Strenuous Physical Training Research Articles

Patterns of Musculoskeletal Injuries Secondary to Strenuous Physical Training, Assessed on Magnetic Resonance Imaging

Patterns of Musculoskeletal Injuries Secondary to Strenuous Physical Training, Assessed on Magnetic Resonance Imaging

Venous thromboembolism among physically active young adult females

BackgroundYoung adult females are at risk of venous thromboembolism (VTE) due to various acquired and transient factors. In recent years, a growing number of females have engaged in strenuous physical activity, but its role as a risk factor for VTE is uncertain. ObjectivesTo determine the incidence of VTE in young adult females engaged in strenuous physical activity. MethodsA large national cohort of female individuals enlisted in the Israeli Defense Forces between 2012 and 2019 was analyzed. The study group consisted of participants undergoing strenuous physical training during their military service, while the control group maintained regular activity levels. We compared the incidence of VTE between the groups and adjusted for potential risk factors using a multivariate Cox analysis. ResultsThe cohort included 160,718 female individuals aged 18 to 21years, of whom 11,745 engaged in strenuous physical activity and 148,973 served as controls. During a mean follow-up of 1.7 years, VTE occurred in 5 individuals (0.04%) in the strenuous activity group and 47 individuals (0.03%) in the control group. The incidence per 10,000 person-years was 2.41 (95% CI, 0.78-5.62) for the strenuous activity group and 1.82 (95% CI, 1.34-2.42) for the controls. Strenuous activity did not increase the risk for VTE in univariate or multivariate regression, with a hazard ratio (HR) of 1.27 (95% CI, 0.49-4.22). Use of oral contraceptives was the only significant risk factor, demonstrating dose effect; HR 1.95 (95% CI, 1.06-3.57) for low dose and HR 3.62 (95% CI, 1.40-9.37) for medium estrogen dose contraceptives. ConclusionStrenuous physical activity did not increase the risk for VTE among a large cohort of young adult female individuals.

Injury epidemiology in Police Force recruits: a prospective cohort study of a rarely researched population

Introduction: Police Force recruits undergo strenuous physical, operational skills and combat training as a part of their academy qualification program, similarly to military recruits. However, a lack of published epidemiological injury data presents a major challenge to designing prevention programs appropriate for this population. Little to no data exists on injury epidemiology or risk factors. Our objectives were: 1) report the musculoskeletal injury epidemiology in Western Australian (WA) Police Force recruits, 2) determine the influence of age and sex on all injuries, and 3) examine the influence of running-related cardiorespiratory fitness on lower-limb and lumbosacral injury risk.

Investigation into the thermal comfort and physiological adaptability of outdoor physical training in college students

Over the last few decades, increase in global temperatures have led to a deterioration in the quality of open spaces, urban vitality, and public health. Strenuous physical training under hot conditions outdoors increases the potential for developing heat illnesses. It is therefore necessary to examine the relationships between human physiological indices, psychological responses, and outdoor thermal indices to predict and evaluate human thermal safety in hot environments. A 9-day experiment was conducted in September 2019, which tested the thermal comfort and cognitive ability of 1102 students. Their physiological parameters (Heart rate, Auditory canal temperature) were recorded before and after physical training. Results showed that there were significant differences in the thermal sensation vote before and after physical training. The classification of heat stress was modified based on the MTSV regression model and PET. The maximum acceptable PET was 23.0 °C before physical training and 21.7 °C after physical training. When PET ≥ 40.1 °C, a reduction in physical training intensity is recommended. When PET ≥ 45.7 °C, cessation of physical training should take place and sun exposure should be reduced to avoid health hazards. It is important to use the auditory canal temperature instead of the core temperature to calculate the physiological strain index (PSI). More than 15% of the subjects had a PSI ≥ 7.0 during the test. When the body is in a thermally neutral state (MTSV = −0.5– 0.5), PSI ≤ 2.0. When the MTSV ≥3.2, PSI ≥ 7.0, physical training intensity should be reduced, and warning information should be provided. According to the expected distribution of physical training time and rest time, it is recommended that the time of each physical training session should be within 30 min, with a resting period of more than 30 min in hot environments.

