Rating of Perceived Exertion Associated With Acute Symptoms in Athletes With Recent SARS-CoV-2 Infection: Athletes With Acute Respiratory InfEction (AWARE) VI Study.

CONTEXT: SARS-CoV-2 infection can affect the exercise response in athletes. Factors associated with the exercise response have not been reported. OBJECTIVE: To (1) describe heart rate (HR), systolic blood pressure (SBP), and rating of perceived exertion (RPE) responses to exercise in athletes with a recent SARS-CoV-2 infection and (2) identify factors affecting exercise responses. DESIGN: Cross-sectional, experimental study. PATIENTS OR OTHER PARTICIPANTS: Male and female athletes (age = 24.2 ± 6.3 years) with a recent (<28 days) SARS-CoV-2 infection (n = 72). SETTING: A COVID-19 Recovery Clinic for athletes. MAIN OUTCOME MEASURE(S): Heart rate, SBP, and RPE were measured during submaximal exercise (modified Bruce protocol) at 10 to 28 days after SARS-CoV-2 symptom onset. Selected factors (demographics, sport, comorbidities, preinfection training variables, and symptoms during the acute phase of the infection) affecting the exercise response were analyzed using random coefficient (linear mixed) models. RESULTS: Heart rate, SBP, and RPE increased progressively from rest to stage 5 of the exercise test (P = .0001). At stage 5 (10.1 metabolic equivalents), a higher HR and a higher SBP during exercise were associated with younger age (P = .0007) and increased body mass index (BMI; P = .009), respectively. Higher RPE during exercise was significantly associated with a greater number of whole-body (P = .006) and total number (P = .004) of symptoms during the acute phase of infection. CONCLUSIONS: A greater number of symptoms during the acute infection was associated with a higher RPE during exercise in athletes at 10 to 28 days after SARS-CoV-2 infection. We recommend measuring RPE during the first exercise challenge after infection, as this may indicate disease severity and be valuable for tracking progress, recovery, and return to sport.

Factors associated with patellofemoral pain in recreational road cyclists: A cross-sectional study in 59953 cyclists - SAFER XXXIII.

OBJECTIVE: Patellofemoral pain (PFP) is a common cycling-related injury, and independent factors need to be identified to enable effective injury prevention strategies. We aim to determine factors associated with PFP in cyclists entering mass community-based events. DESIGN: Cross-sectional study. SETTING: 2016-2020 Cape Town Cycle Tour. PARTICIPANTS: Consenting race entrants. MAIN OUTCOME MEASURES: 62758 consenting race entrants completed a pre-race medical questionnaire, and 323 reported PFP. Selected factors associated with PFP (demographics, cycling experience and training, chronic disease history) were explored using multivariate analyses. RESULTS: Prevalence ratio (PR) of PFP was similar for sex and age groups. Independent factors associated with PFP (adjusted for sex and age) were history of chronic disease [Composite Chronic Disease Score (0-10)(PR = 2.0, p < 0.0001) and any allergies (PR = 2.0, p < 0.0001)]. CONCLUSION: A history of chronic diseases and allergies is associated with PFP in cyclists. Practical clinical recommendations are: 1) that prevention programs for PFP be considered when cycling is prescribed as a physical activity intervention for patients with chronic disease, and 2) that older cyclists presenting with PFP be assessed for the presence of risk factors or existing chronic disease.

Clinical characteristics of gradual onset injuries in recreational road cyclists - SAFER XXVII study over 5 years in 62758 race entrants.

