Effects of extra school‐based physical education on overall physical fitness development – the CHAMPS study DK

First, this study aimed to investigate if four extra physical education (PE) lessons per week improved children's development in physical fitness. Second, to investigate if the extra PE lessons improved development in physical fitness for children with lower levels of fitness at baseline. This study was a longitudinal controlled school‐based study. The study population consisted of 10 Danish public schools with children in preschool to fourth grade (cohorts 0–4) with 2.5‐year follow‐up. Six schools had extra PE and four schools had normal PE. In total 1247 children were included (normal PE = 536, extra PE = 711). Development in fitness was analyzed using a composite z‐score from six fitness tests. Multilevel mixed‐effects linear regression was used to examine the association between school type and development in fitness. Extra PE increased the total development of composite z‐score units among children enrolled in cohort 4 and borderline in cohort 3 with 1.06 (95% confidence interval 0.48–1.65) and 0.52 z‐score units (?0.06 to 1.09), respectively. Children in the lower 50 percentiles increased their development with 0.47 (0.08–0.85) z‐score units. Extra PE in schools improved development in fitness for cohort 4 and borderline for cohort 3 among all children. Extra PE improved fitness development across all cohorts among children with low fitness levels.     

Does physical education influence eye‐hand coordination? The Lifestyles of our Kids intervention study

In Australian government‐funded primary schools, the responsibility for physical education (PE) falls mainly on general classroom teachers, many of whom possess limited PE training. This study sought to examine the impact of specialist‐taught PE on eye‐hand coordination (EHC) development. In this 4‐year cluster‐randomized intervention, participants were 187 boys and 172 girls initially in grade 2 in 29 primary schools, where no school employed university‐trained specialist PE teachers. In 13 (intervention) schools, specialist PE teachers conducted 268 PE classes (two 45‐minute sessions/wk) from grade 2 to grade 6. The intervention was based on traditional PE educational objectives, including fundamental motor skills, but did not specifically focus on EHC. The remaining 16 (control) schools continued with common‐practice PE taught by general classroom teachers (30‐60 min/wk). EHC was measured by a ball throw and wall‐rebound catch test and recorded at ages 8, 10, and 12 (SD 0.3) at ends of grades 2, 4, and 6, respectively. There was steady yearly improvement of EHC in both groups, but no evidence of any intervention effect in boys (P=.88) or girls (P=.20). The introduction of specialist‐taught PE during 4 years of primary school did not influence EHC development. Considering evidence that classroom teachers make little contribution to PE in this jurisdiction, together with the steady progression of EHC over the 4 years, other influences such as organized sport, after‐school activities, natural development, and parental instruction are conceivably more influential factors in EHC development during primary school years.     

Hypertrophic effect of inhaled beta2‐agonist with and without concurrent exercise training: A randomized controlled trial

Due to a high prevalence of asthma and exercise‐induced bronchoconstriction in elite athletes, there is a high use of beta₂‐adrenoceptor agonists (beta₂‐agonists) in the athletic population. While anabolic in rodents, no study has been able to detect hypertrophy in humans after chronic beta₂‐agonist inhalation. We investigated whether inhaled beta₂‐agonist, terbutaline, alters body composition and metabolic rate with and without concurrent exercise training in healthy young men. Sixty‐seven participants completed a 4‐week intervention of daily terbutaline (8 × 0.5 mg) or placebo treatment without concurrent training (habitual; n = 23), with resistance (n = 23) or endurance (n = 21) training 3 times weekly. Before and after the interventions, participant's body composition was determined by dual‐energy X‐ray absorptiometry and resting metabolic rate and substrate oxidation by indirect calorimetry. Terbutaline increased lean body mass by 1.03 kg (95% CI 0.29‐1.76; P  < .05) and 1.04 kg (95% CI 0.16‐1.93; P  < .05) compared to placebo in the habitual and resistance training group, respectively, but had no effect compared to placebo in the endurance training group [−0.56 kg (95% CI −1.74‐0.62; P  > .05)]. Fat mass, bone mineral content, and resting metabolic rate did not change differently between treatments with the intervention. Daily inhalation of terbutaline in near‐therapeutic doses induces skeletal muscle growth. This observation should be a concern for antidoping authorities.     

