Association between physical activity and sickness absenteeism in university workers

BACKGROUND

Sedentary occupations have increased by more than 10% in Western countries over the last two decades, and the yearly global cost of physical inactivity has been estimated to be $53.8 billion. As workers tend to move less in the workplace, they are more likely to develop a sedentarism-related chronic condition and to be absent from work due to illness, although research evidence on the issue remains unclear.

AIMS

To investigate associations between physical activity (PA) and sickness absenteeism in the workplace among Spanish university workers.

METHODS

We conducted cross-sectional research with data from 1025 workers aged 18-65 years (43% women) from a Spanish university. Physical Activity Vital Sign (PAVS) and International Physical Activity Questionnaire (IPAQ) short versions were used to evaluate levels of PA. Workplace absenteeism was self-reported by participants. Written questionnaires distributed during medical checks included PAVS, IPAQ and the question about absenteeism among other information. The association between PA and sickness absenteeism was examined using adjusted multiple linear regression.

RESULTS

After adjusting for age, sex, job function, chronic conditions, sedentarism and smoking, each weekly hour of PA reduced sickness absence by -1.20 (95% confidence interval: -2.40-0.00) days per year.

CONCLUSIONS

The implementation of PA promotion strategies aimed at university employees may lead to a reduction of days off work due to illness.

ACTN3 R577X polymorphism related to sarcopenia and physical fitness in active older women

BACKGROUND

As the population is getting older, physical activity promotion becomes a good strategy to increase quality of life in the elderly; but genetic condition also plays an important role. The purpose of this study was to examine the association of the ACTN3 R577X polymorphism with physical fitness and muscle mass in physically active older women.

METHODS

A cross-sectional study was performed with two groups of older women who practiced physical exercise regularly. The first cohort comprised 164 women (age 69.7 ± 3.2 years) and the second cohort 131 women (age 78.5 ± 3.0 years). The main outcome measures were anthropometric measures with assessment of sarcopenia and sarcopenic obesity, self-reported physical activity EXERNET questionnaire (EEPAQ), evaluation of physical fitness (muscle strength and flexibility test), and ACTN3 genotyping.

RESULTS

Women above 75 years old with allele R presented a higher risk of experiencing sarcopenia compared to ACTNR XX homozygous women (odds ratio 0.356, 95% confidence interval 0.139-0.915, p = 0.026). Furthermore, statistically significant differences were found in the chair stand test (p = 0.04), as well as in the sit and reach test (p = 0.01), with better results for women below 75 years old with the ACTN3 XX genotype.

CONCLUSIONS

Sarcopenia and physical fitness show differences based on the ACTN3 R577X genotype in active older women.

Is Sitting Time Related with Physical Fitness in Spanishelderly Population? The EXERNET Multicenter Study

BACKGROUND

Older adults spend most of their waking hours performing sedentary activities. The influence of these lifestyle patterns on the physical fitness (PF) levels of this population has not yet been sufficiently investigated.

OBJECTIVE

The aim of the study was to examine whether sedentary behavior (SB) (h•d-1sitting) is associated with PF, and specifically to analyze whether sitting >4 h•d-1 is associated with higher risk of having lower levels of fitness in seniors.

DESIGN

EXERNET multi-center study.

PARTICIPANTS AND SETTINGS

A representative sample of 3136 non-institutionalized elderly (aged 72.2±5.3 years), from 6 Regions of Spain were included in the study.

MEASUREMENTS

PF was assessed using 8 different tests from the EXERNET battery. Lifestyle patterns were collected using a validated questionnaire. ANOVA was used to compare the groups according to the hours of sitting. Binary logistic regression was used to calculate the association between the SB and low levels of fitness.

RESULTS

For both genders, those who spent sitting >4 h•d-1 had lower levels of balance, agility, walking speed and aerobic endurance (p<0.001). Sedentary men also had less strength of lower extremities (p<0.05), whereas, sedentary women were less flexible in the lower extremities (p<0.001). More than 4 h•d-1 sitting was associated, in men, to higher odds for having low strength (lower extremities), agility, flexibility (lower extremities) and aerobic endurance (p<0.05); and in women, to higher risk of low balance, strength (lower and upper extremities), flexibility (lower extremities), agility, walking speed and aerobic endurance (p<0.05).

CONCLUSIONS

Seniors that sit >4 h•d-1 have lower levels of fitness and this behavior is related with an increased risk of having low levels of PF in this population.

Vigorous physical activity patterns affect bone growth during early puberty in boys

This study aims to analyze the impact of participation in vigorous physical activity as it can promote a healthy bone development. Adolescents who increased their participation in vigorous physical activity showed higher improvements in bone parameters compared to those who did not, which highlights the relevance of vigorous physical activity engagement.

INTRODUCTION

The main purpose of the study was to analyze the effects of different patterns of vigorous physical activity (VPA) on bone development.

METHODS

One-week accelerometry registers and dual-energy X-ray absorptiometry scans at the whole body, hip, and lumbar spine of 140 healthy male adolescents (11-13 years, at baseline) were performed twice with a 1-year interval between measurements. Four patterns of VPA evolution ("low-low," "low-high," "high-low," and "high-high") and three patterns of bone growth ("optimal," "mean," and "reduced") were defined according to the median participation in VPA and a cluster analysis of the longitudinal changes in BMC and BMD in all sites measured, respectively. Bone mineral parameters were adjusted for skeletal age and body weight prior to statistical comparison among groups.