Recent Progress in Applicability of Exercise Immunology and Inflammation Research to Sports Nutrition.

This article focuses on how nutrition may help prevent and/or assist with recovery from the harmful effects of strenuous acute exercise and physical training (decreased immunity, organ injury, inflammation, oxidative stress, and fatigue), with a focus on nutritional supplements. First, the effects of ketogenic diets on metabolism and inflammation are considered. Second, the effects of various supplements on immune function are discussed, including antioxidant defense modulators (vitamin C, sulforaphane, taheebo), and inflammation reducers (colostrum and hyperimmunized milk). Third, how 3-hydroxy-3-methyl butyrate monohydrate (HMB) may offset muscle damage is reviewed. Fourth and finally, the relationship between exercise, nutrition and COVID-19 infection is briefly mentioned. While additional verification of the safety and efficacy of these supplements is still necessary, current evidence suggests that these supplements have potential applications for health promotion and disease prevention among athletes and more diverse populations.

Access to Care, Reporting Behaviors, and Quality of Athletic Training Service Interactions for Reserve Officers' Training Corps cadets

Purpose: Reserve Officers’ Training Corps (ROTC) programs prepare student-civilians to become leaders through strenuous physical and leadership training. Unlike their student-athlete counterparts who have direct access to athletic training services, ROTC cadets may or may not have a healthcare provider available. The purpose of this study was to examine the access to care and reporting behaviors of ROTC cadets with a secondary aim exploring the quality of healthcare service interactions relative to patient-centered care. Methods: An online survey assessed access to care using a self-report tool on the type of medical providers available to the ROTC cadets (n=132, age=20±3 y) dispersed between the Army, Navy, Air Force, and Marines, and their illness/injury history and reporting behaviors. The participants who sought care for an injury/illness also completed the Consultation and Relational Empathy tool to measure the level of patient-centered care by the healthcare provider with follow-up analysis using the Consultation Care Measure tool for all athletic training service interactions. Data were analyzed using descriptive statistics. Results: ROTC cadets reported access to 2±1 healthcare providers including a designated civilian physician (26.5%), athletic trainer (23.5%), and ROTC peer first responder (14.4%). However, 50.8% of respondents stated they were unsure what healthcare providers were available. In total, 22.7% of cadets reported being injured and 26.5% reported being sick/ill while participating in ROTC activities. Of those who stated they had sustained an injury during ROTC, 59.9% seldomly or never reported their injury. The ROTC cadets who sought healthcare expressed they were satisfied with their injury (35.96±10.60) and illness (35.48±13.10) treatment from a patient-centered viewpoint. Conclusions: The ROTC cadets reported a general unfamiliarity with the healthcare providers available to them. Despite the reporting behaviors, the cadets reported being satisfied with the care they received.

Strenuous Physical Training, Physical Fitness, Body Composition and Bacteroides to Prevotella Ratio in the Gut of Elderly Athletes