Effect of a school environment intervention on adolescent adiposity and physical fitness

The aim of this study was to evaluate the effect of an intervention targeting the physical and organizational school environment for noncurricular physical activity (SPACE) on adiposity, aerobic fitness, and musculo‐skeletal strength in Danish adolescents. The study used a cluster randomized controlled design. Fourteen schools and 1348 adolescents aged 11–14 years were included at baseline. Seven schools were randomized to the intervention, which was designed to change the organizational and physical environment of the school. The analysis revealed no significant differences between the adolescents in the intervention group compared to the comparison group after a 2‐year follow‐up. Adjusted for baseline, sex, age, and clustering within schools, the difference between the intervention schools compared to the comparison schools was 6 m in the shuttle run test [95% confidence interval (CI): ?21; 33], 0.2 cm in waist circumference (95% CI: ?2.6; 3.1), and ?1.1 kg in handgrip strength (95% CI: ?2.2; ?0.1). The results did not provide evidence for the effect of the intervention on adiposity, aerobic fitness, or musculo‐skeletal strength in adolescents. Reasons for not finding an effect could be related to both the design and the implementation of the intervention.     

Longitudinal influence of musculo‐skeletal injuries and extra physical education on physical fitness in schoolchildren

The aims of this study were to investigate if (A) injuries and (B) increased physical education (PE) influenced the development of physical fitness in schoolchildren. Simultaneously, to investigate if a possible PE effect was modified by sport participation outside school hours. This was a longitudinal controlled school‐based study. Six schools with 270 min of PE (extra PE) and four schools with 90 min of PE were followed up for 2.5 years. In total, 1054 children were included for analysis (normal PE = 443, extra PE = 611). Development in fitness was analyzed using composite z‐scores from six fitness tests measured four times. Information of injury and sport was derived from weekly automated mobile phone text messages surveying the presence of musculo‐skeletal pain and organized sport participation. Injury and extra PE both influenced the development of physical fitness. Injury decreased development of physical fitness with ?1.01 composite z‐score units (95% CI: ?1.57; ?0.45). Extra PE increased physical fitness development with 0.80 (95% CI: 0.49; 1.10) composite z‐score units. The influence of injury was not dependent on extra PE. No modifying effect was found by mean weekly sport participation outside school hours. In conclusion, extra PE had a positive effect, whereas injuries had a negative effect on physical fitness development in schoolchildren.     

Social background,bullying, and physical inactivity: National study of 11‐ to 15‐year‐olds

More children from lower social backgrounds are physically inactive than those from higher ones. We studied whether bullying was a mediating factor between lower social background and physical inactivity. We also examined the combined effect of low social class and exposure to bullying on physical inactivity. The Danish sample of the Health Behaviour in School‐aged Children (HBSC) study 2006 included 6269 schoolchildren in three age groups: 11‐, 13‐, and 15‐year‐olds from a random sample of 80 schools. The students answered the internationally standardized HBSC questionnaire. The applied definition leaves 4.0% in the category physically inactive. The sex and age‐adjusted OR (95% CI) for physical inactivity was 2.10 (1.39–3.18) among students with low social class and unclassifiable 3.53 (2.26–5.53). Exposure to bullying was associated with physical inactivity, sex and age‐adjusted OR = 2.39 (1.67–3.41). Exposure to bullying did not explain the association between social class and physical inactivity. The association between social class and physical inactivity was more pronounced among participants also exposed to bullying. In conclusion, there was a significantly increased odds ratio for physical inactivity among students from lower social classes and for students exposed to bullying. There was a combined effect of low social class and bullying on physical inactivity.     