RESULTS

Participants in the "low-high" group had greater adjusted BMD increases at both the femoral neck and lumbar spine when compared to the "low-low" group (estimated mean (95% CI) 0.066 (0.047-0.085) vs. 0.034 (0.021-0.047) g/cm² and 0.074 (0.054-0.093) vs. 0.049 (0.035-0.062) g/cm² respectively, both p < 0.05). Femoral neck BMD adjusted increase was also different between the "high-high" and the "high-low" groups (0.053 (0.041-0.066) vs. 0.030 (0.011-0.049) g/cm², p < 0.05). Additionally, a higher percentage of "optimal" growth was found in the "low-high" group than in the "low-low" and "high-low" categories (36.3, 12.5 and 13.6% respectively, p < 0.05).

CONCLUSIONS

Engaging in VPA as well as maintaining high levels of VPA during puberty is associated with greater gains in bone mass, which can have an impact in future bone health.

Do 6 months of whole-body vibration training improve lean mass and bone mass acquisition of adolescent swimmers?

Swimming has little effect on bone mass. Therefore, adolescent swimmers should complement their water training with a short and intense weight-bearing training, aiming to increase their bone acquisition. Forty swimmers performed a six-month whole-body vibration (WBV) training. WBV had no effect on adolescent swimmers' bone mass or lean mass.

PURPOSE

The aims of the present study were to evaluate the effects of a whole-body vibration (WBV) intervention on bone mineral density (BMD), bone mineral content (BMC) and lean mass (LM) in adolescent swimmers.

METHODS

Forty male and female adolescent swimmers (VIB; mean age 14.2 ± 1.9 years) completed the WBV protocol that consisted of 15 min of training 3 days per week during a 6-month period (ranging from 3.6 to 11.6 g), while 23 swimmers (SWI; mean age 15.0 ± 2.2 years) continued with their regular swimming training alone. VIB were divided into tertiles according to training compliance in order to evaluate if any dose-effect relation existed. BMD, BMC and LM were measured longitudinally by dual energy X-ray at the whole body, lumbar-spine and hip.

RESULTS

No group by time interactions and no differences in change percentage were found for BMD, BMC or LM in any of the measured variables. The mean change percentage of the subtotal body (whole body minus the head) for VIB and SWI, respectively, was 2.3 vs. 2.4% for BMD, 5.7 vs 5.7% for BMC and 7.3 vs. 8.0% for lean mass. Moreover, no indication for dose-response was observed.

CONCLUSIONS

The proposed WBV protocol had no effect on BMD, BMC and LM in adolescent swimmers. Other types of training should be used in this population to improve both bone and lean mass.

Swimming and bone: Is low bone mass due to hypogravity alone or does other physical activity influence it?

Swimming during adolescence has shown neutral or even negative effects on bone mass. Nevertheless, it is still unknown if these effects are due to swimming or to other factors, such as sedentary behaviors.

INTRODUCTION

Three objectives were described (1) to measure objective physical activity (PA) additional to swimming performed by adolescent swimmers (SWI) and compare it to that performed by normo-active controls (CG), (2) to describe the relationship between objectively measured PA and bone mass, and (3) to compare bone mass of swimmers that meet the World Health Organization PA guidelines (active) WHO and those that do not (inactive).

METHODS

A total of 71 SWI (33 females) and 41 CG (17 females) wore an accelerometer for at least 4 days. PA was expressed as the amount of time (minutes/day) in each intensity [sedentary/light/moderate or vigorous (VPA), and the sum of moderate and vigorous (MVPA)]. Using the cutoff points proposed by Vanhelst et al. SWI were classified as active or inactive according to whether they reached 60 min of weight-bearing MVPA per day or not. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry, and bone strength values were calculated with peripheral quantitative computed tomography. Differences in PA intensities were calculated between SWI and CG. The relation of VPA to bone mass was studied in the SWI.

RESULTS

Male-SWI spend less time in VPA and MVPA than male-GC, which partly explains the lower BMD values in SWI than CG.

CONCLUSION

Swimming may displace weight-bearing VPA with serious implications on bone health.

Change of direction ability test differentiates higher level and lower level soccer referees

This report examines the agility and level of acceleration capacity of Spanish soccer referees and investigates the possible differences between field referees of different categories. The speed test consisted of 3 maximum acceleration stretches of 15 metres. The change of direction ability (CODA) test used in this study was a modification of the Modified Agility Test (MAT). The study included a sample of 41 Spanish soccer field referees from the Navarre Committee of Soccer Referees divided into two groups: i) the higher level group (G1, n = 20): 2ndA, 2ndB and 3rd division referees from the Spanish National Soccer League (28.43 ± 1.39 years); and ii) the lower level group (G2, n = 21): Navarre Provincial League soccer referees (29.54 ± 1.87 years). Significant differences were found with respect to the CODA between G1 (5.72 ± 0.13 s) and G2 (6.06 ± 0.30 s), while no differences were encountered between groups in acceleration ability. No significant correlations were obtained in G1 between agility and the capacity to accelerate. Significant correlations were found between sprint and agility times in the G2 and in the total group. The results of this study showed that agility can be used as a discriminating factor for differentiating between national and regional field referees; however, no observable differences were found over the 5 and 15 m sprint tests.

Effect of whole-body vibration training on bone mass in adolescents with and without Down syndrome: a randomized controlled trial

Whole-body vibration training (WBV) attracts great interest as osteoporosis prevention strategy. Twenty-six adolescents with and without Down syndrome (DS) (13 DS; 12-18 years) performed 20 weeks of WBV. The results indicate that WBV seems to provoke a lesser response in adolescents with DS than in those without DS.

INTRODUCTION

This study aims to observe the differences between adolescents with and without DS in the effects of 20 weeks of WBV training, on bone mineral content (BMC) and density (BMD).