Regular physical activity seems to have a positive effect on the microbiota composition of the elderly, but little is known about the added possible benefits of strenuous endurance training. To gain insight into the physiology of the elderly and to identify biomarkers associated with endurance training, we combined different omics approaches. We aimed to investigate the gut microbiome, plasma composition, body composition, cardiorespiratory fitness, and muscle strength of lifetime elderly endurance athletes (LA) age 63.5 (95% CI 61.4, 65.7), height 177.2 (95% CI 174.4, 180.1) cm, weight 77.8 (95% CI 75.1, 80.5) kg, VO2max 42.4 (95% CI 39.8, 45.0) ml.kg–1.min–1 (n = 13) and healthy controls age 64.9 (95% CI 62.1, 67.7), height 174.9 (95% CI 171.2, 178.6) cm, weight 83.4 (95% CI 77.1, 89.7) kg, VO2max 28.9 (95% CI 23.9, 33.9), ml.kg–1.min–1 (n = 9). Microbiome analysis was performed on collected stool samples further subjected to 16S rRNA gene analysis. NMR-spectroscopic analysis was applied to determine and compare selected blood plasma metabolites mostly linked to energy metabolism. The machine learning (ML) analysis discriminated subjects from the LA and CTRL groups using the joint predictors Bacteroides 1.8E + 00 (95% CI 1.1, 2.5)%, 3.8E + 00 (95% CI 2.7, 4.8)% (p = 0.002); Prevotella 1.3 (95% CI 0.28, 2.4)%, 0.1 (95% CI 0.07, 0.3)% (p = 0.02); Intestinimonas 1.3E-02 (95% CI 9.3E-03, 1.7E-02)%, 5.9E-03 (95% CI 3.9E-03, 7.9E-03)% (p = 0.002), Subdoligranulum 7.9E-02 (95% CI 2.5E-02, 1.3E-02)%, 3.2E-02 (95% CI 1.8E-02, 4.6E-02)% (p = 0.02); and the ratio of Bacteroides to Prevotella 133 (95% CI -86.2, 352), 732 (95% CI 385, 1079.3) (p = 0.03), leading to an ROC curve with AUC of 0.94. Further, random forest ML analysis identified VO2max, BMI, and the Bacteroides to Prevotella ratio as appropriate, joint predictors for discriminating between subjects from the LA and CTRL groups. Although lifelong endurance training does not bring any significant benefit regarding overall gut microbiota diversity, strenuous athletic training is associated with higher cardiorespiratory fitness, lower body fat, and some favorable gut microbiota composition, all factors associated with slowing the rate of biological aging.

P515 A 12-week tailored physical training program including dietary advice in children with Inflammatory Bowel Disease: a randomized crossover trial

BackgroundInflammatory Bowel Disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract. Recently, physical activity has been suggested to improve the quality of life and course of disease in adult IBD patients. The aim of this study was to investigate physical functioning in paediatric IBD patients and to determine the effects of a tailored 12-week lifestyle intervention including a physical training program.MethodsFigure 1 shows our study design and measurements. The tailored 12-week lifestyle intervention consisted of 3 strenuous physical training sessions a week and dietary advice. Effects on exercise capacity, endurance, physical activity levels, disease activity, quality of life, and fatigue were measured in paediatric IBD patients. Mild disease activity was defined as a PCDAI between 10 - 27.5 or PUCAI between 10 - 34. ResultsSixteen paediatric IBD patients (median age 15 [9 - 17]) were included, 13 patients successfully completed the training program, 2 patients are still participating. At baseline, most patients had mild disease activity (n=9). Patients had reduced exercise capacity (76.8%±17.7% of predicted PeakVO2 , and reduced physical activity levels as shown by 80.3%±7.4% of measured time being spent in sedentary activity. PCDAI/PUCAI scores decreased significantly over the intervention period (13.8±11.7 vs. 3.65±4.5, P=0.002). Fecal calprotectin also decreased significantly (400 [18–3089] vs. 128 [20–2704], P=0.041). All patients but one had no changes in medical regimens before or during the lifestyle intervention that could have influenced disease activity. After the 12-week lifestyle intervention period, 9 out of 13 patients were in clinical remission. Maximum walked distance increased significantly (503±69 vs. 540±77 meters, P=0.001), although PeakVO2 and percentage of time spent in moderate-to-vigorous activity did not. Patients improved on overall quality of life measured by the Impact III questionnaire (+2.4 points, p=0.017). The Child Health Questionnaire showed a significant improvement on the child-reported physical functioning scale and on 5 parent-reported scales of quality of life. Child-reported fatigue measured by the PedsQol MFS did not improve significantly, parents-reported fatigue did. No changes were found on mentioned outcomes during the control period. After baseline measurements, the COVID-19 lock-down period started, possibly affecting normal daytime activities of the patients during the lifestyle intervention period.ConclusionA 12-week tailored physical training program including dietry advice is safe and beneficial for paediatric IBD patients and may contribute to better control of inflammation.