Evaluation of a two-year middle-school physical education intervention: M-SPAN

PURPOSE: School physical education (PE) is highly recommended as a means of promoting physical activity, and randomized studies of health-related PE interventions in middle schools have not been reported. We developed, implemented, and assessed an intervention to increase physical activity during middle-school PE classes. METHODS: Twenty-four middle schools (approximately 25,000 students, 45% nonwhite) in Southern California participated in a randomized trial. Schools were assigned to intervention (N = 12) or control (N = 12) conditions, and school was the unit of analysis. A major component of the intervention was a 2-yr PE program, which consisted of curricular materials, staff development, and on-site follow-up. Control schools continued usual programs. Student activity and lesson context were observed in 1849 PE lessons using a validated instrument during baseline and intervention years 1 and 2. RESULTS: The intervention significantly (P = 0.02) improved student moderate to vigorous physical activity (MVPA) in PE, by approximately 3 min per lesson. Effects were cumulative; by year 2 intervention schools increased MVPA by 18%. Effect sizes were greater for boys (d = 0.98; large) than girls (d = 0.68; medium). CONCLUSIONS: A standardized program increased MVPA in middle schools without requiring an increase in frequency or duration of PE lessons. Program components were well received by teachers and have the potential for generalization to other schools. Additional strategies may be needed for girls.     

A monitoring system to provide feedback on student physical activity during physical education lessons

School‐based physical education (PE) provides opportunities to accumulate moderate‐to‐vigorous physical activity (MVPA), but many students are insufficiently active during PE lessons. Providing teachers with feedback regarding their students’ physical activity may increase the effectiveness of PE for achieving MVPA goals, but existing physical activity monitoring technologies have limitations in class environments. Therefore, the purpose of this study was to develop and validate a system capable of providing feedback on PE lesson MVPA. Equations for translating step counts to %MVPA were derived from measures in 492 students who concurrently wore an ActiGraph GT3X+ (ActiGraph) and Yamax pedometer (Yamax) during a PE lesson. To enhance feedback availability during PE lessons, we then developed a bespoke monitoring system using wireless tri‐axial pedometers (HMM) and a smart device app. After developing and testing the monitoring system, we assessed its validity and reliability in 100 students during a PE lesson. There was a strong correlation of 0.896 between step counts and accelerometer‐determined %MVPA and quantile regression equations showed good validity for translating step counts to %MVPA with a mean absolute difference of 5.3 (95% CI, 4.4‐6.2). The physical activity monitoring system was effective at providing %MVPA during PE lessons with a mean difference of 1.6 ± 7.1 compared with accelerometer‐determined %MVPA (7% difference between the two measurement methods). Teachers and students can use a smart device app and wireless pedometers to conveniently obtain feedback during PE lessons. Future studies should determine whether such technologies help teachers to increase physical activity during PE lessons.     

Knee function among elite handball and football players 1‐6 years after anterior cruciate ligament injury

The aim of the study was to describe objective and self‐reported knee function for athletes who have returned to elite handball and football play after an ACL injury, comparing these to non‐injured players at the same level. A total of 414 handball and 444 football players completed baseline tests from 2007 through 2014, examining lower extremity strength, dynamic balance, knee laxity, and knee function (KOOS questionnaire). Measures were compared between injured and non‐injured legs and between injured legs and legs of controls. Eighty (9.3%) of the 858 players reported a previous ACL injury, 1‐6 years post‐injury (3.5±2.5 years), 49 handball (61.3%) and 31 football players (38.7%). We found no difference in strength or dynamic balance between previously ACL‐injured (N=80) and non‐injured players legs (N=1556). However, lower quadriceps (6.3%, 95% CI: 3.2‐9.2) and hamstrings muscle strength (6.1%, 95% CI: 3.3‐8.1) were observed in previously ACL‐injured legs compared to the non‐injured contralateral side (N=80). ACL‐injured knees displayed greater joint laxity than the contralateral knee (N=80, 17%, 95% CI: 8‐26) and healthy knees (N=1556, 23%, 95% CI: 14‐33). KOOS scores were significantly lower for injured knees compared to knees of non‐injured players. ACL‐injured players who have successfully returned to elite sport have comparable strength and balance measures as their non‐injured teammates. Subjective perception of knee function is strongly affected by injury history, with clinically relevant lower scores for the KOOS subscores Pain, Function, Sport, and Quality Of Life.     