OBJECTIVE: Gradual onset injuries (GOIs) in recreational cyclists are common but not well described. The aim of this study is to describe the clinical characteristics of GOIs (main anatomical regions, specific anatomical sites, specific GOIs, tissue type, severity of GOIs, and treatment modalities) of GOIs among entrants participating in a community-based mass participation-cycling event over 5 years. METHODS: During the 2016-2020 Cape Town Cycle Tour, 62,758 consenting race entrants completed an online pre-race medical screening questionnaire. 1879 reported GOIs in the previous 12 months. In this descriptive epidemiological study, we report frequency (% entrants) of GOIs by anatomical region/sites, specific GOI, tissue type, GOI severity, and treatment modalities used. RESULTS: The main anatomical regions affected by GOIs were lower limb (47.4%), upper limb (20.1%), hip/groin/pelvis (10.0%), and lower back (7.8%). Specifically, GOI were common in the knee (32.1%), shoulder (10.6%), lower back (7.8%) and the hip/buttock muscles (5.2%). The most common specific GOI was anterior knee pain (17.2%). 57.0% of GOIs were in soft tissue. Almost half (43.9%) of cyclists with a GOI reported symptom duration >12 months, and 40.3% of GOIs were severe enough to reduce/prevent cycling. Main treatment modalities used for GOIs were rest (45.9%), physiotherapy (43.0%), stretches (33.2%), and strength exercises (33.1%). CONCLUSION: In recreational cyclists, >50% of GOIs affect the knees, shoulders, hip/buttock muscles and lower back, and 40% are severe enough to reduce/prevent cycling. Almost 45% of cyclists with GOIs in the lower back; or hip/groin/pelvis; or lower limbs; or upper limb reported a symptom duration of >12 months. Risk factors associated with GOIs need to be determined and preventative programs for GOIs need to be designed, implemented, and evaluated.

Symptom Number and Reduced Preinfection Training Predict Prolonged Return to Training after SARS-CoV-2 in Athletes: AWARE IV.

PURPOSE: This study aimed to determine factors predictive of prolonged return to training (RTT) in athletes with recent SARS-CoV-2 infection. METHODS: This is a cross-sectional descriptive study. Athletes not vaccinated against COVID-19 ( n = 207) with confirmed SARS-CoV-2 infection (predominantly ancestral virus and beta-variant) completed an online survey detailing the following factors: demographics (age and sex), level of sport participation, type of sport, comorbidity history and preinfection training (training hours 7 d preinfection), SARS-CoV-2 symptoms (26 in 3 categories; "nose and throat," "chest and neck," and "whole body"), and days to RTT. Main outcomes were hazard ratios (HR, 95% confidence interval) for athletes with versus without a factor, explored in univariate and multiple models. HR < 1 was predictive of prolonged RTT (reduced % chance of RTT after symptom onset). Significance was P < 0.05. RESULTS: Age, level of sport participation, type of sport, and history of comorbidities were not predictors of prolonged RTT. Significant predictors of prolonged RTT (univariate model) were as follows (HR, 95% confidence interval): female (0.6, 0.4-0.9; P = 0.01), reduced training in the 7 d preinfection (1.03, 1.01-1.06; P = 0.003), presence of symptoms by anatomical region (any "chest and neck" [0.6, 0.4-0.8; P = 0.004] and any "whole body" [0.6, 0.4-0.9; P = 0.025]), and several specific symptoms. Multiple models show that the greater number of symptoms in each anatomical region (adjusted for training hours in the 7 d preinfection) was associated with prolonged RTT ( P < 0.05). CONCLUSIONS: Reduced preinfection training hours and the number of acute infection symptoms may predict prolonged RTT in athletes with recent SARS-CoV-2. These data can assist physicians as well as athletes/coaches in planning and guiding RTT. Future studies can explore whether these variables can be used to predict time to return to full performance and classify severity of acute respiratory infection in athletes.

The cardiovascular response to exercise in athletes recovering from SARS-CoV-2 infection: A prospective cohort study with repeated measures over 16 weeks - AWARE IX.

