Rapidly Progressing Secondary Organizing Pneumonia Due to Underlying Immunosuppression With Rituximab in SARS-CoV-2 Patients.

Secondary organizing pneumonia (SOP) as a sequela to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) usually has a prolonged benign course with a good response to corticosteroids. We present a case series of three patients who developed rapid progression to organizing pneumonia, after initial presentation with SARS-CoV-2. Imaging revealed rapid interval progression of bilateral subpleural ground glass opacities, and lung biopsy showed dense fibroblastic plugs within the alveoli. Two patients were steroid-responsive, and one patient succumbed to his illness despite maximal therapy. We postulate that B-cell depletion and immunosuppression may cause rapid progression to SOP, as all three patients were immunosuppressed and on chronic rituximab therapy.

The relationship between heart rate variability and glucose clearance in healthy men and women.

Heart rate variability (HRV) is a non-invasive indicator of the activity of the autonomic nervous system, which regulates many physiological functions including metabolism. The purpose of this study was to quantify the relationship between resting markers of HRV and oral glucose tolerance test (OGTT) response. Eighteen healthy individuals (10 males, 8 females, (23.8±2.9 years) underwent a 10-minute resting HRV recording. The final five minutes were evaluated via Kubios HRV Standard for: root mean square of successive differences (RMSSD), standard deviation of normal-to-normal sinus beats (SDNN), high frequency (HF), and low frequency (LF). A standard 2-hour OGTT was then administered. Glucose was measured via finger stick before, 30-minutes post, 1-hour post, and 2-hours post OGTT. Pearson correlations demonstrated that RMSSD, SDNN, HF and LF were strongly correlated to fasting blood glucose (FBG) for the group (p<0.05) but not for glucose area under the curve (AUC). When analyzed by sex, only males demonstrated significant correlations between AUC and RMSSD, SDNN, and LF (p<0.05). An independent samples t-test revealed no sex differences for FBG, AUC, RMSSD, SDNN, HF and LF. These findings provide new and interesting insights into the relationship of autonomic activity and glucose uptake, highlighting sex-based relationships.

Autonomic Rebound Following Maximal Exercise in Bodybuilders and Recreationally Active Participants.

The off-season for natural bodybuilders (BB) is characterized by increased training loads and fluctuations in caloric intake, which may lead to insufficient recovery. The autonomic nervous system (ANS) plays a pivotal role in recovery. The purpose of this study was to evaluate resting ANS activity and recovery following a maximal exercise bout in off-season BB and compare them to those of recreationally active individuals. Fifteen males participated; 7 recreationally active (RA) (24.6 ± 2.1 years, 81.1 ± 10.8 kg) and 8 BB (21.8 ± 2.9 years, 89.3 ± 13.0 kg). Each performed a graded exercise test. Heart rate variability (HRV) was measured at rest and during a 45 min recovery period. HRV was analyzed as: root mean square of successive differences (lnRMSSD), standard deviation of normal-to-normal sinus beats (lnSDNN), high frequency (lnHF), low frequency (lnLF), and the ratio of low frequency to high frequency (lnLF/lnHF). A one-way ANOVA showed no differences for any resting marker of HRV, HR, and HR recovery. A significant depression in all markers of HRV was observed in the BB group at the 15 min point, and no recovery was observed before 45 min when compared to RA. The results of this study demonstrated depressed HRV recovery following the graded exercise test in BB when compared to the RA group.

Carbohydrate Rinse Fails to Enhance Cycling Performance or Alter Metabolic and Autonomic Recovery in Recreational Cyclists.

The purpose of the study was to examine the effects of carbohydrate (CHO) mouth rinsing on autonomic and metabolic recovery as well as cycling performance. Ten male recreational cyclists (age = 30 ± 6 years, VO2peak = 54.5 ± 8.1 mL·kg-1·min-1) completed a randomized, double-blind, placebo-controlled, crossover designed study. A CHO or a placebo (PLA) rinse was administered every 12.5% of a work to completion trial (75%Wmax). Heart rate variability (lnRMSSD), the respiratory exchange ratio, and plasma epinephrine, norepinephrine, insulin, glucose, free fatty acids (FFA), and lactate were measured pre- and post-exercise. The CHO rinse did not improve time to completion of the test trial (CHO: 4108 ± 307 s, PLA: 4176 ± 374 s, p = 0.545). Further, the CHO rinse did not impact autonomic recovery, as measured by lnRMSSD (p = 0.787) and epinephrine (p = 0.132). Metabolic biomarkers were also unaffected by the CHO rinse, with no differences observed in responses of FFA (p = 0.064), lactate (p = 0.302), glucose (p = 0.113) or insulin (p = 0.408). Therefore, the CHO mouth rinse does not reduce the acute sympathetic response following strenuous exercise and does not result in improvements in cycling time to completion.

