was no relationship between postprandial changes in serum cOC, uOC or tOC with glucose or insulin with or without a prior exercise bout. Therefore, OC does not appear to play a role in glycemic control in overweight but otherwise healthy young men

Physiological Measurements Pre/Post Ultra-Marathon Distance Race

Endurance running events like 100 miles distance races are becoming more popular. Humans are eager to explore their limits by challenging themselves to run 100 miles distance races. However, there are many research gaps still exist to fully understand the impact on the body that 100 miles endurance event has. The aim of this study was to measure and analyze the impact of the 100 miles endurance race among recreational runners. Ten male recreational runners (age 36.6 ± 14.1) were screened before and after completing 100 miles distance running event in Missouri. Test screening included VO2 max, RMR, BIA, Ultrasound of the vastus lateralis muscle, and Muscular strength performance (countermovement jumps (CMJ), bell squats). Overall, 100 miles distance running did not proof to have large impact on the body. The only significant changes were found in intracellular & extracellular body fluids, as well as, braking RDF (rate of force development), and force at peak braking force during CMJ testing

Naturally Bicarbonated Water Supplementation Does Not Improve Anaerobic Cycling Performance or Blood Gas Parameters in Active Men and Women

The completion of high-intensity exercise results in robust perturbations to physiologic homeostasis, challenging the body’s natural buffering systems to mitigate the accumulation of metabolic by-products. Supplementation with bicarbonate has previously been used to offset metabolic acidosis, leading to improvements in anaerobic exercise performance. Purpose: The purpose of this study was to investigate the presence of ergogenic properties in naturally occurring low-dose bicarbonated water and their effects on anaerobic cycling performance and blood gas kinetics in recreationally active men and women. Methods: Thirty-nine healthy, recreationally active men and women (28.1 ± 8.0 years, 169.8 ± 11.7 cm, 68.9 ± 10.8 kg, 20.1 ± 7.9% fat, V˙ role= presentation style= box-sizing: border-box; max-height: none; display: inline; line-height: normal; font-size: 13.2px; overflow-wrap: normal; text-wrap: nowrap; float: none; direction: ltr; max-width: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(34, 34, 34); font-family: Arial, Arial, Helvetica, sans-serif; position: relative; \u3eV˙V˙O2peak: 42.8 ± 7.6 mL/kg/min) completed two separate testing sessions consisting of 15 cycling sprints (10 s sprint, 20 s active rest) against 7.5% of their body mass. Using a randomized, double-blind, placebo-controlled, parallel group study design, study participants consumed a 10 mL/kg dose of either spring water (SW) or bicarbonated mineral water (BMW) (delivering ~3 g/day of bicarbonate) for 7 days. Venous blood was collected before, immediately after, and 5 and 10 min after the sprint protocol and was analyzed for lactate and a series of blood gas components. After the completion of 15 cycling sprints, averages of peak and mean power for bouts 1–5, 6–10, and 11–15, along with total work for the entire cycling protocol, were calculated. All performance and blood gas parameters were analyzed using a mixed-factorial ANOVA. Results: pH was found to be significantly higher in the BMW group immediately after (7.17 ± 0.09 vs. 7.20 ± 0.11; p = 0.05) and 10 min post exercise (7.21 ± 0.11 vs. 7.24 ± 0.09; p = 0.04). A similar pattern of change was observed 5 min post exercise wherein pH levels in the SW group were lower than those observed in the BMW group; however, this difference did not achieve statistical significance (p = 0.09). A statistical trend (p = 0.06) was observed wherein lactate in the BMW group tended to be lower than in the SW group 5 min post exercise. No significant main effect for time (p \u3e 0.05) or group × time interactions (p \u3e 0.05) for the total work, average values of peak power, or average values of mean power were observed, indicating performance was unchanged. Conclusion: One week of consuming water with increased bicarbonate (10 mL/kg; ~3 g/day bicarbonate) showed no effect on anaerobic cycling performance. BMW decreased blood lactate concentrations 5 min after exercise and increased blood pH immediately and 10 min after exercise

Metabolic impact of feeding prior to a 60-min bout of moderate-intensity exercise in females in a fasted state

BackgroundThe metabolic impact of pre-exercise feeding of protein or carbohydrate on fat oxidation and energy expenditure rates, especially, in females, is poorly understood.MethodsRecreationally active females (n = 15, 32 ± 10 years, 164.8 ± 5.6 cm, 63.5 ± 9.3 kg, 23.4 ± 3.2 kg/m2) completed four testing sessions in a randomized, double-blind, crossover fashion after fasting overnight. Participants ingested isovolumetric and isoenergetic solutions containing either 25 g of whey protein, casein protein, carbohydrate (CHO), or a non-caloric placebo (PLA). Participants then completed 60 min of treadmill exercise at 15% below ventilatory threshold 30 min after ingestion. Respiratory exchange ratio (RER) was evaluated throughout exercise and resting energy expenditure (REE) was assessed pre-exercise, and 0-, 60-, and 120-min post-exercise.ResultsA significant condition x time interaction was observed for RER (p = 0.008) during exercise, with CHO exhibiting higher RER values (vs. PLA) at four time points. A significant main effect for condition was observed for carbohydrate (p = 0.001) and fat (p = 0.02) oxidation rates during exercise, with fat oxidation rates being higher in PLA vs. CHO (p = 0.01). When total fat oxidized was calculated across the entire exercise bout, a significant main effect for condition was observed (p = 0.01), with PLA being greater than CHO (p = 0.04). A significant condition x time interaction (p = 0.02) was found for both absolute and normalized REE, with casein and whey protein having significantly higher values than CHO (p < 0.05) immediately post-exercise.ConclusionWhen compared to a fasted control (PLA), consuming CHO, but not protein, decreased total fat oxidation prior to a 60-min bout of moderate-intensity exercise in females

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Quantitative estimates of glacial refugia for chimpanzees (Pan troglodytes) since the Last Interglacial (120,000 BP).

Paleoclimate reconstructions have enhanced our understanding of how past climates have shaped present-day biodiversity. We hypothesize that the geographic extent of Pleistocene forest refugia and suitable habitat fluctuated significantly in time during the late Quaternary for chimpanzees (Pan troglodytes). Using bioclimatic variables representing monthly temperature and precipitation estimates, past human population density data, and an extensive database of georeferenced presence points, we built a model of changing habitat suitability for chimpanzees at fine spatio-temporal scales dating back to the Last Interglacial (120,000 BP). Our models cover a spatial resolution of 0.0467° (approximately 5.19 km2 grid cells) and a temporal resolution of between 1000 and 4000 years. Using our model, we mapped habitat stability over time using three approaches, comparing our modeled stability estimates to existing knowledge of Afrotropical refugia, as well as contemporary patterns of major keystone tropical food resources used by chimpanzees, figs (Moraceae), and palms (Arecacae). Results show habitat stability congruent with known glacial refugia across Africa, suggesting their extents may have been underestimated for chimpanzees, with potentially up to approximately 60,000 km2 of previously unrecognized glacial refugia. The refugia we highlight coincide with higher species richness for figs and palms. Our results provide spatio-temporally explicit insights into the role of refugia across the chimpanzee range, forming the empirical foundation for developing and testing hypotheses about behavioral, ecological, and genetic diversity with additional data. This methodology can be applied to other species and geographic areas when sufficient data are available