Higher exercise heart rate (HR) and prolonged return-to-sport in athletes with SARS-CoV-2 infection are described, but the cardiovascular response to exercise during recovery is not understood. This prospective, cohort, experimental study with repeated measures evaluated the cardiovascular response to exercise over 16 weeks in athletes recovering from SARS-CoV-2 infection. Athletes (n = 82) completed 2-5 repeat assessments at regulated intervals over 16 weeks post-SARS-CoV-2 infection. Data from 287 assessments (submaximal exercise tests; Modified Bruce protocol) are included. HR (bpm), systolic blood pressure (SBP) (mmHg) and rating of perceived exertion (RPE) (Borg scale 6-20) were measured. Rates of change in HR, SBP and RPE over time are reported. Submaximal exercise HR, SBP and RPE decreased significantly over 16 weeks (p < 0.01). There was a steeper rate of decline for HR and RPE ≤30 days compared to >30 days after SARS-CoV-2 infection: HR at Stage 3: ≤30 days -0.53 (0.01); >30 days -0.06 (0.02) and Stage 5: ≤30 days -0.77 (0.12); >30 days -0.12 (0.02); RPE at Stage 3: ≤30 days -0.09 (0.02); >30 days -0.01 (0.0002) and Stage 5: ≤30 days -0.13 (0.02); >30 days -0.02 (0.004). The findings provide clinical recommendation for exercise prescription and monitoring RPE in response to exercise post-SARS-CoV-2 infection and contribute to the clinical understanding of recovery which can help manage athlete expectations.

Physical Activity and Related Factors in Pre-Adolescent Southern African Children of Diverse Population Groups.

Tailored obesity management includes understanding physical activity (PA) and its context, ideally in childhood before the onset of health risk. This cross-sectional study determined, by sex and population, the PA of Southern African pre-adolescent urban primary school children. PA was measured objectively (step count: pedometer) and subjectively (Physical Activity Questionnaire for Older Children [PAQ-C]), taking confounders (phenotype, school-built environment, and socio-economic environment) into account. Body composition was measured with multifrequency bioelectrical impedance analysis (Seca mBCA). PA was adjusted for phenotypic confounders (body size and composition) using multivariate regression. Sex and population differences in PA were determined with two-way ANOVA. Ninety-four healthy pre-adolescents (60% girls, 52% black) with a similar socio-economic status and access to PA participated. Amidst phenotypic differences, average steps/day in girls (10,212) was lower than in boys (11,433) (p = 0.029), and lower in black (9280) than in white (12,258) (p < 0.001) participants. PAQ-C scores (5-point rating) were lower for girls (2.63) than boys (2.92) (p < 0.001) but higher for black (2.89) than white (2.58) (p < 0.001) participants. Objective and subjective measurements were, however, not significantly (r = −0.02; p = 0.876) related and PAQ-C failed to identify reactive changes in the step count. Objectively measured PA of black participants and of girls was consistently lower than for white participants and boys. Target-group specific interventions should therefore be considered.

Social Network Lifestyle Interventions Reduce Non-Communicable Diseases Risk Factors in Financial Sector Employees: Randomized Controlled Trial.

OBJECTIVE: To determine if scientifically based social network (Facebook) lifestyle interventions reduce 10-year cardiovascular disease (CVD) risk. METHODS: Financial sector employees (n = 300) were equally randomly assigned: Facebook plus Health Professionals (FB+HP), Facebook (FB), or control (C). We report changes in 10-year Framingham risk score (FRS) for CVD (%) and risk factors over 12 months. RESULTS: FRS did not change within and between groups. Overweight (-7.4% vs -5.6%, P  = 0.005) and diabetes risk (-10.7% vs 0.2%, P  = 0.011) reduced significantly in FB+HP versus FB and C, respectively. Inadequate fruit/vegetable intake (-9.4% vs 3.6%, P  = 0.011) and smoking (-0.7% vs 14.9%) reduced significantly in FB versus C. No significant changes in physical activity, central obesity, hypertension, and hypercholesterolemia between groups. CONCLUSIONS: Scientifically based social network lifestyle intervention programs could be included in workplace health promotional programmes to improve certain non-communicable disease risk factors.

Designing an integrated, nurse-driven and home-based digital intervention to improve insulin management in under-resourced settings.