Splenic morphologic changes induced by a strenuous and exhaustive training program in Wistar rats.

Excessively intense physical training can compromise the functionality of the immune system and contribute to the appearance of symptoms associated with overtraining syndrome (OTS). The aim of this study was to analyze the splenic morphological changes in Wistar rats submitted to demanding training. The animals were randomly assigned to 2 groups; control group (CG) and exercise group (EG), animals in the EG group were sacrificed after 1 (EG1) and 3 weeks (EG3) of training. The animals were stimulated to run on the treadmill (-20 °; from 25 m/min, with a progressive increase of 1.25 m/minute at each session; 1 hour/day) 6 days/week. Body weight, food intake, appearance of hair, behavior and ability of animals to perform the imposed work were assessed during the protocol. The spleen was collected for histological analysis and immunohistochemical identification of CD4+ T lymphocytes and CD8+ T cells and NF-kB transcription factor. The protocol did not induce OTS, however, decreases were observed in areas of white pulp in EG3 in relation to the other groups. The training induced a decrease in splenic CD4+ T cells with an increase in CD8+ T cells. The training increased the expression of NF-κB P65 compared to sedentary animals. Even without manifestation of OTS, strenuous physical training, alter the histological and immunological structures of the spleen, suggesting in part a compromise in the functionality of the immune system.

Effects of almond, dried grape and dried cranberry consumption on endurance exercise performance, recovery and psychomotor speed: protocol of a randomised controlled trial

BackgroundFoods rich in nutrients, such as nitrate, nitrite, L-arginine and polyphenols, can promote the synthesis of nitric oxide (NO), which may induce ergogenic effects on endurance exercise performance. Thus, consuming...

Can strenuous exercise harm the heart? Insights from a study of cardiovascular neural regulation in amateur triathletes.

Regular exercise is recommended to improve the cardiovascular risk profile. However, there is growing evidence that extreme volumes and intensity of long-term exertion may increase the risk of acute cardiac events. The aim of this study is to investigate the after-effects of regular, strenuous physical training on the cardiovascular neural regulation in a group of amateur triathletes compared to age-matched sedentary controls. We enrolled 11 non-elite triathletes (4 women, age 24±4 years), who had refrained from exercise for 72 hours, and 11 age-matched healthy non-athletes (3 women, age 25±2 years). Comprehensive echocardiographic and cardiopulmonary exercise tests were performed at baseline. Electrocardiogram, non-invasive blood pressure, respiratory activity, and muscle sympathetic nerve activity (MSNA) were continuously recorded in a supine position (REST) and during an incremental 15° step-wise head-up tilt test up to 75° (TILT). Blood samples were collected for determination of stress mediators. Autoregressive spectral analysis provided the indices of the cardiac sympathetic (LFRR) and vagal (HFRR) activity, the vascular sympathetic control (LFSAP), and the cardiac sympatho-vagal modulation (LF/HF). Compared to controls, triathletes were characterized by greater LFRR, LF/HF ratio, LFSAP, MSNA, and lower HFRR at REST and during TILT, i.e. greater overall cardiovascular sympathetic modulation together with lower cardiac vagal activity. Cortisol and adrenocorticotropic hormone concentrations were also higher in triathletes. In conclusion, triathletes were characterized by signs of sustained cardiovascular sympathetic overactivity. This might represent a risk factor for future cardiovascular events, given the known association between chronic excessive sympathetic activity and increased cardiovascular risk.