METHODS

Twenty-six adolescents (13 DS; 12-18 years) were measured with dual-energy X-ray absorptiometry before and after the intervention (3/week, 10 repetitions (30-60 s) and 1-min rest, frequency 25-30 Hz and peak-to-peak displacement of 2 mm (peak acceleration 2.5-3.6 g)). Both, an intention-to-treat (ITT) analysis designed to assess the effects on bone mass and a per-protocol analysis, designed to compare poor and high compliers, were performed.

RESULTS

The ITT analysis revealed significant increases in all BMC and BMD parameters (dz = 0.66 to 1.64; all p < 0.05) in the non-DS group, whilst DS group improved whole-body, subtotal (whole-body less head), upper limbs (ULIMBS), pelvis, lower limbs (LLIMBS) and spine BMC (dz = 0.75 to 1.76; all p < 0.05) and subtotal, pelvis, LLIMBS and spine BMD (dz = 0.73 to 1.28; all p < 0.05). Significantly greater increases were evident in the absolute and percent changes of the non-DS group over DS group (d = 0.88 to 3.85; all p < 0.05). ULIMBS BMD showed a tendency towards an interaction (f = 0.41 and p = 0.086) with higher increase for non-DS group. When a per-protocol analysis was considered, high-complier adolescents had 8.1 versus 5.3 % of gains in the spine BMC over poor-complier adolescents (d = 0.93; p < 0.05).

CONCLUSIONS

Twenty weeks of WBV training may improve BMC and BMD in clinically relevant skeletal sites in both groups. Nevertheless, this type of training seems to provoke a lesser response in adolescents with DS than in those without DS.

Effect of whole body vibration training on bone mineral density and bone quality in adolescents with Down syndrome: a randomized controlled trial

Adolescents with Down syndrome (DS) have poorer bone health than their peers without DS. Twenty-five adolescents with DS were randomly assigned to whole-body vibration training (WBV) or control groups. The results indicate that a 20-week WBV might be useful to improve subtotal bone mineral content and density in adolescents with DS.

INTRODUCTION

This study aims to determine the effects of 20 weeks of whole body vibration training (WBV) on bone mineral content (BMC), density (BMD), and structure variables in adolescents with Down syndrome (DS).

METHODS

This randomized controlled trial of 25 adolescents (12-18 years) with DS (8 females) generated 2 non-equal groups, WBV group (n = 11) and CON group (n = 14). Using an efficacy analysis, the primary outcomes were BMC and BMD by dual-energy X-ray absorptiometry and the secondary were bone structure variables by peripheral quantitative computed tomography. A synchronous vibration platform (PowerPlate®) was used (3/week, 10 repetitions (30-60 s) 1-min rest, frequency of 25-30 Hz, and peak-to-peak displacement of 2 mm (peak acceleration 2.5-3.6 g)).

RESULTS

WBV group improved whole body BMC 2.8%, 95% CI [3.5, 2.1], subtotal area, BMC, and BMD by 2.8, 4.8, and 2%, respectively, 95% confidence intervals (CIs) [3.4, 2.1], [6.5, 3.1], and [2.8, 1.1], respectively (all, p < 0.05), showing group by time interactions in BMC and BMD (both p < 0.05). Lumbar spine BMC and BMD also increased in the WBV group by 6.6 and 3.3% both p < 0.05, 95 % CIs [8.6, 4.7], and [4.9, 1.7], respectively. Regarding bone structure, WBV group showed improvements in tibial BMC at 4 % (2.9 %, 95 % CI [3.0, 2.8]) and in volumetric BMD (vBMD), cortical vBMD, and cortical thickness at 66% of the radius (by 7.0, 2.4, and 10.9%; 95% CIs [7.4, 6.7], [2.6, 2.3], and [12.4, 9.3], respectively) (all, p < 0.05).

CONCLUSIONS

A 20-week WBV, with this protocol, might be useful to improve subtotal BMC and BMD in adolescents with DS.

Validity of the V-cut Test for Young Basketball Players

The aim of the present study was to assess the reliability, usefulness, validity, age-related differences and responsiveness of a 25- m side-step cutting maneuver test (V-cut test). Fifty young male basketball players performed the V-cut test on 2 occasions separated by 5-7 days to assess test-retest reliability and determine a priori usefulness. Twenty subjects also completed both the L-Run and 505 test to analyze the possible relationships among these 3 tests. Furthermore, 33 players performed the V-cut test 4 times throughout the season to analyze responsiveness. Finally, 53 players (U-14 to U-20) were assessed in the V-cut test to examine the age-related differences. Reliability scores showed high intraclass correlation coefficient (ICC=0.90) and low coefficient of variation (CV=1.4%). The responsiveness of the V-cut test was good, as the typical short- (1.5-1.7%), mid- (1.6-3.1%) and long-term (3.3%) changes in V-cut performance were higher than the CV. Low (r=0.64; CL90%: 0.34; 0.82) to moderate (r=0.76; CL90%: 0.53; 0.88) relationships were found between the V-cut test with the 505 and L-Run test, respectively. Age-related differences analysis showed better V-cut test performance as age increased in adolescent basketball players. The V-cut test is reliable to assess change of direction ability (CODA) and it could be used to monitor CODA in adolescent basketball players.

