Intensive resistance exercise and circadian salivary testosterone concentrations among young male recreational lifters

Circadian rhythm in sportspersons and athletic performance: A mini review

Circadian rhythms in the physiological and behavioral processes of humans play a crucial role in the quality of living and also in the magnitude of success and failure in various endeavors including competitive sports. The rhythmic activities of the body and performance in sportspersons do have a massive impact on their every cutthroat competition. It is essential to schedule sports activities and training of players according to their circadian typology and time of peak performance for improved performance and achievement. In this review, the focus is on circadian rhythms and diurnal variations in peak athletic performance in sportspersons. Accuracy and temporal variability in peak performance in an individual could be attributed to various factors, namely chronotype, time of the day, body temperature, jetlag, hormones, and prior light exposure. Circadian rhythm of mood, alertness, T-core, and ultimately athletic performance is not only affected by sleep but also by circadian variations in hormones, such as cortisol, testosterone, and melatonin. There are, however, a few reports that are not consistent with the conclusions drawn in this review. Nevertheless, circadian rhythm and performance among sportspersons and athletes are important areas of research. This review might be useful to the managers and policymakers associated with competitive sports and athletic events.

Impact of military training stress on hormone response and recovery

Objectives

Military personnel are required to train and operate in challenging multi-stressor environments, which can affect hormonal levels, and subsequently compromise performance and recovery. The aims of this project were to 1) assess the impact of an eight-day military training exercise on salivary cortisol and testosterone, 2) track the recovery of these hormones during a period of reduced training.

Methods

This was a prospective study whereby 30 soldiers (n = 27 men, n = 3 women) undergoing the Australian Army combat engineer ‘Initial Employment Training’ course were recruited and tracked over a 16-day study period which included an eight-day military training exercise. Non-stimulated saliva samples were collected at waking, 30 min post waking, and bedtime on days 1, 5, 9, 13, 15; measures of subjective load were collected on the same days. Sleep was measured continuously via actigraphy, across four sequential study periods; 1) baseline (PRE: days 1–4), 2) field training with total sleep deprivation (EX-FIELD: days 5–8), 3) training at simulated base camp with sleep restriction (EX-BASE: days 9–12), and 4) a three-day recovery period (REC: days 13–15).

Results

Morning cortisol concentrations were lower following EX-FIELD (p<0.05) compared to the end of REC. Training in the field diminished testosterone concentrations (p<0.05), but levels recovered within four days. Bedtime testosterone/cortisol ratios decreased following EX-FIELD and did not return to pre-training levels.

Conclusions

The sensitivity of testosterone levels and the testosterone/cortisol ratio to the period of field training suggests they may be useful indicators of a soldier’s state of physiological strain, or capacity, however inter-individual differences in response to a multi-stressor environment need to be considered.

Differences in visio-spatial expertise between 1st division rugby players and non-athletes

The present study aimed to compare the visual expertise of non-athletes (n = 40; 19–35 years old; age: 22.13 ± 2.37 years) to amateur, non-professional South-African Rugby Union (SARU) first-division club rugby players (n = 40; 19–35 years old; age: 23.88 ± 4.36 years; training age mean: 9.0 ± 1.5 years). Research suggests that athletes have enhanced visio-spatial expertise in comparison to non-athletes. However, conflicting research suggests that this is not always the case as non-athletes possess similar visio-spatial expertise in certain visual skills. Participants underwent an optometric assessment after which the following 6 visio-spatial intelligence (VSI) components were measured; accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, visual memory and hand-eye coordination using the following tests; hart near far rock, saccadic eye movement, evasion, accumulator, flash memory and ball wall toss tests. Results indicated that first-division rugby players performed significantly better (p ≤ 0.05) in five of the six tests performed, except for visual memory (p = 0.893). While this study substantiates the notion that athletes, in this case first-division rugby players, performs significantly better in most VSI components, this is not the case for all, as with visual memory in this study. To more accurately distinguish between athletes and non-athletes, research should move away from tests that focus on basic visual function and develop sport specific testing methods that can be used by a variety of sports.