Rhodiola rosea, a protective antioxidant for intense physical exercise: An in vitro study

In physiological conditions, the response to oxidative stress induced by strenuous physical training, is not always efficient. Furthermore, a weak muscle fiber antioxidant system can contribute to muscle wasting during ageing and pathological conditions. Natural antioxidant supplements could counteract the effects of oxidative stress. An in vitro model of exercise allowed us to mimic intense or moderate exercise by electrically stimulating cultured mouse myotubes with high- and/or low-frequency pulses; the resulting ROS production was then monitored. The herbal supplement Rhodiola rosea aqueous extract was characterized in terms of its polyphenol content and used to test for antioxidant activity against ROS, produced during muscle contraction. Our results showed that Rhodiola rosea extract reduced the oxidative stress produced by muscle contraction and brought values of ROS production back to physiological levels. We suggest that Rhodiola rosea root extract could exert a protective antioxidant role during intense physical exercise.

Prevalence of Iron Deficiency and Iron Deficiency Anemia in Strenuously Training Male Army Recruits

Objectives: The objectives of our study were to determine the effect of strenuous physical training on the prevalence of iron deficiency anemia (IDA), iron deficiency (ID) with normal hemoglobin (Hb), and anemia without ID. Methods: Our study was a prospective observational study. We followed 115 healthy male recruits in the Israel Defense Forces elite units during 15 months of training. Blood samples were collected at recruitment and at 6-, 9- and 15-month follow-ups. Results: Upon recruitment, anemia (Hb <14 g/dL), ID, and ID anemia (IDA) were diagnosed in 28, 31, and 9% of individuals, respectively. Sixty-three subjects (54%) were followed for 6 months; 9 of them (14%) developed new-onset IDA. Among them, the prevalence of anemia rose from 19 to 52%, and ID from 33 to 35%. At the 15-month follow-up, 29% had developed new-onset IDA and 65% showed evidence of ID. Conclusion: We report a high prevalence of anemia, ID, and IDA among young healthy males participating in prolonged strenuous training programs. These findings can be partly explained by the physiological changes associated with strenuous physical activity. Further investigations aiming to develop specific diagnostic guidelines for this unique population are warranted.

과훈련증후군과 면역반응의 임상적 분석

The present study was performed to analyze and review the physical and immune responses to over- training syndrome in humans. Overreaching refers to the initial phage of overtraining syndrome and has been known as a physical fatigue which is mainly from metab olic imbalance. It has been known that overtraining also results in a loss of adaptability which may lead to an attenuation of exercise performance, sleeping disorder, central fatigue, neurohormonal changes, difficulty recovery to physical stress, and immunological changes. Additionally, overtraining syndrome is characterized by persistent fatigue, poor performance in sport due to the prolonged and strenuous physical training. Also, pre- vious studies reported that endurance athletes experienced a hi gh incidence of URTI during intense training and the post training. And also, high-performance athletes reported that suppression of cell mediated and anti-body mediated immune function. NK cell number s were also reduced in the period of overtraining syndrome. Major components of prevention and treatment for the overtraining syn- drome are screening, education, and detraining. Furthermore, the combination of these prevention and treatment strategies will be much helpful. Therefore, the curre nt review will be helpful for athletes and individuals who are at the risk of overtraining syndrome.

Impact of Arm Immersion Cooling During Ranger Training on Exertional Heat Illness and Treatment Costs.

Ranger training includes strenuous physical activities and despite heat mitigations strategies, numerous cases of serious exertional heat illness (EHI) occur. We developed an Arm Immersion Cooling (AIC) system that is not logistically burdensome and may be easily employed in training environments. To examine the effect of AIC on EHI incidence, severity, and treatment costs during Ranger School. The training program was standardized for physical exertion and heat stress factors throughout the study period. AIC was employed summer months of 2010-2012 (n = 3,930 Soldiers) and Control (CON; n = 6,650 Soldiers) data were obtained for summer months of 2007-2009. Descriptive characteristics of all EHI casualties were obtained, including hospitalization status (treated and released [Treat], evacuated [Evac] or admitted [Admit] to the hospital), which served as proxy indicator of illness/injury severity. Medical cost savings were calculated from hospital records. Incidence rates were not different (CON 4.06 vs. AIC 4.00/1,000 person-days). Treat increased during AIC (18.43 vs. 4.84/1,000 person-days) accompanied by marked but non-significant decreases in Evac and Admit rates. AIC use was associated with a medical cost savings of $1,719 per casualty. AIC implementation during strenuous physical training in summer months can reduce EHI severity and associated medical treatment costs.