BACKGROUND: In South Africa, initiating insulin for people with type 2 diabetes and subsequent titration is a major challenge for the resource-constrained healthcare system. Inadequate support systems in primary care, including not being able to access blood glucose monitors and test strips for self-monitoring of blood glucose, results in patients with type 2 diabetes being referred to higher levels of care. In primary care, initiation of insulin may be delayed due to a shortage of healthcare workers. The delayed initiation of insulin is also exacerbated by the reported resistance of both healthcare providers and people with type 2 diabetes to start insulin. In South Africa, telehealth provides an opportunity to overcome these challenges and manage insulin therapy in primary care. METHODS: We describe the development of a digital health intervention including the framework used, the theoretical approach and subsequent implementation strategies. RESULTS: This intervention is an innovative, nurse-driven and app-enabled intervention called 'the Tshwane Insulin Project intervention'. The Tshwane Insulin Project intervention was designed and evaluated using the framework recommended by the Medical Research Council for complex interventions. The Tshwane Insulin Project intervention was developed in four sequential phases: planning, design, implementation and evaluation. The Tshwane Insulin Project intervention followed the Integrated Chronic Disease Management framework to facilitate implementation and acceptability. The Tshwane Insulin Project comprises a facility-level intervention, where nurses evaluate patients and initiate insulin, an individual-level intervention where community healthcare workers visit patients at their homes to follow-up and provide educational information, while using telehealth to enable physician-directed insulin titration if needed, and a community-level intervention aimed at empowering community healthcare workers to support people living with diabetes and raise awareness of diabetes. CONCLUSION: The technological advancements in digital health and telemedicine present an opportunity to improve diabetes care in resource-limited countries. This work can inform those intending to develop and implement complex interventions in primary healthcare in developing countries.

Resting Energy Expenditure and Related Factors in 6- to 9-Year-Old Southern African Children of Diverse Population Groups.

Lower resting energy expenditure (REE) may partially explain the disproportionate prevalence of overweight/obesity among black African women. As no previous studies have investigated the REE of Southern African (South. Afr.) children, we aimed to determine, by sex and population group, the REE of 6- to 9-year-old urban school children. In a cross-sectional study with quota sampling, REE was measured with indirect calorimetry (IC). Confounders considered were: body composition (BC) (fat-free mass (FFM), FFM index, fat mass (FM), FM index), assessed using multifrequency bioelectrical impedance analysis, and physical activity (PA) measured with a pedometer. Multivariate regression was used to calculate REE adjusted for phenotypes (BC, z-scores of weight-for-age, height-for-age, body mass index-for-age) and PA. Sex and population differences in REE were determined with two-way ANOVA. Ninety-four healthy children (59.6% girls; 52.1% black) with similar socioeconomic status and PA opportunities participated. Despite BC variations, sex differences in REE were not significant (41 kcal/day; P = 0.375). The REE of black participants was lower than of white (146 kcal/day; P = 0.002). When adjusted for FFM and HFA z-score, the differences in REE declined but remained clinically meaningful at 91 kcal/day (P = 0.039) and 82 kcal/day (P = 0.108), respectively. We recommend the development of population-specific REE prediction equations for South. Afr. children.

Repeated Annual Health Risk Assessments With Intervention Did Not Reduce 10-year Cardiovascular Disease Risk: A 4-year Longitudinal Study in 13,737 Financial Sector Employees.

OBJECTIVE: To determine if repeat annual health risk assessments (RAHRAs) with intervention reduce 10-year cardiovascular disease (CVD) risk in financial sector employees. METHODS: Retrospective analysis from RAHRAs in 13,737 employees over 4 years. We report changes in 10-year FRS for CVD (%) and risk factors after 1 (GR1), 2 (GR2), and 3 (GR 3) RAHRAs. RESULTS: Mean FRS increased with RAHRAs (GR1: +0.4%; GR2: +0.7%; GR3: +0.8%) (P < 0.001) and was higher for GR3 versus GR1 (P < 0.001) and GR2 (pairwise: P < 0.0355). RAHRAs were associated with increased inadequate fruit/vegetable intake (GR1: +5.4%; GR2: +9.8%; GR3: +15.8%) (all pairwise: P < 0.001) and overweight (GR1: +5.4% vs GR2: +9.8%) (P < 0.001) and only hypercholesterolemia decreased (GR1: -4.4% vs GR3: -9.6%) (P < 0.001). CONCLUSION: RAHRAs did not reduce 10-year CVD risk in financial sector employees. Role of RAHRAs in chronic disease management requires further study.