Steps expressed relative to body fat mass predicts body composition and cardiometabolic risk in adults eating ad libitum.

BACKGROUND: Excess body fatness is a consequence of a chronic energy surplus (energy intake is greater than energy expenditure). Given the serious health consequences of excess body fatness, factors that influence energy balance and body composition are increasingly important to understand. METHODS: A total of 34 adults between the ages of 19-40 years made a laboratory visit in which height, weight, body composition, and cardiometabolic risk (CMR) factors were quantified. Participants wore accelerometers for 21-28 days, then returned to the laboratory for a second body composition assessment. Changes in weight and body composition were used to quantify energy balance, and data derived from accelerometers provided markers of physical activity (PA) and sedentariness. RESULTS: Of the markers of PA that we measured, daily step counts expressed relative to fat mass was most strongly and consistently associated with body fatness and CMR status. CONCLUSIONS: Step counts expressed relative to fat mass were strongly associated with body composition and CMR in adults eating ad libitum. Longitudinal interventional studies are necessary to determine the efficacy of step count prescriptions expressed relative to existing and target body fatness and CMR levels for improving weight management and metabolic outcomes.

Should Body Size Categories Be More Common in Endurance Running Events?

Thousands of endurance running events are held each year in the United States, and most of them use age and sex categories to account for documented effects of those factors on running performance. However, most running events do not provide categories of body mass, despite abundant evidence that it, too, dramatically influences endurance running performance. The purposes of this article are to (1) discuss how body mass affects endurance running performance, (2) explain several mechanisms through which body mass influences endurance running performance, and (3) suggest possible ways in which body mass might be categorized in endurance running events.

Associations between measures of health-related physical fitness and cardiometabolic risk factors in college students.

OBJECTIVE: To determine the influence of health-related fitness on cardiometabolic risk factors in college students. PARTICIPANTS: 75 traditional students (33 men and 42 women, 21.8±1.8 years old) at a university in southeastern U.S. METHODS: Height, weight, waist circumference, body composition, blood pressure, lipids, glucose, insulin, c-reactive protein, and glucose tolerance were measured. Indices of insulin sensitivity were calculated. Aerobic and muscular fitness were measured. Regression and correlation analyses, and comparisons of cardiometabolic markers in low- vs high-fit participants were performed. RESULTS: Men and women with low muscular fitness exhibited higher fasting insulin, and poorer insulin sensitivity index scores than those with high muscular fitness. In addition, women with high body fat percentage exhibited higher fasting and 2-hour insulin levels and lower insulin sensitivity index scores than those with low body fat percentages. CONCLUSIONS: College students possessing low levels of health-related physical fitness exhibited less favorable cardiometabolic risk profiles.

Exercise for the management of type 2 diabetes mellitus: factors to consider with current guidelines.

It has long been established that exercise is powerful medicine for those with type 2 diabetes mellitus (T2DM), such that it should represent a priority in the treatment and management of that condition. In spite of this, exercise adherence among those with T2DM is low, with lack of time and fear of doing harm commonly cited as reasons for not being more active. Published guidelines for aerobic exercise in those with T2DM recommend only moderate intensity, due to the elevated risk of untoward outcomes with more vigorous exercise in persons with chronic disease. However, considerable research evidence has appeared in the literature since the publication of those guidelines in 2010 addressing the safety and efficacy of more vigorous forms of exercise (i.e., interval training) in those with T2DM. Many such studies have reported improvements in glucose control as great as or greater than those associated with moderate intensity exercise, with significantly reduced time requirements, and mechanisms of improved glucose control via interval training may be unique to this mode of exercise. Resistance training, too, appears to confer significant improvements in glucose control in those with T2DM through unique mechanisms. These recent findings may be of interest to physicians and exercise practitioners, as they may provide for greater adherence to more optimal exercise prescriptions that are better suited to each patient's time availability and motivational level.

A tutorial on oxidative stress and redox signaling with application to exercise and sedentariness.