High ankle injury rate in adolescent basketball: A 3‐year prospective follow‐up study

This prospective study investigated the incidence and pattern of acute time‐loss injuries in young female and male basketball players. Eight basketball teams (n=201; mean age 14.85±1.5) participated in the follow‐up study (2011‐2014). The coaches recorded player participation in practices and games on a team diary. A study physician contacted the teams once a week to check new injuries and interviewed the injured players. In total, 158 injuries occurred. The overall rate of injury (per 1000 hours) was 2.64 (95% CI 2.23‐3.05). Injury rate was 34.47 (95% CI 26.59‐42.34) in basketball games and 1.51 (95% CI 1.19‐1.82) in team practices. Incidence rate ratio (IRR) between game and practice was 22.87 (95% CI 16.71‐31.29). Seventy‐eight percent of the injuries affected the lower limbs. The ankle (48%) and knee (15%) were the most commonly injured body sites. The majority of injuries involved joint or ligaments (67%). Twenty‐three percent of the injuries were severe causing more than 28 days absence from sports. Number of recurrent injuries was high (28% of all injuries), and most of them were ankle sprains (35 of 44, 79%). No significant differences were found in injury rates between females and males during games (IRR 0.88, 0.55, to 1.40) and practices (IRR 1.06, 0.69, to 1.62). In conclusion, ankle and knee ligament injuries were the most common injuries in this study. Moreover, the rate of recurrent ankle sprains was alarming.     

Self‐reported health‐enhancing physical activity recommendation adherence among 64,380 finnish adults

The Finnish recommendations for health‐enhancing physical activity (PA) for adults (≥18 years) recommend: (i) ≥150 minutes of moderate‐to‐vigorous‐intensity physical activity (MVPA) and (ii) activities that develop muscle strength and balance ≥2 days/week. However, adherence to these recommendations among the Finnish adults is currently unknown. This study reports on the self‐reported adherence to the PA recommendations and associations with sociodemographic factors among Finnish adults. Data were used from the Finnish “Regional Health and Well‐being Study.” In 2013‐2014, postal questionnaires were sent to 132,560 persons, with 69,032 responding (response rate =52.1%). The weighted proportions adhering to the: (i) MVPA recommendation, (ii) sufficient muscle‐strengthening activity (≥2 days/week), (iii) sufficient balance training (≥2 days/week), and (iv) Finnish health‐enhancing PA recommendations (Finnish recommendations) were calculated. Associations with sociodemographic variables (eg, age, education level, self‐rated health) were assessed using multiple logistic regression analyses. Of 69,032 respondents, 92.6% (n=64,380, response rate =48.6%, 18‐98 years) reported on their physical activity levels. A total of 31.2% (95% CI: 30.8%‐31.6%) met the aerobic MVPA recommendation, 17.2% (95% CI: 16.9%‐17.6%) reported sufficient muscle‐strengthening activity, 6.7% (95% CI: 6.4%‐6.9%) reported sufficient balance training, and 10.8% (95% CI: 10.5%‐11.1%) met the Finnish recommendations. In the adjusted analysis, those with poorer self‐rated health, older age, lower education levels, and those classified overweight or obese were independently associated with lower odds of meeting the Finnish recommendations. The vast majority of Finnish adults do not meet the full PA recommendations. Public health action is needed to increase PA in Finland.     

Acute high‐intensity football games can improve children's inhibitory control and neurophysiological measures of attention