Effects of Training With Free Weights Versus Machines on Muscle Mass, Strength, Free Testosterone, and Free Cortisol Levels

Schwanbeck, SR, Cornish, SM, Barss, T, and Chilibeck, PD. Effects of training with free weights versus machines on muscle mass, strength, free testosterone, and free cortisol levels. J Strength Cond Res 34(7): 1851-1859, 2020-Free weights offer a more unstable training environment, which enhances muscle recruitment, whereas some machines have the advantage of using a "cam" pulley system that better matches strength curves. We compared the effect of training with free weights vs. machines on muscle mass, strength, free testosterone, and free cortisol concentrations. Forty-six subjects (26 women; 22 ± 3 years) were randomized to train using free weights or machines for 8 weeks (with each muscle group trained 2-3/weeks, 3-4 sets of 4-10 repetitions). Muscle thickness and strength were measured at 0 and 8 weeks. Salivary hormone concentrations were assessed before and at the end of workouts at the beginning, midway (4 weeks), and end (8 weeks) of the training intervention. Biceps and quadriceps muscle thickness increased (p < 0.01) with no difference between groups. There was a group × time interaction for machine bench press strength (p = 0.05) with the machine group increasing more than the free-weight group (13.9 vs. 8.6%). Free-weight bench press and squat, and Smith machine squat strength increased in both groups (11-19%; p < 0.01) with no difference between groups. Men in the free-weight group had a greater increase in free testosterone from before to after acute training sessions than men in the machine group and all women (p < 0.01); however, there was no differences between groups in free cortisol response to acute resistance exercise. Training sessions with free weights induced greater increases in free testosterone in men; however, training with free weights or machines resulted in similar increases in muscle mass and strength.

THE EFFECT OF EXERCISE ON INTERFERON GAMMA, BODY FAT AND BMI OF KIDNEY TRANSPLANT PATIENTS

ABSTRACT Introduction: Poor physical function and obesity are well documented in kidney transplant patients. Significant health benefits result from regular physical activity, many of which are important for kidney transplant patients. Objective: The aim of this study was to investigate the effects of 10-week combined exercises on Interferon Gamma (IFNγ), body fat percentage (BF%) and body mass index (BMI) in kidney transplant patients. Method: In a randomized controlled experimental design, 44 kidney transplant patients aged 20-50 years were randomly divided into two groups of exercise (n=23) and control (n=21). The exercise group participated in a cumulative training program for 10 weeks, three days a week, 60–90 minutes per day at 40-65% of predicted maximal heart rate reserve. A 5 ml venous blood sample and anthropometric parameters were taken from the subjects at baseline and after 10 weeks. Results: The exercise group showed an improvement in BF% (from 31.80±5.64 to 28.86 ± 5.82, p =0.001) and BMI (from 26.23 ± 1.81 to 25.45 ± 2.11, p = 0.001), but there was no significant change in the IFNγ level (from 0.06 ± 0.02 to 0.06 ± 0.02, p = 0.829). There was a significant difference between the control and exercise groups for BF% (p = 0.001) and BMI (p = 0.001). Conclusion: As a take-home message, it should be mentioned that combined exercise intervention is inexpensive and portable and can be performed at home or health centers for kidney transplant patients to reduce their weight and BF%. Evidence Level I; High quality randomized trial with or without statistically significant difference, but with narrow confidence intervals.