Attitudes and beliefs of South African primary healthcare practitioners on initiating insulin in people with type 2 diabetes: Findings from the Tshwane Insulin Project (TIP).

AIMS: To investigate the attitudes and beliefs of primary healthcare practitioners (HCPs) towards initiating insulin therapy for people with type 2 diabetes (T2D) in South Africa. METHODS: A cross-sectional survey was conducted amongst HCPs from 23 clinics. The nurses' questionnaire was administered by research nurses while doctors completed an online version about their attitudes, beliefs and perceived barriers to initiating insulin. RESULTS: Of the 73 HCPs surveyed, 68% were nurses and 84% were women. Only 24% of HCPs believed that most patients would eventually need to initiate insulin regardless of their adherence to treatment regimens and 86% preferred to delay insulin therapy. Doctors were reluctant to initiate insulin, citing patient-related reasons such as low socio-economic level (41%), inability to refrigerate insulin (77%) and inability to self-monitor blood glucose (55%). Doctors mentioned that patient behaviour including not adhering to treatment regimen and appointments (91%) and reluctance to start insulin therapy (82%) influenced their prescription practices. Doctors mentioned that health system factors, including the pressure to see patients quickly (68%) and lack of continuity of care (64%) were barriers to initiating insulin. CONCLUSIONS: Optimising insulin therapy in primary care requires health system changes including promoting person-centred care and continuing training for HCPs.

Symptom cluster is associated with prolonged return-to-play in symptomatic athletes with acute respiratory illness (including COVID-19): a cross-sectional study-AWARE study I.

BACKGROUND: There are no data relating symptoms of an acute respiratory illness (ARI) in general, and COVID-19 specifically, to return to play (RTP). OBJECTIVE: To determine if ARI symptoms are associated with more prolonged RTP, and if days to RTP and symptoms (number, type, duration and severity) differ in athletes with COVID-19 versus athletes with other ARI. DESIGN: Cross-sectional descriptive study. SETTING: Online survey. PARTICIPANTS: Athletes with confirmed/suspected COVID-19 (ARICOV) (n=45) and athletes with other ARI (ARIOTH) (n=39). METHODS: Participants recorded days to RTP and completed an online survey detailing ARI symptoms (number, type, severity and duration) in three categories: 'nose and throat', 'chest and neck' and 'whole body'. We report the association between symptoms and RTP (% chance over 40 days) and compare the days to RTP and symptoms (number, type, duration and severity) in ARICOV versus ARIOTH subgroups. RESULTS: The symptom cluster associated with more prolonged RTP (lower chance over 40 days; %) (univariate analysis) was 'excessive fatigue' (75%; p<0.0001), 'chills' (65%; p=0.004), 'fever' (64%; p=0.004), 'headache' (56%; p=0.006), 'altered/loss sense of smell' (51%; p=0.009), 'Chest pain/pressure' (48%; p=0.033), 'difficulty in breathing' (48%; p=0.022) and 'loss of appetite' (47%; p=0.022). 'Excessive fatigue' remained associated with prolonged RTP (p=0.0002) in a multiple model. Compared with ARIOTH, the ARICOV subgroup had more severe disease (greater number, more severe symptoms) and more days to RTP (p=0.0043). CONCLUSION: Symptom clusters may be used by sport and exercise physicians to assist decision making for RTP in athletes with ARI (including COVID-19).

High Prevalence of Non-Communicable Diseases Risk Factors in 36,074 South African Financial Sector Employees: A Cross-Sectional Study.