Body Composition Evolution in Elite Football Referees; an Eleven-years Retrospective Study

Fitness, and specifically body composition of football referees requires attention in order to achieve the highest possible standards. The aim of the present study was to describe body composition of elite Spanish football referees over 11 years. Data from 2001 to 2012 pre-seasons were analyzed from a total of 470 referees of 1(st) and 2(nd) categories in Spanish male football (1C and 2C respectively). Body mass index (BMI), sum of 6 skinfolds (6SS) and percentage of body fat (%BF) were assessed. 2-independent samples Student's t-test between categories, and ANOVA tests with Bonferroni post-hoc analyses among seasons were applied. Overall, 1C referees were older than 2C in every season, and both 1C and 2C showed a decrease in 6SS, BMI and %BF throughout seasons (all p<0.05; from 82.5 to 62.9 mm, from 23.7 to 22.4 kg/m(2) and from 13.7 to 11.7%). No differences were observed between categories in any season. Since football referees at the highest levels need to have a low %BF for the intense matches nowadays, an improvement in their body composition profile has been observed in a highly competitive league as 'La Liga' in Spain over the last decade.

Combined effects of interaction between physical activity and nutrition on bone health in children and adolescents: a systematic review

CONTEXT

Osteoporosis is a major public health concern worldwide. Understanding the roles of diet and physical activity in ensuring adequate bone mass accrual during childhood and adolescence may help identify strategies to reduce the risk of osteoporotic fractures later in life.

OBJECTIVE

The present systematic review was conducted to provide an overview of the current knowledge of the combined effects of physical activity and diet on bone mass accrual in children and adolescents.

DATA SOURCES

Data were obtained via searches of the PubMed, EMBASE, SPORTDiscus, and ISI Web of Science databases.

STUDY SELECTION

Studies published in English and Spanish between 1887 and August 2013 were eligible for inclusion. Two investigators evaluated the studies against the inclusion and exclusion criteria. A total of 14 studies (7 cross-sectional and 7 experimental) were included in the review.

DATA EXTRACTION

The Pedro score and the Black and Down's checklist were used to evaluate the methodological quality of the experimental and the cross-sectional studies, respectively. Study characteristics were summarized in accordance with the review's PICO criteria.

DATA SYNTHESIS

Significant exercise-by-calcium interaction was detected at several different bone sites.

CONCLUSIONS

Although the results of cross-sectional studies were inconsistent, the results of randomized controlled trials showed that exercise has the potential to improve bone health under conditions of adequate calcium intake.

Higher levels of physical fitness are associated with a reduced risk of suffering sarcopenic obesity and better perceived health among the elderly: the EXERNET multi-center study

OBJECTIVE

To evaluate the associations between physical fitness levels, health related quality of life (HRQoL) and sarcopenic obesity (SO) and to analyze the usefulness of several physical fitness tests as a screening tool for detecting elderly people with an increased risk of suffering SO.

DESIGN

Cross-sectional analysis of a population-based sample.

SETTING

Non-institutionalized Spanish elderly participating in the EXERNET multi-centre study.

PARTICIPANTS

2747 elderly subjects aged 65 and older.

MEASUREMENTS

Body weight, height and body mass index were evaluated in each subject. Body composition was measured by bioelectrical impedance. Four SO groups were created based on percentage of body fat and relative muscle mass; 1) normal group, 2) sarcopenic group, 3) obesity group and 4) SO group. Physical fitness was evaluated using 8 tests (balance, lower and upper body strength, lower and upper body flexibility, agility, walking speed and aerobic capacity). Three tertiles were created for each test based on the calculated scores. HRQoL was assessed using the EuroQol visual analogue scale.

RESULTS

Participants with SO showed lower physical fitness levels compared with normal subjects. Better balance, agility, and aerobic capacity were associated to a lower risk of suffering SO in the fittest men (odds ratio < 0.30). In women, better balance, walking speed, and aerobic capacity were associated to a lower risk of suffering SO in the fittest women (odds ratio < 0.21) Superior perceived health was associated with better physical fitness performance.

CONCLUSIONS

Higher levels of physical fitness were associated with a reduced risk of suffering SO and better perceived health among elderly. SO elderly people have lower physical functional levels than healthy counterparts.

The effects of swimming training on bone tissue in adolescence

The aim was to analyze bone mineral content (BMC) and density (BMD) in regular swimming trained adolescents and the interaction that weigh-bearing sports may have on these values. Bone mass was evaluated by dual energy x-ray absorptiometry (DXA) and quantitative ultrasound (QUS) in 77 swimmers (34 females/43 males) and 52 normoactive controls (CG; 23 females/29 males) from 11 to 18 years. Swimmers who had performed or were performing other sports (OSP; 11 females/20 males) were compared with pure swimmers (PSW; 23 females/23 males). Both groups were compared with CG. Bone values were compared using analyses of covariance adjusting for height, calcium intake, subtotal lean (whole body lean minus head), and pubertal status. Male PSW showed lower BMD and BMC at several sites than male CG. However, for male OSP, only lumbar spine BMC was lower in OSP than male CG. Male PSW showed lower BMD and BMC when compared with male OSP. Female PSW showed higher arm BMD and lower leg BMC than female CG, while female OSP only presented lower leg BMC than female CG. Contrary to males, female-PSW presented higher BMD and BMC than female OSP. No differences in QUS values were found between swimmers and CG. To summarize, although more information is needed for females, it seems that for males, swimming is associated with lower BMC and BMD.

The nutritional status in adolescent Spanish cyclists

INTRODUCTION

Adolescence is an important period of nutritional vulnerability due to the increased dietary requirements.

OBJECTIVE

To describe the nutritional status of adolescent cyclist and a group of normoactive controls.

METHODS

The HELENA Dietary Assessment Tool was used to evaluate the nutritional intake of 20 adolescent cyclists and 17 controls. Total energy intake, resting energy expenditure (REE), total energy expenditure (TEE), macronutrients and several micronutrients were registered and compared with dietary guidelines.