Oxidative stress has been shown to play a role in the etiology of several chronic diseases, including cardiovascular disease, diabetes mellitus, and cancer. Free radicals and, most prominently, the superoxide radical, result from oxidative metabolism and several enzyme-catalyzed reactions, and endogenous cellular antioxidants dismutate many reactive oxygen species (ROS). Under certain conditions, ROS production can outpace dismutation (e.g., long-term sedentariness and positive energy balance) and the result is oxidative stress, with proteins, lipids, and DNA the most common targets of radicals. However, the molecules that contribute to oxidative stress also appear to participate in vital cell signaling activity that supports health and stimulates favorable adaptations to exercise training, such that inhibiting ROS formation prevents common adaptations to training. Furthermore, researchers have recently suggested that some proteins are not as readily formed when the redox state of the cell is insufficiently oxidative. Exercise training appears to optimize the redox environment by dramatically enhancing the capacity of the cell to neutralize ROS while regularly creating oxidative environments in which membrane and secretory proteins can be synthesized. The role that exercise plays in enhancing management of ROS likely explains many of the associated health benefits.

Comparison of an in-helmet temperature monitor system to rectal temperature during exercise.

Body temperature monitoring is crucial in helping to decrease the amount and severity of heat illnesses; however, a practical method of monitoring temperature is lacking. In response to the lack of a practical method of monitoring the temperature of athletes, Hothead Technologies developed a device (HOT), which continuously monitors an athlete's fluctuations in body temperature. HOT measures forehead temperature inside helmets. The purpose of this study was to compare HOT against rectal temperature (Trec). Male volunteers (n = 29, age = 23.5 ± 4.5 years, weight = 83.8 ± 10.4 kg, height = 180.1 ± 5.8 cm, body fat = 12.3 ± 4.5%) exercised on a treadmill at an intensity of 60-75% heart rate reserve (HRR) (wet bulb globe temperature [WBGT] = 28.7° C) until Trec reached 38.7° C. The correlation between Trec and HOT was 0.801 (R = 0.64, standard error of the estimate (SEE) = 0.25, p = 0.00). One reason for this relatively high correlation is the microclimate that HOT is monitoring. HOT is not affected by the external climate greatly because of its location in the helmet. Therefore, factors such as evaporation do not alter HOT temperature to a great degree. HOT was compared with Trec in a controlled setting, and the exercise used in this study was moderate aerobic exercise, very unlike that used in football. In a controlled laboratory setting, the relationship between HOT and Trec showed favorable correlations. However, in applied settings, helmets are repeatedly removed and replaced forcing HOT to equilibrate to forehead temperature every time the helmet is replaced. Therefore, future studies are needed to mimic how HOT will be used in field situations.

Uterine pleomorphic rhabdomyosarcoma: a case report and review of literature.

Primary pleomorphic rhabdomyosarcoma of the uterus is a very rare neoplasm. We describe a 65-year old female with this diagnosis, who underwent an abdominal hysterectomy with bilateral salpingo-oophorectomy and lymph node dissection. Also included is a discussion on the different types of rhabdomyosarcoma with reviews of their histological features, epidemiology and common sites of origin.

Sit-and-reach flexibility and running economy of men and women collegiate distance runners.

Flexibility has been controversially suggested as one of the biomechanical factors contributing to the variability observed in running economy among distance runners. The purpose of this investigation was to determine the magnitude of the relationship between sit-and-reach flexibility and running economy in men and women. Eight collegiate distance runners (4 men and 4 women) served as subjects for this correlational study (age = 19.9 +/- 1.25 years; VO2max = 63.2 +/- 3.4 mlxkgxmin). Each subject's flexibility was measured using the standard sit-and-reach test, and running economy was recorded during an incremental maximal treadmill test at both absolute (men = 241.2 mxmin; women = 198.32 mxmin) and relative (10-km pace) velocities. Statistical analyses indicated a significant relationship between sit-and-reach scores and running economy at an absolute velocity (r = 0.826, p

The effect of resistive exercise rest interval on hormonal response, strength, and hypertrophy with training.

