Search

Background: Ageing is accompanied by decreases in physical capacity and physiological regulatory mechanisms including altered hormonal regulation compared with age-matched sedentary people. The potential benefits of exercise in restoring such altered hormone production and secretion compared to age-matched physically inactive individuals who are ageing remains unclear. Objectives: The aim of this systematic review was to summarise the findings of exercise training in modulating levels of ostensibly anabolic and catabolic hormones in adults aged > 40 years. Methods: We searched the following electronic databases (to July 2021) without a period limit: Cochrane Library, PubMed, Science Direct, Scopus, SPORTDiscus and Web of Science. Additionally, a manual search for published studies in Google Scholar was conducted for analysis of the 'grey literature' (information produced outside of traditional commercial or academic publishing and distribution channels). The initial search used the terms 'ageing' OR 'advanced age' OR 'old people' OR 'older' OR elderly' AND 'anabolic hormones' OR 'catabolic hormones' OR 'steroid hormones' OR 'sex hormones' OR 'testosterone' OR 'cortisol' OR 'insulin' OR 'insulin-like growth factor-1' OR 'IGF-1' OR 'sex hormone-binding globulin' OR 'SHBG' OR 'growth hormone' OR 'hGH' OR 'dehydroepiandrosterone' OR 'DHEA' OR 'dehydroepiandrosterone sulfate (DHEA-S)' AND 'exercise training' OR 'endurance training' OR 'resistance training' OR ' strength training' OR 'weight-lifting' OR 'high-intensity interval training' OR 'high-intensity interval exercise' OR 'high-intensity intermittent training' OR 'high-intensity intermittent exercise' OR 'interval aerobic training' OR 'interval aerobic exercise' OR 'intermittent aerobic training' OR 'intermittent aerobic exercise' OR 'high-intensity training' OR 'high-intensity exercise' OR 'sprint interval training' OR 'sprint interval exercise' OR 'combined exercise training' OR 'anaerobic training'. Only eligible full texts in English or French were considered for analysis. Results: Our search identified 484 records, which led to 33 studies for inclusion in the analysis. Different exercise training programs were used with nine studies using endurance training programs, ten studies examining the effects of high-intensity interval training, and 14 studies investigating the effects of resistance training. Most training programs lasted ≥ 2 weeks. Studies, regardless of the design, duration or intensity of exercise training, reported increases in testosterone, sex hormone-binding globulin (SHBG), insulin-like growth factor-1 (IGF-1), human growth hormone (hGH) or dehydroepiandrosterone (DHEA) (effect size: 0.19 < d < 3.37, small to very large) in both older males and females. However, there was no consensus on the effects of exercise on changes in cortisol and insulin in older adults. Conclusion: In conclusion, findings from this systematic review suggest that exercise training increases basal levels of testosterone, IGF-1, SHBG, hGH and DHEA in both male and females over 40 years of age. The increases in blood levels of these hormones were independent of the mode, duration and intensity of the training programs. However, the effects of long-term exercise training on cortisol and insulin levels in elderly people are less clear. [ABSTRACT FROM AUTHOR]

The objective of present study is to investigate the effects of walk training with and without blood flow restriction (BFR and no-BFR) on lipid profiles, inflammatory and haematological factors in over-weighed men. Participants were divided into BFR (n = 9) or no-BFR (n = 9) groups. Both groups were exposed to 8-week walk training on a treadmill: 3 sessions/week at a speed of 50 m/min, 5 sets × 2 min/session. There were differences in pre- to post-levels of (TG) and fibrinogen in the BFR group (p ≤ 0.05) that were accompanied by changes in red blood cells (RBC), haemoglobin (HGB) and haematocrit (HCT) levels (p ≤ 0.05). RBC levels were increased in the BFR group (p ≤ 0.05). The groups differed in their mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC). These findings suggest the efficiency of BFR walk training in individuals exposed to chronic diseases associated with overweight, such as metabolic syndrome. [ABSTRACT FROM AUTHOR]