RESULTS

REE was lower and TEE higher in cyclists than in controls (both P < 0.01). Significant differences were observed in phosphorus and vitamin B1 being higher in cyclists (P < 0.05). Most participants, both cyclist and controls, did not reach the diet requirements for macronutrients, vitamins and minerals.

CONCLUSION

Nutritional status of adolescent cyclists and controls seems not to fulfil the requirements in quantity and quality. Possible implications for actual and future health especially in athlete adolescents need further research.

Physical activity and cardiorespiratory fitness in adolescents with Down syndrome

AIMS

To determine if adolescents with and without Down syndrome (DS) accomplish the physical activity (PA) guidelines and to evaluate relationships between PA and cardiorespiratory variables.

METHODS

42 adolescents (27 with DS) participated in this study. PA was measured using accelerometers. Walking-graded treadmill protocol with a breath-by-breath gas analyzer was employed to assess cardiorespiratory fitness.

RESULTS

Adolescents with DS spent less time in sedentary PA, moderate PA (MPA), vigorous PA (VPA) and moderate to vigorous PA (MVPA) than those without DS. VO2peak was correlated with total minutes spent in light PA, MPA, VPA and MVPA in the control group (from r = 0.55 to r = 0.61, p < 0.05) and with MPA and MVPA in the DS group (from r = 0.38 to r = 0.41, p < 0.05).

CONCLUSION

Nor DS neither control groups achieved at least 60 minutes of MPA daily. Engaging more time in MPA was associated with greater cardiorespiratory fitness in adolescents with DS.

[Increased risk of obesity and central obesity in sedentary postmenopausal women]

AIMS

To establish the influence of a sedentary behavior (sit time) on body composition in elderly women from Aragón.

METHODS

A total of 457 women participated in the study. Hours of walking were used to define the active behavior (> 1 vs. < 1 h/day) and hours of sitting were used to establish the sedentary behavior (> 4 vs. < 4 h/day). Anthropometric evaluation was conducted following the ISAK recommendations. Fat mass was estimated through electrical bio-impedance. Differences between groups were analyzed by ANOVA and logistic regression analysis was used to study the association between active and sedentary behaviors with body composition.

RESULTS

The sedentary group had higher weight, BMI, waist circumference and fat mass than the non-sedentary group (all p < 0.05). In addition, those women who sat more than 4 h/day had 1.7, 2.7 and 1.7-fold higher odds ratio for having overweight, obesity and central obesity, respectively, regardless of the hours of walking (95% IC [1.006-2.739]; [1.518-4.491] y [1.154-2.565]). When activity and sedentary levels were studied together, active and sedentary women were 2.0 times more likely to be overweight (95% CI [0.995-3.961]), 4.4 to be obese (95% CI [2.101-9.264]) and 2.3 for having central obesity (95% CI [1.329-3.939]) than women with an active and non-sedentary behavior.

CONCLUSION

Being sitting more than 4 hours a day increases the risk of overweight, obesity and central obesity, regardless of the hours of walking in postmenopausal women.

Do calcium and vitamin D intake influence the effect of cycling on bone mass through adolescence?

INTRODUCTION

Cycling has been associated with decreased bone mass during adolescence. Calcium (Ca) and vitamin D (VitD) intake are associated to bone mass and may be important confounders when studying bone mass.

AIM

To clarify the effect that Ca and VitD may have on bone mass in adolescent cyclists.

METHODS

Bone mineral content (BMC) and density (BMD) of 39 male adolescents (20 cyclists) were measured. Ca and VitD intake were also registered. Different ANCOVA analyses were performed in order to evaluate the influence of Ca and VitD on BMC and BMD.

RESULTS

Cyclists showed lower values of BMC and BMD than controls at several sites and when adjusting by Ca, Wards triangle BMD appeared also to be lower in cyclists than controls.

CONCLUSION

Nutritional aspects might partially explain differences regarding bone mass in adolescent cyclists and should be taken into account in bone mass analysis as important confounders.

Do calcium and vitamin D intake influence the effect of cycling on bone mass through adolescence?

INTRODUCTION

Cycling has been associated with decreased bone mass during adolescence. Calcium (Ca) and vitamin D (VitD) intake are associated to bone mass and may be important confounders when studying bone mass.

AIM

To clarify the effect that Ca and VitD may have on bone mass in adolescent cyclists.

METHODS

Bone mineral content (BMC) and density (BMD) of 39 male adolescents (20 cyclists) were measured. Ca and VitD intake were also registered. Different ANCOVA analyses were performed in order to evaluate the influence of Ca and VitD on BMC and BMD.

RESULTS

Cyclists showed lower values of BMC and BMD than controls at several sites and when adjusting by Ca, Wards triangle BMD appeared also to be lower in cyclists than controls.

CONCLUSION

Nutritional aspects might partially explain differences regarding bone mass in adolescent cyclists and should be taken into account in bone mass analysis as important confounders.

Influence of hard vs. soft ground surfaces on bone accretion in prepubertal footballers

Information regarding osteogenic effects of physical activity performed on different playing surfaces is scarce. A total of 42 children (9.2±0.2 years, Tanner stages I-II) participated in this study. 14 were playing on artificial turf soft ground (SG), 14 on a natural non-grass hard ground (HG) and 14 were assigned to the sedentary control group (C). Whole body and hip scans (dual energy X-ray absorptiometry), anthropometric variables (weight and height) and physical fitness (VO2max) were determined in all participants. Bone mineral content (BMC) values were higher in the SG group compared to the C group at the legs (209.75±5.11 g vs. 187.42±5.14 g, respectively), pelvis (122.72±4.27 g vs. 98.58±4.29 g respectively) and whole-body level (1 126.1±22.81 g vs. 1 035.34±22.92 g, respectively). The hard ground (HG) group also showed higher values in the majority of BMC variables compared to the C group. Additionally, bone mineral density (BMD) was significantly higher at all sites of the hip in both active groups compared to control (P<0.05). No differences between HG and SG were found. In summary, similar bone mass accretion is obtained by prepubescent footballers independently of the surface on which they practice football.