Recent studies suggest that a single bout of exercise can lead to transient performance improvements in specific cognitive domains in children. However, more knowledge is needed to determine the key exercise characteristics for obtaining these effects and how they translate into real‐world settings. In the present study, we investigate how small‐sided football games of either high‐ or moderate‐intensity affect measures of inhibitory control in a school setting. Eighty‐one children (mean age 11.8, 48 boys) were randomly allocated to three groups performing 20‐minute of high‐intensity small‐sided real football games (SRF), moderate‐intensity small‐sided walking football games (SWF) or resting (RF). Behavioral measures of inhibitory control and neurophysiological measures of attention (P300 latency and amplitude) were obtained during a flanker task performed at baseline and 20 minutes following the intervention. Retention of declarative memory was assessed in a visual memory task 7 days after the intervention. Measures of inhibitory control improved more in children performing SRF compared to SWF 19 ms, 95% CI [7, 31 ms] (P = 0.041). This was paralleled by larger increases in P300 amplitudes at Fz in children performing SRF compared both to RF in congruent (3.54 μV, 95% CI [0.85, 6.23 μV], P = 0.039) and incongruent trials (5.56 μV, 95% CI [2.87, 8.25 μV], P < 0.001) and compared to SWF in incongruent trials (4.10 μV, 95% CI [1.41, 6.68 μV], P = 0.010). No effects were found in measures of declarative memory. Together this indicates that acute high‐intensity small‐sided football games can transiently improve measures of inhibitory control and neurophysiological correlates of attention. Intense small‐sided football games are easily implementable and can be employed by practitioners, for example, during breaks throughout the school day.     

Validity of the SMS,Phone, and medical staff Examination sports injury surveillance system for time‐loss and medical attention injuries in sports

The accurate measurement of sport exposure time and injury occurrence is key to effective injury prevention and management. Current measures are limited by their inability to identify all types of sport‐related injury, narrow scope of injury information, or lack the perspective of the injured athlete. The aims of the study were to evaluate the proportion of injuries and the agreement between sport exposures reported by the SMS messaging and follow‐up telephone part of the SMS , Phone, and medical staff Examination (SPE x) sports injury surveillance system when compared to measures obtained by trained on‐field observers and medical staff (comparison method). We followed 24 elite adolescent handball players over 12 consecutive weeks. Eighty‐six injury registrations were obtained by the SPE x and comparison methods. Of them, 35 injury registrations (41%) were captured by SPE x only, 10 injury registrations (12%) by the comparison method only, and 41 injury registrations (48%) by both methods. Weekly exposure time differences (95% limits of agreement) between SPE x and the comparison method ranged from −4.2 to 6.3 hours (training) and −1.5 to 1.0 hours (match) with systematic differences being 1.1 hours (95% CI 0.7 to 1.4) and −0.2 (95% CI −0.3 to −0.2), respectively. These results support the ability of the SPE x system to measure training and match exposures and injury occurrence among young athletes. High weekly response proportions (mean 83%) indicate that SMS messaging can be used for player measures of injury consequences beyond time‐loss from sport. However, this needs to be further evaluated in large‐scale studies.     

Validation of body composition using bioelectrical impedance analysis in children according to the degree of obesity

This study aimed to validate body composition analysis using bioelectrical impedance analysis (BIA ) against dual‐energy X‐ray absorptiometry (DXA ) in children with obesity and to compare agreement between BIA and DXA according to their degree of obesity. Three hundred and sixteen children aged 6‐17 years participated in the Intervention for Childhood and Adolescents Obesity via Activity and Nutrition study. We divided participants by body mass index (BMI ) percentile (group 1: mild to moderate obesity; group 2: severe obesity) and compared body composition variables, eg, percentage of body fat (%BF ), fat mass (FM ), and fat‐free mass (FFM ) using BIA and DXA . The %BF and FM of BIA were significantly lower (−1.8% and −0.8 kg, respectively), and the FFM of BIA was significantly higher (1.4 kg) than those of DXA . There were significant negative relationships between the absolute value of differences from BIA and DXA and BMI z‐scores in %BF , FM , and FFM (regression coefficient [β]: −1.39, 95% confidence interval [CI ]: −1.81 to −0.97; β: −0.34, 95%CI : −0.61 to −0.06; β: −0.73, 95%CI : −1.03 to −0.44, respectively). The gap of body compositions between BIA and DXA decreased as participants became more obese, and the differences of FM in boys with severe obesity and the differences of %BF and FFM in girls with severe obesity were much less than those in children with mild to moderate obesity. In conclusion, the agreement between DXA and BIA was better for children with severe obesity than for children with mild to moderate obesity.     