Realising the Potential of Urine and Saliva as Diagnostic Tools in Sport and Exercise Medicine

Accurate monitoring of homeostatic perturbations following various psychophysiological stressors is essential in sports and exercise medicine. Various biomarkers are routinely used as monitoring tools in both clinical and elite sport settings. Blood collection and muscle biopsies, both invasive in nature, are considered the gold standard for the analysis of these biomarkers in exercise science. Exploring non-invasive methods of collecting and analysing biomarkers that are capable of providing accurate information regarding exercise-induced physiological and psychological stress is of obvious practical importance. This review describes the potential benefits, and the limitations, of using saliva and urine to ascertain biomarkers capable of identifying important stressors that are routinely encountered before, during, or after intense or unaccustomed exercise, competition, over-training, and inappropriate recovery. In particular, we focus on urinary and saliva biomarkers that have previously been used to monitor muscle damage, inflammation, cardiovascular stress, oxidative stress, hydration status, and brain distress. Evidence is provided from a range of empirical studies suggesting that urine and saliva are both capable of identifying various stressors. Although additional research regarding the efficacy of using urine and/or saliva to indicate the severity of exercise-induced psychophysiological stress is required, it is likely that these non-invasive biomarkers will represent "the future" in sports and exercise medicine.

Impact of back squat training intensity on strength and flexibility of hamstring muscle group

STUDY DESIGN

True experimental design.

BACKGROUND

The back squat is an integral aspect of any resistance training program to improve athletic performance. It is also used for injury prevention of the lower limbs.

OBJECTIVE

The purpose of this study was to examine the effect of back squat training at different intensities on strength and flexibility of the hamstring muscle group (HMG).

METHODS

Twenty-two male recreational bodybuilders with at least two years of experience in resistance training were recruited to participate in a nine-week training program. They were randomly assigned to a heavy back squat group (90-95% of one repetition maximum) or a moderate-intensity back squat group (60-65% of one repetition maximum).

RESULTS

The heavy back squat group resulted in a significantly (p < 0.001) increased in one repetition maximum strength but a significant (p < 0.001) reduction in HMG flexibility when compared to their counterparts. The results of the study indicate that while a heavy back squat training program is effective in improving strength, it has an adverse effect on the flexibility of the HMG.

CONCLUSION

The implication of this study is that there is a tradeoff between strength and flexibility and trainers should select the appropriate training protocols for their athletes to maximize athletic performance.

Effects of endurance and high intensity training on ICAM-1 and VCAM-1 levels and arterial pressure in obese and normal weight adolescents

OBJECTIVES

Obesity prevalence has increased in Iranian adolescents in recent years. However, few studies have examined the impact of intervention programs on this health issue. The main objective of this study was to evaluate the effects of 8-week endurance training (ET) and high intensity interval training (HIIT) on intercellular adhesion molecule-1(ICAM-1) and vascular adhesion molecule-1(VCAM-1) levels among obese and normal-weight male adolescents.

METHODS

Thirty obese and 30 normal-weight subjects were assigned to the ET, HIIT, or control group for eight weeks. Before and after the intervention, ICAM-1, VCAM-1, body weight, BMI, VO2max, and blood pressures were measured. SPSS (Version 21) was used for data analysis, and the significance level was set at p < 0.05.

RESULTS

Mixed design ANOVAs indicated that the obese participants had significantly (p < 0.05) lower ICAM-1 levels in the ET (from 509 ± 61 ng/ml to 387 ± 43 ng/ml) and HIIT (from 517 ± 72 ng/ml to 374 ± 50 ng/ml), but their VCAM-1 level was significantly (p < 0.05) reduced only after the HIIT (from 1689 ± 119 ng/ml to 1282 ± 63 ng/ml). Similarly, normal weight participants significantly (p < 0.05) lowered their ICAM-1 levels in the ET (from 296 ± 18 ng/ml to 216 ± 14 ng/ml) and HIIT (from 289 ± 22 ng/ml to 202 ± 12 ng/ml), but their VCAM-1 level was significantly (p < 0.05) reduced only after the HIIT (from 895 ± 50 ng/ml to 673 ± 142 ng/ml). Systolic blood pressure and diastolic blood pressures of all the participants were significantly (p < 0.01) decreased at the conclusion of the ET and HIIT.

CONCLUSION

While both the ET and HIIT were useful in lowering the SBP and DBP of the participants, HIIT was more effective than ET in reducing ICAM-1 and VCAM-1 content in normal and obese adolescents.