Outcomes following Complex Combat-Related Lumbosacral Dissociation Injuries

Introduction As war injury patterns have changed throughout Operations Iraqi and Enduring Freedom (OIF/OEF), a relative increase in the incidence of complex lumbosacral dissociation (LSD) injuries has been noted. LSD injuries are an anatomic separation of the spinal column from the pelvis, and represent a manifestation of severe, high energy trauma. We assessed the clinical outcomes of combat-related LSD injuries after operative treatment. Methods We performed a retrospective review of all patients surgically managed for complex LSD injuries since the beginning of current combat operations in the Middle East. Results A total of 20 patients met inclusion criteria and were treated as follows: posterior spinal fusion (12), sacroiliac screw fixation (7), and combined anterior–posterior fusion (1). The mean age was 28.2 years. The most common mechanism of injury was mounted improvised explosive device (IED, 50%). On average, 2.2 spinal regions were injured per patient. Neurologic dysfunction was present in four patients. Three patients underwent operative stabilization of their injuries before evacuation to the United States. Median time to surgery from injury was 12 days (range, 0–111 days). There was a 20% wound infection rate. Median follow-up was 45.5 months (range, 23.2–105.3 months), and one-third of all patients were medically retired because of their injuries. At most recent follow-up, 45% complained of chronic low back pain and 35% had persistent neurologic deficits; however, 30% were actively engaged in strenuous physical activities, including swimming, distance running, and training for special forces. Conclusion This is the largest series of operatively managed lumbosacral dissociation patients currently reported. Our series suggests that combat-related lumbosacral dissociation injuries frequently result in persistent, long-term neurologic dysfunction, disability, and chronic pain. Operative management carries a high postoperative risk of infection. However, two-thirds of patients were able to remain on active duty after their injuries, and two patients were able to complete marathon training.

Effect of N-acetylcysteine on Cycling Performance after Intensified Training

This investigation examined the ergogenic effect of short-term oral N-acetylcysteine (NAC) supplementation and the associated changes in redox balance and inflammation during intense training. A double-blind randomized placebo-controlled crossover design was used to assess 9 d of oral NAC supplementation (1200 mg·d) in 10 well-trained triathletes. For each supplement trial (NAC and placebo), baseline venous blood and urine samples were taken, and a presupplementation cycle ergometer race simulation was performed. After the loading period, further samples were collected preexercise, postexercise, and 2 and 24 h after the postsupplementation cycle ergometer race simulation. Changes in total antioxidant capacity, ferric reducing ability of plasma, reduced glutathione, oxidized glutathione, thiobarbituric acid-reactive substances, interleukin 6, xanthine oxidase, hypoxanthine, monocyte chemotactic protein 1, nuclear factor κB, and urinary 15-isoprostane F2t concentration were assessed. The experimental procedure was repeated with the remaining supplement after a 3-wk washout. Eight participants completed both supplementation trials. NAC improved sprint performance during the cycle ergometer race simulation (P < 0.001, ηp = 0.03). Supplementation with NAC also augmented postexercise plasma total antioxidant capacity (P = 0.005, ηp = 0.19), reduced exercise-induced oxidative damage (plasma thiobarbituric acid-reactive substances, P = 0.002, ηp = 0.22; urinary 15-isoprostane F2t concentration, P = 0.010, ηp = 0.431), attenuated inflammation (plasma interleukin 6, P = 0.002, ηp = 0.22; monocyte chemotactic protein 1, P = 0.012, ηp = 0.17), and increased postexercise nuclear factor κB activity (P < 0.001, ηp = 0.21). Oral NAC supplementation improved cycling performance via an improved redox balance and promoted adaptive processes in well-trained athletes undergoing strenuous physical training.