The prevalence and severity of health problems in youth elite sports: A 6‐month prospective cohort study of 320 athletes

Little is known regarding the overall health of youth elite athletes. Our aim was to describe the prevalence and severity of health problems in a cohort of youth elite athletes representing a variety of endurance, team, and technical sports. Elite sport athletes (N = 260, 16.2 years) from different Sport Academy High Schools in Norway, and a group of their teammates (N = 60, 16.4 years) attending regular high schools, were included in the study. The Oslo Sports Trauma Research Centre (OSTRC ) questionnaire on health problems was used to self‐report injuries and illnesses for 26 weeks. At any given time, an average of 43% [95% CI : 37%‐49%] of the elite sport athletes had some form of health problem and 25% [20%‐31%] had substantial health problems. The prevalence of health problems was similar between the elite team sport athletes and their teammates, except for substantial injuries (22% [16%‐30%] vs 10% [5%‐20%]). Endurance sport athletes reported more illnesses (23% [15%‐35%]) than technical and team sport athletes (10% [5%‐20%] and 8% [4%‐14%]). In contrast, technical and team sport athletes reported more injuries (36% [95% CI : 25‐48] and 37% [95% CI 29‐45]) compared to endurance sport athletes (15% [8%‐25%]). The total impact of health problems was roughly split in thirds between overuse injuries (37%), acute injuries (34%), and illnesses (30%). This is the first prospective study to present self‐reported injury and illness data in a large heterogeneous group of youth elite athletes, documenting a substantial impact of both injuries and illnesses on the health of this population.     

Predictors of in‐school and out‐of‐school sport injury prevention: A test of the trans‐contextual model

The current study aimed to predict secondary school students’ motivation toward sport injury prevention in “in‐school” and “out‐of‐school” contexts, and their sport injury prevention behavior at 3‐month follow‐up using the trans‐contextual model (TCM). Hong Kong secondary school students (N = 1566; mean age = 13.34 years, range = 11 to 19; female = 49.42%) were recruited. Participants were asked to complete a survey comprising previously validated scales measuring TCM constructs at baseline and a measure of sport injury prevention behavior at follow‐up three months later. Structural equation modeling (SEM) was used to examine the hypothesized paths among TCM constructs. A SEM specifying hypothesized paths among TCM variables showed acceptable fit with the data (χ²(29) = 418.55, CFI = .93, TLI = .90, and RMSEA = .09, 90% CI [.09, .10], and SRMR = .05). Findings supported tenets of the TCM: the effects of perceived autonomy support from PE teachers on in‐school autonomous motivation toward injury prevention, the trans‐contextual relationship between students' “in‐school” and “out‐of‐school” autonomous motivation toward injury prevention, and the effects of autonomous motivation toward injury prevention on social cognitive variables and subsequent sport injury prevention behaviors. Results supported the tenets proposed within the TCM in predicting students' “in‐school” and “out‐of‐school” autonomous motivation toward sport injury prevention. Findings underscore the potential importance of autonomy support from PE teachers in facilitating students’ sport injury prevention behaviors. Further longitudinal and intervention research is warranted to establish temporal and causal effects of TCM variables in sport injury prevention.     

Combining higher-load and lower-load resistance training exercises: A systematic review and meta-analysis of findings from complex training studies

ObjectivesThe aim of the present meta-analytical review was to determine the effectiveness of training programmes combining higher-load and lower-load exercises in one workout (i.e. complex training [CT]) on lower-body performance.DesignSystematic review and meta-analysis.MethodsA search of five electronic databases (PubMed, Web of Science, SportDiscus, CINAHL and Scopus) was conducted to identify all publications up to 7 March 2018. Meta-analyses were performed using a random-effects model with the dependent variables countermovement jump (CMJ) height, squat jump (SJ) height, one-repetition maximum (1-RM) squat performance and sprint time for 5 m, 10 m, 20 m, 30 m and 40 m, respectively.ResultsThe analysis comprised 33 studies and a total of 1064 healthy participants. The meta-analysis revealed that CT is effective in improving CMJ (95% confidence interval [CI] 5.6%–12.3%), SJ (95% CI 8.0%–17.4%), 1-RM squat (95% CI 16.4%–30.7%) and sprint performance (5 m = 95% CI −14.8% to −0.9%, 10 m = 95% CI −6.0% to −2.1%, 20 m = 95% CI −7.4% to −1.4%, 30 m = 95% CI −8.0% to −0.6%). However, when directly compared to traditional training methods, only 1-RM squat strength performance and 20 m sprint time were superior following CT interventions (95% CI 0.2%–13.7% and 95% CI −1.6% to −0.1%, respectively)ConclusionsCT is an acceptable method for improving jump, strength and sprint performance in athletes. Compared to traditional training methods, CT seems to produce superior training effects only for 1-RM squat and 20 m sprint performance; however, these findings were influenced by single studies and should be therefore interpreted with circumspection.     