Anabolic hormone profiles in elite military men

We recently characterized the awakening responses and daily profiles of the catabolic stress hormone cortisol in elite military men. Anabolic hormones follow a similar daily pattern and may counteract the catabolic effects of cortisol. This companion report is the first to characterize daily profiles of anabolic hormones dehydroepiandrosterone (DHEA) and testosterone in this population. Overall, the men in this study displayed anabolic hormone profiles comparable to that of healthy, athletic populations. Consistent with the cortisol findings in our prior report, summary parameters of magnitude (hormone output) within the first hour after awakening displayed superior stability versus summary parameters of pattern for both DHEA (r range: 0.77-0.82) and testosterone (r range: 0.62-0.69). Summary parameters of evening function were stable for the two hormones (both p<0.001), while the absolute decrease in testosterone across the day was a stable proxy of diurnal function (p<0.001). Removal of noncompliant subjects did not appreciably affect concentration estimates for either hormone at any time point, nor did it alter the repeatability of any summary parameter. The first of its kind, this report enables accurate estimations of anabolic balance and resultant effects upon health and human performance in this highly resilient yet chronically stressed population.

The prevalence of HTLV-1 and its Co-Infection with HCV, HBV and HIV in Hemophilic patients

Background and Objective:

Blood-borne infections, such as the HIV virus and hepatitis B and C, are major problems in patients receiving blood products. Here we examined the prevalence of HTLV-1, HCV, HBV, and HIV in hemophilic patients.

Methods:

A cross-sectional study on 108 hemophilic patients (101 males and 7 females) involved detection of HBV, HCV, HIV and HTLV-1 infections using immunoassays for HBsAg, hepatitis B core antibodies (anti-HBc), hepatitis C antibodies (anti-HCV), HIV antibodies (anti-HIV) and Anti-HTLV-1. Real-time PCR was used to measure HCV RNA, and HCV genotyping was performed by direct sequencing of the 5’ noncoding region.

Results:

Hemophilia A was reported in 93 (86%) patients with severe symptoms in 8 cases. The seroprevalence of anti-HCV and anti-HTLV-1 antibodies was 20% and 3% respectively. One patient with severe hemophilia had a HCV/HTLV-1 co-infection. HCV-RNA was detected in 82% of patients. In terms of genotyping prevalence was 56% HCV genotype 3a, 39% HCV genotype 1a, and 6% HCV genotype2. Anti HIV and HBsAg were not detected in any patient. HTLV1 prevalence was higher, HCV lower in South Khorasan than other regions in Iran or elsewhere.

Conclusion:

Management of transfusion of blood and blood products should account for the underlying prevalence of infectious agents.

Effects of polluted air on cardiovascular and hematological parameters after progressive maximal aerobic exercise

PURPOSE

Exercising or doing physical activity in polluted air could expose a person to the adverse health effects of air pollution. This study aimed to compare the cardiovascular and hematologic indices following an incremental exercise test (shuttle run) under clean versus polluted air conditions.

METHODS

Nineteen male athletes aged 21-27 years were assigned to either a trained athletes group (TA, n = 10) or a complete training cessation/detrained athletes group (DA, n = 9) at least 3-4 months after their competitive season. All participants performed the multi-stage shuttle run test on two separate days in either polluted air (37.4 carbon monoxide part per million) or clean air (2.5 carbon monoxide part per million) condition.

RESULTS

When compared to the clean air environment, progressive incremental exercise in polluted air condition significantly (p < .05) decreased maximal oxygen uptake (VO2max), red blood cell count, and hematocrit for both TA and DA groups. Meanwhile, the participants' mean corpuscular hemoglobin, mean red blood cell volume, white blood cells, and platelets in these two groups increased significantly (p < .05) when they were exercised in the polluted air ambiance. Maximal heart rate and heart rate recovery showed significant (p = .04) increases only in the DA group. However, hemoglobin concentration remained unchanged in both groups.

CONCLUSION

Acute exposure to high concentrations of pollutants during exercise resulted in decline in cardiovascular functions and hematological parameters in healthy athletes.