The purpose of this study was to compare the effects of different between-set rest periods (1 and 2.5 minutes) on changes in hormone response, strength, arm cross-sectional area (CSA), thigh muscular cross-sectional area (MCSA), and body composition during a 10-week training period. Twelve untrained males (24.8 +/- 5.9 years) engaged in resistance training using either 1 minute (short rest [SR], n = 6) or 2.5 minutes (long rest [LR], n = 6) of rest between sets, with a load that elicited failure on the third set of each exercise. Body composition, thigh MCSA, arm CSA, and five-repetition maximum (RM) squat and bench press were assessed before and after training. Blood samples were collected after exercise in weeks 1, 5, and 10. In week 1, postexercise plasma testosterone levels were greater in SR (0.41 +/- 0.17 mmolxL) than in LR (0.24 +/- 0.06 mmol x L, p < 0.05), and postexercise cortisol levels were greater in SR (963 +/- 313 mmol x L) than in LR (629 +/- 127 mmol x L, p < 0.05). Week 1 postexercise GH levels were not different (p = 0.28). The differences between hormone levels in weeks 5 and 10 were not significant. Arm CSA increased more with LR (12.3 +/- 7.2%) than with SR (5.1 +/- 2.9%, p < 0.05). There were no differences in strength increases. These results show that in healthy, recently untrained males, strength training with 1 minute of rest between sets elicits a greater hormonal response than 2.5-minute rest intervals in the first week of training, but these differences diminish by week 5 and disappear by week 10 of training. Furthermore, the hormonal response is highly variable and may not necessarily be predictive of strength and lean tissue gains in a 10-week training program.

Heat production and storage are positively correlated with measures of body size/composition and heart rate drift during vigorous running.

The purposes of this study were to determine the relationships between: (a) measures of body size/composition and heat production/storage, and (b) heat production/storage and heart rate (HR) drift during running at 95% of the velocity that elicited lactate threshold, which was determined for 20 healthy recreational male runners. Subsequently, changes in skin and tympanic temperatures associated with a vigorous 20-min run, HR, and VO2 data were recorded. It was found that heat production was significantly correlated with body mass (r = .687), lean mass (r = .749), and body surface area (BSA, r = .699). Heat storage was significantly correlated with body mass (r = .519), fat mass (r = .464), and BSA (r = .498). The percentage of produced heat stored was significantly correlated with body mass (r = .427), fat mass (r = .455), and BSA (r = .414). Regression analysis showed that the sum of body mass, percentage of body fat, BSA, lean mass, and fat mass accounted for 30% of the variability in heat storage. It was also found that HR drift was significantly correlated with heat storage (r = .383), percentage of produced heat stored (r = .433), and core temperature change (r = .450). It was concluded that heavier runners experienced greater heat production, heat storage, and core temperature increases than lighter runners during vigorous running.

Relationship between measures of body size and composition and velocity of lactate threshold.

The purpose of this investigation was to explore the relationship between velocity of lactate threshold (vLT) and various measures of body mass and composition: mass, lean mass, fat mass, percent body fat (% fat), and body surface area (BSA). We hypothesized that mass would be inversely related to vLT, and that differences in measures of body mass and composition would account for a significant amount of variability in vLT. A total of 21 healthy male runners served as subjects. Body composition was assessed by hydrostatic weighing. A significant negative relationship (r = -0.759, p < or = 0.01) was between body mass and vLT. The coefficient of determination between vLT and body mass indicated that nearly 58% of the variability in vLT was explained by body mass in these subjects. Significant relationships were also between vLT and BSA (r = -0.72, p < or = 0.01), fat mass (r = -0.70, p < or = 0.01), % fat (r = -0.59, p < or = 0.01), and lean mass (r = -0.41, p < or = 0.05). Linear regression yielded the following model: y = 369.48 - 1.7343 (X), where y = predicted vLT (m.min(-1)) and X = body mass (kilograms) (SEE = 15.45). Velocity of lactate threshold was significantly inversely related with body mass in a group of male runners. The calculated coefficient of determination suggests that nearly 58% of the variability in vLT was explained by body mass. The present data suggest consideration of categorizing participants in 'road runs' by body mass to equate competition, as is done in other sports (e.g., weightlifting).

Scaling oxygen uptake to body size and several practical applications.

Oxygen uptake (VO(2)) has typically been expressed in milliliters per kilogram per minute to equate people of different body masses. However, research suggests that VO(2) increases in proportion to body mass raised to a power between 0.6 and 0.75, rather than in proportion to body mass raised to a power of 1. The potential for several errors arises when using a body mass exponent of 1 (ml x kg(-1).min(-1)), and these include the following: (a) penalizing larger subjects and inflating the scores of lighter subjects when comparing maximal aerobic capacity scores, (b) inaccurately estimating aerobic capacity via submaximal tests, causing misinterpretations of those scores, and (c) reducing accuracy in the assessment of movement economy and the energy cost of physical activity. Expressions of VO(2) scaled to body mass to a power less than 1 tend to minimize the bias and errors associated with linear-relative expressions (ml x kg(-1) x min(-1)). The purpose of this article is to briefly review recent literature related to the scaling of VO(2) to body size and to consider some of the practical applications suggested by the review. These implications appear to be important for fitness professionals, strength and conditioning coaches, and exercise scientists.