Cortical and trabecular bone at the radius and tibia in male and female adolescents with Down syndrome: a peripheral quantitative computed tomography (pQCT) study

We aimed to describe the structure and strength of the tibia and radius of adolescents with Down syndrome. We observed that despite higher levels of volumetric bone mineral density in determined skeletal sites, they are at higher risk of developing osteoporotic fractures in the future due to their lower bone strength indexes.

INTRODUCTION

The aims of the study were to describe the cortical and trabecular volumetric bone mineral density (vBMD), bone mineral content (BMC), area, and bone strength in adolescents with Down syndrome (DS) and to compare them with adolescents without disabilities.

METHODS

Thirty adolescents (11 girls) with DS and 28 without disabilities (10 girls) participated in the study. Peripheral quantitative computed tomography measurements were taken at proximal and distal sites of the tibia and radius. Values of total, trabecular, and cortical BMC; vBMD; and area were obtained of each scan. Cortical thickness and endosteal and periosteal circumferences were also measured, and different bone strength indexes were calculated. Student's t tests were applied between groups.

RESULTS

The DS group showed greater vBMD at distal radius, BMC at proximal radius, and total and cortical vBMD at proximal tibia. The non-DS group showed higher total and trabecular area at the distal radius and total, cortical, and trabecular BMC and area at distal tibia. Higher values of periosteal and endosteal circumference and bone strength were also found in non-DS group.

CONCLUSIONS

From these results, it can be believed that even with higher vBMD in determined skeletal sites, adolescents with DS are at higher risk of suffering bone fractures due to an increased fragility by lower resistance to load bending or torsion.

[Aging and body composition: the sarcopenic obesity in Spain]

The increase in life expectancy occurred during the last decades has resulted in a growth of the elderly population, being estimated that a third of the Spanish population will be elderly (> 65 years) in the year 2050. Human aging involves many changes, such as a variation in body composition. Different factors work together leading to an increase in fat mass, decreased muscle mass and reduced bone mass among seniors. These characteristic changes among elderly people may lead to suffer several diseases such as obesity, sarcopenia and osteoporosis and may result in decreased quality of life, increased dependence and increased risk of mortality in this population. In the late 90's, "sarcopenic obesity" was a concept that emerged in order to define those people who simultaneously have an excess of body fat and a significant loss of muscle mass. Recently, for the first time in Spain (the elderly EXERNET multi-centre study), it has been shown that the prevalence of sarcopenic obesity in a representative sample of non-institutionalized seniors reaches values of 15%.

Effects of training on bone mass in older adults: a systematic review

It is widely recognized that the risk of fractures is closely related to the typical decline in bone mass during the ageing process in both women and men. Exercise has been reported as one of the best non-pharmacological ways to improve bone mass throughout life. However, not all exercise regimens have the same positive effects on bone mass, and the studies that have evaluated the role of exercise programmes on bone-related variables in elderly people have obtained inconclusive results. This systematic review aims to summarize and update present knowledge about the effects of different types of training programmes on bone mass in older adults and elderly people as a starting point for developing future interventions that maintain a healthy bone mass and higher quality of life in people throughout their lifetime. A literature search using MEDLINE and the Cochrane Central Register of Controlled Trials databases was conducted and bibliographies for studies discussing the effect of exercise interventions in older adults published up to August 2011 were examined. Inclusion criteria were met by 59 controlled trials, 7 meta-analyses and 8 reviews. The studies included in this review indicate that bone-related variables can be increased, or at least the common decline in bone mass during ageing attenuated, through following specific training programmes. Walking provides a modest increase in the loads on the skeleton above gravity and, therefore, this type of exercise has proved to be less effective in osteoporosis prevention. Strength exercise seems to be a powerful stimulus to improve and maintain bone mass during the ageing process. Multi-component exercise programmes of strength, aerobic, high impact and/or weight-bearing training, as well as whole-body vibration (WBV) alone or in combination with exercise, may help to increase or at least prevent decline in bone mass with ageing, especially in postmenopausal women. This review provides, therefore, an overview of intervention studies involving training and bone measurements among older adults, especially postmenopausal women. Some novelties are that WBV training is a promising alternative to prevent bone fractures and osteoporosis. Because this type of exercise under prescription is potentially safe, it may be considered as a low impact alternative to current methods combating bone deterioration. In other respects, the ability of peripheral quantitative computed tomography (pQCT) to assess bone strength and geometric properties may prove advantageous in evaluating the effects of training on bone health. As a result of changes in bone mass becoming evident by pQCT even when dual energy X-ray absortiometry (DXA) measurements were unremarkable, pQCT may provide new knowledge about the effects of exercise on bone that could not be elucidated by DXA. Future research is recommended including longest-term exercise training programmes, the addition of pQCT measurements to DXA scanners and more trials among men, including older participants.