OBJECTIVE: To determine the prevalence of non-communicable disease (NCD) risk factors, total NCD risk category and 10-year risk for cardiovascular diseases (CVD) in financial sector employees. METHODS: This descriptive observational cross-sectional analysis, data from 36,074 employees was analysed. NCD risk factor data was obtained from health risk assessments that included a questionnaire and clinical measures. The 10-year risk for CVD was calculated using the Framingham non-laboratory based equation. RESULTS: Inadequate fruit and vegetable intake (89.3%), insufficient physical activity (77.4%), and being overweight (66.8%) were the most prevalent risk factors. Women had significantly higher prevalence ratios for central obesity (2.28; P < 0.001), insufficient physical activity (1.21; P < 0.001), hypercholesterolaemia (1.15; P < 0.001), and overweight (1.08; P < 0.001) compared with men. CONCLUSION: A more concerted effort is required to provide employees with appropriate tools and education at the workplace to decrease and manage NCDs.

Epidemiology, clinical characteristics and severity of gradual onset injuries in recreational road cyclists: A cross-sectional study in 21,824 cyclists - SAFER XIII.

OBJECTIVES: Prevalence, clinical characteristics and severity of gradual onset injuries (GOIs) in cyclists are poorly documented. We determine the prevalence, anatomical regions/sites affected and severity of GOIs among entrants in a community-based mass participation event. DESIGN: Cross-sectional study; SETTING: Cape Town Cycle Tour; PARTICIPANTS: Race entrants. MAIN OUTCOME MEASURES: Of 35,914 entrants, 27,349 completed pre-race medical questionnaires. We studied 21,824 consenting cyclists (60.8% of entrants). Crude lifetime prevalence, retrospective annual incidence, anatomical region/sites, specific GOI, tissue type and GOI severity is reported. RESULTS: The lifetime prevalence of GOIs was 2.8%, with an annual incidence of 2.5%. More common anatomical regions affected by GOIs were lower limb (43.4%), upper limb (19.8%), and lower back (11.5%). The knee (26.3%), shoulder (13%), and lower back (11.5%) regions were mostly affected. The most common GOI was anterior knee pain (14.2%). Of the GOIs, 55% were in soft tissue. 50% of cyclists reported symptom duration >12 months, and 37.3% of GOIs were severe enough to reduce/prevent cycling. CONCLUSION: 2.5% recreational cyclists report a GOI annually. >50% of GOIs affect the knee, lower back and shoulder. GOIs negatively affect cycling. Risk factors related to GOIs in cyclists need to be determined to develop and implement prevention programs.

History of chronic disease is a novel intrinsic risk factor associated with gradual onset injuries in recreational road cyclists: A cross-sectional study in 21,824 cyclists - SAFER XIV.

OBJECTIVES: Risk factors related to Gradual onset injuries (GOIs) in cyclists need to be identified to enable effective injury prevention strategies. We aim to determine risk factors related to GOIs in cyclists participating in mass community-based events. DESIGN: Cross-sectional study. SETTING: Cape Town Cycle Tour. PARTICIPANTS: Race entrants (n = 35,914) MAIN OUTCOME MEASURES: Completion of pre-race medical questionnaires. 21,824 consenting cyclists (60.8%) were studied. 617 cyclists reported GOIs. Selected risk factors associated with GOIs: demographics, training/racing history, chronic disease history, and medication use, were explored using multi-variate analyses. RESULTS: Prevalence ratio (PR) of GOIs was similar in males and females, but higher in older age categories [>50 yrs vs. categories: ≤30yrs (PR = 1.6); 31 to ≤40yrs (PR = 1.5); 41 to <50yrs (PR = 1.4)] (p < 0.0001). Intrinsic risk factors associated with GOIs (adjusted for gender and age) were: 1) increased weekly training/racing frequency (PR = 1.1, p = 0.0003), 2) chronic disease history [cardiovascular disease symptoms (PR = 2.3, p = 0.0026), respiratory disease (PR = 1.6, p < 0.0001), nervous system/psychiatric disease (PR = 1.5, p = 0.0082)], and 3) history of analgesic/anti-inflammatory medication (AAIM) used before/during racing (PR = 5.1, p < 0.0001). CONCLUSION: Increased training frequency, chronic disease and AAIM use are risk factors associated with GOIs in cyclists. A novel finding is that in recreational cyclists, chronic disease history could be considered when managing GOIs and implementing prevention programs.