The Effect of 6-weeks Military Training on Blood Hematological Parameters in Untrained Recruits in a Military University

Abstract Freshmen officer cadets in a military university participating in 6 weeks of induction undergo strenuous physical training. Vigorous physical training has been shown to affect red and white blood cell and platelet parameters. Effects have been related to the mode of exercise involved. Since the induction training encompassed various modes of exercise, we studied the effect of physical training on basic anthropometric and hematologic parameters. Twenty-seven healthy freshmen officer cadets (13 male and 14 female) joined the study. A blood sample and basic anthropometric measures were collected before and 6 weeks into the induction program. An automated complete blood count was done. Both male and female subjects experienced significant reduction in weight, while only female candidates had lower waist circumference and body mass index (BMI). Red cell count and hemoglobin reduced and mean cell volume (MCV) and mean cell hemoglobin (MCH) increased in the males subjects. Females had lower red cell counts and hemoglobin which was not significantly different, however, their MCV and red cell distribution width (RDW) increased. We conclude that the subjects showed evidence of sports anemia, runners macrocytosis and platelet activation. Raised RDW seen among female participants might indicate poor tolerance in that group. Keywords: Physical activity, exercise, sports physiology, hematological parameters, platelet activation

Immunological Alterations Used to Predict Infections in Response to Strenuous Physical Training

The aim of this study was to screen leukocyte cell surface markers to identify possible predictors for infection related to physical training. Ten healthy soldiers (mean age, 19.1; mean body mass, 77.4 kg; mean VO2 peak, 4.54 L min(-1)/58.6 mL min(-1) kg(-1)) were included. Blood samples were collected and number of infections recorded before and after a 6-day training course. White blood cell distributions and expression of surface receptors changed during training. Before training, expression of CD3 on CD8+ lymphocytes and percent CD8+CD3 lymphocytes was lower, whereas CD4/CD8 ratio was higher among subjects who failed compared to those who completed the training. A subclinical infection before the start of the military training may alter the CD4/CD8 ratio. Prediction of future infections may be possible from pre-exercise immunological status, findings useful in military settings and exercise, where sudden infections may result in severe consequences.

Attenuation Of Exertional Muscle Damage With A Nutritional Supplement

Previous research suggests that glutamine (GLN) administration either during or following strenuous exercise modulates post-exercise inflammatory responses and may facilitate recovery. PURPOSE: This study studied the effects of GLN added to a beverage containing a carbohydrate (CHO) and an essential amino acid (EAA) mixture consumed during and after exercise on markers of EMD and performance in subjects following a strenuous physical training event. METHODS: Male subjects (n = 33; mean age of 24 years ± 1) completed this blinded-crossover study. Subjects were randomized to ingest either a placebo or treatment beverage during and after two identical events (modified physical fitness test), with the alternate beverage provided at the second event. Beverages were matched for CHO and EAA content (42 grams of CHO, 6 grams of EAA per liter) providing 192 calories. The GLN containing (4 grams) treatment beverage provided 208 calories per liter. RESULTS: No significant differences were noted (p ≤ 0.05) between groups with respect to muscle damage or inflammation, to include changes in creatine kinase, lactate dehydrogenase, white blood cell counts, C-reactive protein and select pro- and anti-inflammatory cytokines, as measured at baseline and after exercise. Creatine kinase, the primary variable of interest, increased after the training event in both groups indicating muscle damage had occurred. The treatment beverage did not significantly attenuate the response (p = 0.28). Plasma GLN levels remained relatively unchanged between placebo and treatment conditions, with both beverages blunting post-exercise induced decreases in GLN levels. Physical performance measures and pain scores were not significantly affected by the addition of GLN. CONCLUSIONS: Our findings suggest that the addition of GLN to a CHO/EAA beverage provided during and after exercise does not confer any significant benefit over a CHO/EAA beverage alone. The intervention failed to alter circulating GLN levels or measurably affect markers of EMD and the inflammatory response, and did not improve physical performance.