Self‐rated physical fitness and estimated maximal oxygen uptake in relation to all‐cause and cause‐specific mortality

This study investigated the longitudinal associations of self‐rated physical fitness and estimated maximal oxygen uptake (VO2max) with all‐cause and cause‐specific mortality. A total of 59 741 participants in the Finnish National FINRISK Study Cohort had data on self‐rated physical fitness and covariates. A subsample of 4823 participants had estimated VO2max data. Follow‐up ranged from 3 to 38 years. Associations of self‐rated physical fitness and VO2max with mortality were analyzed using multivariate Cox proportional hazard models. The study showed that poor self‐rated physical fitness was related to all‐cause mortality (hazard ratio [HR] 1.9; 95% confidence interval [CI] 1.8‐2.0) and mortality due to cardiovascular (HR 2.0, 95% CI 1.9‐2.2), cerebrovascular (HR 1.9, 95% CI 1.6‐2.2) and respiratory diseases (HR 2.1, 95% CI 1.9‐2.4), trauma (HR 1.7, 95% CI 1.3‐2.0), infections (HR 1.8, 95% CI 1.3‐2.7), dementia (HR 1.9, 95% CI 1.6‐2.3), and cancer (HR 1.7, 95% CI 1.5‐1.9). Coexisting higher age, physical inactivity, male gender, and severe chronic conditions further increased the risk. In men, higher VO2max was associated with a lower risk of lung cancer mortality (HR 0.8, 95% CI 0.7‐0.96). Based on the results, s elf‐rated physical fitness reflects a combination of unfavorable biological and lifestyle‐related factors, which increase mortality risk. A simple question about perceived physical fitness may reveal at‐risk individuals who would benefit from more intensive treatment of chronic conditions and other interventions aiming to promote better fitness and well‐being.     

Dose‐response effects of exercise on bone mineral density and content in post‐menopausal women

Exercise is one of the most widely used non‐pharmacological strategies to prevent bone resorption during menopause. Given the detrimental consequences of bone demineralization, the purpose of this study was to examine the effects of prescribing different exercise volumes on bone mineral density and content in previously inactive, post‐menopausal women during a 12‐month intervention and 1 year after intervention completion. Four hundred post‐menopausal women were randomized to either 150 min/wk (MODERATE dose group) or 300 min/wk (HIGH dose group) of aerobic exercise. Total bone mineral density (g/cm²) and bone mineral content (g) were assessed at baseline, 12 months (end of the intervention) and 24 months (follow‐up) using whole body dual‐energy X‐ray absorptiometry. At 12 months, mean bone mineral density among women in the HIGH dose group was estimated to be 0.006 g/cm² (95% CI: 0.001‐0.010; P = 0.02) higher than that of women randomized to the MODERATE dose group. At 24 months, the mean difference between groups remained statistically significant, indicating higher mean bone mineral density among women in the HIGH dose group (0.007 g/cm²; 0.001‐0.001; P = 0.04). No significant differences between groups were found at any time point for bone mineral content. In an exploratory analysis, women who completed more min/wk of impact exercises had significantly higher mean levels of bone mineral density at 12 months compared to baseline (0.006 g/cm², 95% CI: 0.006‐0.012; P = 0.03). These findings suggest that higher volumes of exercise, especially impact exercise, lead to a smaller decline in total bone mineral density, which may remain following intervention completion.