Willingness of people with Type 2 diabetes to start insulin therapy: Evidence from the South African Tshwane Insulin Project (TIP).

AIMS: To determine factors associated with 'hypothetical willingness' to start insulin among people with Type 2 diabetes (T2DM). METHODS: A quantitative cross-sectional study with insulin-naïve T2DM patients at 23 primary care facilities in the Tshwane Metropolitan Municipality. Data collected included demographic and clinical data, willingness to start insulin, attitudes and barriers to insulin therapy. Factors associated with unwillingness to start insulin therapy were explored using a multivariable logistic regression model. RESULTS: Of 468 T2DM study patients (mean age 57.2, SD = 11.3 years), more than half (51.9%) expressed unwillingness to starting insulin therapy. Unwillingness was associated with negative attitudes (OR = 1.32, 95% CI = 1.12-1.55, p = 0.001) and reluctance (OR = 1.41, 95% CI = 1.27-1.57, p < 0.001) rather than age, sex, education or diabetes duration. The strongest reasons for patient unwillingness were injection anxieties, fear of needles, insufficient knowledge of insulin, feeling unable to cope with insulin and concerns about out-of-pocket costs. CONCLUSIONS: The prospect of insulin therapy disturbs patients' sense of self and their psychological wellbeing. The high prevalence of psychological insulin resistance among these T2DM patients needs to be addressed for effective diabetes management.

Effect of Mixed Basic Military Training on the Physical Fitness of Male and Female Soldiers.

INTRODUCTION: Mixed gender basic military training (BMT) is adopted to integrate the female South African soldier into the military. This study aimed to assess gender differences before, during (12 weeks), and after a 20-week mixed BMT course and determine if BMT significantly reduced these differences. METHODS: A total of 186 soldiers (114 male: mean age = 21.0 ± 1.1 year; 72 female: mean age = 20.5 ± 1.2 year) completed the BMT course and all anthropometric, physical fitness, explosive power, and hand grip strength measurements. Repeated-measures analysis of variance was used to model BMT data with main effects for gender comparison between males and females, and time main effect for evaluation of differences between weeks 1, 12, and 20 of BMT, as well as an interaction effect for differences in changes over time for males and females. Alpha was set at α ≤0.05. RESULTS: Male soldiers were significantly taller (p < 0.001) and scored better in all measurements at the start of BMT, differences ranged from 1.6% to 50% between genders. Differences narrowed by up to 18.5% in aerobic, push-up, abdominal measurements, and to 4.6% in the South African National Defense Force fitness test. Differences in power output and hand grip strength remained unchanged. CONCLUSION: Large initial anthropometrical and physical fitness differences decreased but were still obvious at the end of BMT. BMT should bridge the physical gap between male and female soldiers to ensure they can all perform the same duties. The enforcing of equal minimum physical fitness requirements for acceptance into BMT; conditional acceptance into the military subject to the successful completion of a bridging course aimed at improving physical fitness in individuals who do not meet the minimum physical fitness requirements for acceptance; and developing a cyclic physical training program with different entry points, dependent on initial physical performance at the start of BMT, ensuring adequate progression and overload for all soldiers are possible avenues to explore to achieve this goal.

The Difference Between Exercise-Induced Autonomic and Fitness Changes Measured After 12 and 20 Weeks of Medium-to-High Intensity Military Training.