Accuracy of prediction equations to assess percentage of body fat in children and adolescents with Down syndrome compared to air displacement plethysmography

To determine the accuracy of the published percentage body fat (%BF) prediction equations (Durnin et al., Johnston et al., Brook and Slaughter et al.) from skinfold thickness compared to air displacement plethysmography (ADP) in children and adolescents with Down syndrome (DS). Twenty-eight children and adolescents with DS (10-20 years old; 12 girls, 16 boys) participated in the study. Anthropometric measurements height, weight, and skinfolds biceps, triceps, subscapular and suprailiac were performed following ISAK recommendations. Total body density (TBD) was estimated using three equations and was also measured with ADP; while %BF was calculated from all densities using the Siri equation and from skinfolds using the Slaughter et al. equation. Finally, the agreement between methods was assessed by plotting the results in Bland-Altman graphs. The presence of heteroscedasticity was also examined. Despite the equation of Slaughter et al. had a large 95% limits of agreement, it was the only one without a significant inter-methods difference and without heteroscedasticity. The equation of Slaughter seems to be, from the studied, the most accurate for estimating %BF in children and adolescents with DS.

Bone mass in male and female children and adolescents with Down syndrome

SUMMARY

Children and adolescents with Down syndrome (DS) have lower levels of bone mass compared with youths without DS. Their sexual dimorphism in bone mass also differs from that observed in children and adolescents without Down syndrome.

INTRODUCTION

This study aimed to compare bone mass and sexual dimorphism in bone mass between male and female youths with DS and age- and sex-matched controls without DS.

METHODS

Bone mineral density (BMD), volumetric BMD, bone mineral apparent density (BMAD), BMD/height (BMDH), and total lean mass were measured or calculated from DXA. Thirty-two youths (15 females) with DS and 32 youths (13 females) without DS participated in the study.

RESULTS

ANOVA tests showed lower BMAD and BMDH in females with DS compared with females without DS. ANCOVA tests revealed lower BMD in the whole body of males and females as well as BMD in the hip region of the females with DS compared with their counterparts without DS. Within the group with DS, females had greater lumbar spine BMD than the males.

CONCLUSIONS

The low values of BMD and related parameters, together with the differences in the sexual dimorphism, indicate a non-standard bone development in this specific population of children and adolescents with DS.

Impact of methodological decisions on accelerometer outcome variables in young children

BACKGROUND

The impact of accelerometer-related methodological decisions relating to the assessment of physical activity and sedentary time has not been conclusively determined in young children.

OBJECTIVES

To determine the effects of epoch and cutoff points on the assessment of physical activity and sedentary time and to determine the accelerometer wear time required to achieve reliable accelerometer data in children.

DESIGN

Children were recruited from centres at Ghent, Glasgow, Gothenburg and Zaragoza.

METHODS

Physical activity was assessed for 1 week in 86 children (41 girls, 45 boys; mean age 7±2 years) by uniaxial accelerometry. The epoch was set at 15 s and reintegrated to 30 and 60 s. Time spent sedentary and in moderate and vigorous physical activity (MVPA) was assessed using a range of cutoff points. Number of days required to achieve 80% reliability was predicted using the Spearman-Brown Prophecy formula.

RESULTS

The Reilly cutoff points (<1100 counts per min (CPM)) indicated less sedentary time per day when comparing 15 vs 30 s and 15 vs 60 s epochs: 570±91 vs 579±93 min and 570±91 vs 579±94 min, respectively; P<0.05. Pate cutoff points (>420 counts per 15 s) reported more MVPA time per day compared with Sirard (890 counts per 15 s) and Puyau cutoff points (>3200 counts per min) using 15 s epoch: 78 (4-197) min (median (range) vs 18 (1-80) min and 24 (1-100) min, respectively; P<0.001. Compliance with guidelines of at least 60 min MVPA was 84, 78 and 73% for Pate cutoff points using 15, 30 and 60 s epochs, respectively, but 0% for Sirard and Puyau cutoff points across epochs. The number of days required to achieve 80% reliability for CPM, sedentary and MVPA time was 7.4-8.5 days.

CONCLUSION

Choice of epoch and cutoff point significantly influenced the classification of sedentary and MVPA time and observed compliance to the MVPA guidelines.

The IDEFICS validation study on field methods for assessing physical activity and body composition in children: design and data collection

OBJECTIVE

To describe the design, measurements and fieldwork of the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) physical activity and body composition validation study, and to determine the potential and limitations of the data obtained.

DESIGN

Multicentre validation study.

SUBJECTS

A total of 98 children from four different European countries (age: 4-10 years).

METHODS

An 8-day measurement protocol was carried out in all children using a collaborative protocol. Reference methods were the doubly labelled water method for physical activity, and a three- and a four-compartment model for body composition. Investigated field methods were accelerometers, a physical activity questionnaire and various anthropometric measurements.

RESULTS

For the validation of physical activity field methods, it was possible to gather data from 83 to 89 children, laying the basis for age- and sex-specific results. The validation of body composition field methods is possible in 64-80 children and allows sex-specific analyses but has only limited statistical power in the youngest age group (<6 years). The amount of activity energy expenditure (AEE) varied between centres, sexes and age groups, with boys and older children having higher estimates of AEE. After normalisation of AEE by body weight, most group-specific differences diminished, except for country-specific differences.

CONCLUSION

The IDEFICS validation study will allow age- and sex-specific investigation of questions pertaining to the validity of several field methods of body composition and physical activity, using established reference methods in four different European countries. From the participant analyses it can be concluded that the compliance for the investigated field methods was higher than that for the reference methods used in this validation study.