This study investigates the physiological/physical responses to a simulated mixed martial arts (MMA) competition over 24 hours. Twelve fighters performed a simulated MMA competition, consisting of three 5-minute MMA matches. Physiological/physical data were assessed before (Trest), directly after round 1 (Trd1), round 2 (Trd2) and round 3 (Trd3), and then 30 minutes (Trecovery30min) and 24 hours (Trecovery24h) post competition. Heart rate (HR), rating of perceived exertion (RPE), and blood lactate concentration ([La-]) were assessed at Trest, Trd1, Trd2, and Trd3. Biological data were collected at Trest, Trd3, Trecovery30min, and Trecovery24h. Physical tests were performed at Trest, Trecovery30min, and Trecovery24h. HR, RPE, and [La-] were high during competition. Leukocytes, hemoglobin, total protein, and glycemia were increased at Trd3 compared with all other time points (p ≤ 0.05). Cortisol was increased at Trd3 compared with Trest and Trecovery24h (p ≤ 0.05). Testosterone was higher at Trd3 and Trecovery30min than Trest (p < 0.001). Higher values of uric acid were noted during recovery periods (p < 0.001). Lactate dehydrogenase was lower at Trest compared with Trd3, Trecovery30min, and Trecovery24h (p ≤ 0.05). Countermovement jump was higher at Trest than Trecovery30min (p = 0.020). Consequently, MMA is a high-intensity intermittent combat sport that induces significant fatigue and muscle damage, both of which are still present at 24 hours post competition. [ABSTRACT FROM AUTHOR]

Background: Recently, several authors have proposed the use of a submaximal 'perceptually regulated exercise test' (PRET) to predict maximal oxygen uptake ( $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ ). The PRET involves asking the individual to self-regulate a series of short bouts of exercise corresponding to pre-set ratings of perceived exertion (RPE). The individual linear relationship between RPE and oxygen uptake (RPE: $$ \dot{V}{\text{O}}_{2} $$ ) is then extrapolated to the $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ , which corresponds to the theoretical maximal RPE (RPE). Studies suggest that prediction accuracy from this method may be better improved during a second PRET. Similarly, some authors have recommended an extrapolation to RPE rather than RPE. Objectives: The purpose of the meta-analysis was to examine the validity of the method of predicting $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ from the RPE: $$ \dot{V}{\text{O}}_{2} $$ during a PRET, and to determine the level of agreement and accuracy of predicting $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ from an initial PRET and retest using RPE and RPE. Data Sources: From a systematic search of the literature, 512 research articles were identified. Study Eligibility Criteria: The eligible manuscripts were those which used the relationship between the RPE and $$ \dot{V}{\text{O}}_{2} $$ , and used only the Borg's RPE scale. Participants and Interventions: Ten studies ( n = 274 individuals) were included. Study Appraisal and Synthesis Methods: For each study, actual and predicted $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ from four subgroup outcomes (RPE in the initial test, RPE in the retest, RPE in the initial test, RPE in the retest) were identified, and then compared. The magnitude of the difference regardless of subgroup outcomes was examined to determine if it is better to predict $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ from extrapolation to RPE or RPE. The magnitude of differences was examined for the best PRET (test vs retest). Results: The results revealed that $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ may be predicted from RPE: $$ \dot{V}{\text{O}}_{2} $$ during PRET in different populations and in various PRET modalities, regardless of the subgroup outcomes. To obtain greater accuracy of predictions, extrapolation to RPE during a retest may be recommended. Limitations: The included studies reported poor selection bias and data collection methods. Conclusions and Implications of Key Findings: The $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ may be predicted from RPE: $$ \dot{V}{\text{O}}_{2} $$ during PRET, especially when $$ \dot{V}{\text{O}}_{2\;\hbox{max} } $$ is extrapolated to RPE during a second PRET. [ABSTRACT FROM AUTHOR]

A response from the authors of the article "Submaximal, Perceptually Regulated Exercise Testing Predicts Maximal Oxygen Uptake: A Meta-Analysis Study" in the 2016 issue is presented.