Grant, CC, Mongwe, L, Janse van Rensburg, DC, Fletcher, L, Wood, PS, Terblanche, E, and du Toit, PJ. The difference between exercise-induced autonomic and fitness changes measured after 12 and 20 weeks of medium-to-high intensity military training. J Strength Cond Res 30(9): 2453-2459, 2016-The aim of this study was to compare the physical fitness, based on VO2max and exercise-induced cardiac autonomic changes, measured by heart rate variability (HRV) of 12 weeks with 20 weeks of training in the South African National Defence Force. Recruits (n = 154) participated in a medium-to-high intensity exercise intervention (daily energy expenditure: 8,485 kJ·d). The significant effect on VO2max between weeks 1 and 12 (48.57, SD = 9.25 vs. 53.36, SD = 7.21] did not continue during weeks 12-20 (53.36, SD = 7.21 vs. 53.87, SD = 7.87). No changes in the supine low frequency (LF)/high frequency (HF) (0.48, SD = 0.51 vs. 0.41, SD = 0.64) or the standing LF/HF (4.02, SD = 5.14 vs. 3.91, SD = 5.28), an indicator of autonomic balance and a possible indicator of overtraining syndrome, suggests that overtraining did not take place during weeks 12-20. This was confirmed with further decreases in supine and standing heart rate. However, the power of the vagal-induced variability continued to increase after 12 weeks. Increased vagal influence without concurrent change in autonomic balance may be interpreted as decreased sympathetic cardiac control. It is important to note that although no fitness changes were detected, positive cardiac autonomic conditioning did continue between weeks 12 and 20, as measured by increased vagal-induced HRV and decreased sympathetic influence on cardiac control. Results may be extrapolated to training in the normal population/athletes after a medium-to-high intensity exercise program, as this intervention was a closely monitored and standardized exercise program.

Mechanical properties of the triceps surae: differences between football and non-football players.

We investigated the mechanical properties of the triceps surae between professional, junior, and non-football players. Fifty-nine men participated in this study. The mechanical properties of the right legs' triceps surae were measured in vivo using a free oscillation technique; no significant differences existed between the groups. The mean results for musculo-articular stiffness, damping coefficient, and damping ratio were as follows: professional football players (21523 N· m⁻¹, 330.8 N · s · m⁻¹, and 0.201); junior football players (21063 N · m⁻¹, 274.4 N · s · m⁻¹, and 0.173); and non-players (19457 N · m⁻¹, 281.5 N · s · m⁻¹, and 0.184). When analysed according to position, the results were as follows: defender (21447 N · m⁻¹, 308.6 N · s · m⁻¹, and 0.189); midfielder (20762 N · m⁻¹, 250.7 N · s · m⁻¹, and 0.157); winger (21322 N · m⁻¹, 335.1 N · s · m⁻¹, and 0.212); forward (22085 N · m⁻¹, 416.2 N · s · m⁻¹, and 0.254); and non-players (19457 N · m⁻¹, 281.5 N · s · m⁻¹, and 0.184). Thus, football training, football games, and the position played had no effect on triceps surae mechanical properties. These results may be attributed to opposing adaptations between different types of training that are usually implemented in football. Alternatively, the minimum strain amplitude and/or frequency threshold of the triceps surae required to trigger adaptations of mechanical properties might not be achieved by football players with football training and matches.

Heart rate variability assessment of the effect of physical training on autonomic cardiac control.

BACKGROUND: The effect of exercise interventions on autonomic nervous system (ANS) control of the heart by heart rate variability (HRV) is often investigated in just one position. It was hypothesized that results of exercise-induced changes on ANS are dependent on body position and that it is possible to distinguish between exercise induced changes in vagal and sympathetic influence by taking measurements in different body positions. METHODS: One hundred eighty-three (male = 100, female = 83) healthy volunteers, between 18 and 22 years, participated in a prospective twelve week medium to high intensity exercise intervention study with a self-control design. The influence of the exercise intervention was investigated on supine, rising, and standing as well as on the orthostatic response. Time domain, frequency domain and nonlinear (Poincaré) HRV analysis were performed. RESULTS: The exercise intervention lead to a significant increase (P < 0.05) in vagal influence during supine, rising, and standing. Sympathetic control in the supine position was decreased and increased during rising and standing. In the initial orthostatic response to rising from the supine position, the exercise intervention lead to increased (P < 0.05) vagal withdrawal as well as increased sympathetic control. The orthostatic response measured as the difference between standing and supine indicated only an exercise induced increase in sympathetic control. CONCLUSIONS: Exercise-induced changes in sympathetic and parasympathetic ANS control differ, depending on posture and period of measurement. Exercise induced changes in parasympathetic and sympathetic outflow, respectively, can be extracted from measurements from supine, through the orthostatic response, to standing, thereby detecting changes in ANS that are otherwise obscured.