Health-related physical fitness in children and adolescents with Down syndrome and response to training

Physical fitness is related to health at all ages. Information about physical fitness in the Down syndrome (DS) population, however, is scarce, especially when we consider children and adolescents. A review of the current data available on this topic would be both timely and important as it would serve as a starting point to stimulate new research perspectives. The data we reviewed from the literature showed a general trend toward lower values of physical fitness parameters and worse body composition variables in children and adolescents with DS compared with the population without intellectual disability (ID) or even with the population with ID without DS. Notably, children and adolescents with DS have been described as less active or overprotected; however, these factors may not be the cause of their poor physical fitness. Many of the training programs carried out in children and adolescents with DS did not yield the desired responses, and the reasons are still unknown. The purpose of this review is to summarize the current available literature on health-related physical fitness in children and adolescents with DS, and the effect of training on these variables. From the literature available, it is clear that more data on this population are necessary.

Associations of muscular and cardiorespiratory fitness with total and central body fat in adolescents: the HELENA study

OBJECTIVE

to examine the association of healthrelated physical fitness with total and central body fat in adolescents.

PARTICIPANTS/METHODS

the present cross-sectional study comprises 363 Spanish adolescents (186 female participants) aged 12.5-17.5 years. We assessed fitness by the 20-m shuttle run test (cardiorespiratory fitness); the handgrip strength, the standing broad jump and the Abalakov tests (muscular strength); and the 4 × 10-m shuttle run test (speed-agility). Total body fat was measured by dual energy x-ray absorptiometry (DXA), BodPod and sum of six skinfolds, and central body fat was measured by DXA at three regions (R1, R2 and R3) and waist circumference.

RESULTS

the Abalakov, the standing broad jump, the 4 × 10-m shuttle run and the 20-m shuttle run tests were negatively associated with all markers of total and central body fat in men and women after controlling for age, pubertal status and objectively assessed physical activity (p<0.01). Handgrip strength test was positively associated with waist circumference (p<0.01).

CONCLUSIONS

lower body muscular strength and cardiorespiratory fitness are negatively and consistently associated with total and central body fat in adolescents, whereas levels of upper body muscular strength were superior in adolescents with higher levels of central body fat.

Physical repercussions of childhood-onset growth hormone (GH) deficiency and hGH treatment in adulthood

The aim of this study was to evaluate the physical condition of young adults with childhood-onset growth hormone deficiency (GHD) before and after 6 months of hGH therapy. Ten men and three women, aged 22.3 +/- 3.3 years, previously treated with hGH for 8.6 +/- 4.07 years at a dose of 0.5 IU/kg/week with a minimun of 2.5 years without treatment at the time of study, were studied. Nine patients presented isolated GHD and four patients had combined pituitary hormone deficiencies; they were treated with hGH at a dosage of 0.125 IU/kg/week for the first month and 0.25 IU/kg/week for the following 5 months. The tests performed were: exercise test, heart rate, rating of perceived exertion, blood lactate analysis, jump test and hand grip. Body composition was also analyzed using Holtain Body Analysis. Skinfold thickness was measured at four sites (triceps, biceps, subscapular and suprailiac). After 6 months of treatment a significant increase in lean body mass (42.0 +/- 7.72 to 46.2 +/- 8.01 kg, p = 0.004) and decrease in fat mass (19.6 +/- 10.01 to 16.1 +/- 10.79 kg, p = 0.01) were observed. The initial physical condition of these patients was lower than expected, and improved after treatment with an increase in maximum oxygen consumption from 2.0 +/- 1.2 to 2.33 +/- 0.68 l x min(-1) (p = 0.01). Maximum heart rate increased significantly from 189 +/- 14.8 to 193 +/- 11.7 beats x min(-1) (p = 0.03). No modifications were observed in anaerobic threshold (4 mmol x l(-1)). Only slight, non-significant increases were observed in jump and strength tests. We conclude that a) adults with childhood-onset growth hormone deficiency present a deficient physical condition and lower than expected for age and sex; b) this condition improves after 6 months of treatment, particularly in the aerobic aspect; c) changes observed in strength tests were discrete and of little significance; and d) the increase observed in lean body mass plays an important role in these changes. Further studies investigating GH action on maximum oxygen consumption are required, once its basic mechanism of action has been determined, either in the heart or peripheral factors.

Seasonal variation in fitness variables in professional soccer players

BACKGROUND

There have been many studies on soccer, but few evaluations of the physiological function of professional soccer players. The aim of this work was to evaluate seasonal variation--from September to February--in anthropometric and physiological variables in a Spanish professional soccer team (n=15).

METHODS

Anthropometric measurements were obtained following the standardised techniques adopted by the International Society for the Advancement of Kinanthropometry (ISAK). A maximal treadmill test with breath-by-breath gas analysis was carried out to evaluate the aerobic condition and a Jump test was used to measure muscle performance and strength in the lower limbs.

RESULTS

There were no significant variations in body mass, although a statistically significant decrease (p<0.05) in fat percentage and sum of six skinfolds was observed. The somatotype (Heath-Carter) was mesomorphic without any change observed throughout the season. The mean VO2max in the first test (65.5 ml x kg(-1) x min(-1)) had not changed by the second one (66.4 ml x kg(-1) x min(-1)). There were no significant differences in maximal heart rate (185 vs 185 beats x min(-1)) and treadmill speed at VO2max (16.1 vs 15.8 km x h(-1)). At the anaerobic threshold, there were significant differences (p<0.05) in speed (12.4 vs 13.1 km x h(-1)) and heart rate (164 vs 168 beats x min(-1)) as the season progressed. When the data were expressed as a percentage of maximal values obtained, we observed that the speed in the first test was 77 and 83% in the second test. For heart rate, values were 89 and 91%, and for oxygen uptake 77 and 79%. The Jump test did not show any significant change during the season.

CONCLUSIONS

We can conclude from these results that professional soccer players have good fitness from the beginning of the Spanish League--with a high VO2max--and the changes observed depend on the initial values.