RESUMO
ABSTRACT: Roth, R, Donath, L, Zahner, L, and Faude, O. Acute leg and trunk muscle fatigue differentially affect strength, sprint, agility, and balance in young adults. J Strength Cond Res 35(8): 2158-2164, 2021-How important leg or trunk muscles are for balance and sprint performance is still unexplored. Therefore, we separately fatigued the leg and trunk musculature and examined their contribution to strength, balance, sprint, and agility performance. Twenty-four healthy adults (12 women; age 22.9 [SD: 2.6] years; body mass 59 [10] kg; height 1.65 [0.09] m; and 12 men; age 22.7 [3.0] years; body mass 78 [9] kg; height 1.81 [0.06] m; at least 3 training sessions/week for at least 90 minutes) underwent a leg and a trunk fatigue procedure, each of 20-minute duration and a control condition at rest in a randomized order. Each condition was conducted individually on 3 separate days. Isokinetic leg and trunk strength, as well as static and dynamic balance, sprint, agility, and prone plank endurance, were assessed before and after each fatiguing protocol. Before assessment, a familiarization was conducted. Pairwise magnitude-based inference analyses showed likely relevant deterioration in leg (probability >87%; 0.36 < standardized mean differences [SMDs] < 0.92) and trunk (>88%, 0.28 < SMD < 0.74) fatigue procedures for all motor test parameters compared with the control condition, except for the 20-m sprint after the trunk fatigue procedure. Isokinetic strength testing revealed a large loss of strength in leg fatigue (particularly knee extension, 78%, SMD = 0.24) and trunk fatigue (trunk flexion, 100%, SMD = 1.36). Acute fatigue of leg and trunk muscles decreases performance in relevant measures of strength, balance, sprint, and agility. The impact of leg fatigue compared with trunk fatigue was larger in almost all measurements.
Assuntos
Perna (Membro) , Fadiga Muscular , Adulto , Teste de Esforço , Feminino , Humanos , Masculino , Força Muscular , Músculo Esquelético , Adulto JovemRESUMO
Markers of cardiovascular risk and cognitive performance were assessed in 347 children. In contrast with body mass index and blood pressure, only retinal microcirculation explained a unique proportion of variance in inhibitory control and information processing, when dependencies between markers of cardiovascular risk were accounted for.
Assuntos
Cognição , Fatores de Risco de Doenças Cardíacas , Vasos Retinianos/fisiologia , Pressão Sanguínea , Índice de Massa Corporal , Pré-Escolar , Estudos Transversais , Humanos , Microcirculação , SuíçaRESUMO
BACKGROUND: Advanced glycation end products (AGEs) accumulate with age and development of cardiovascular disease. Higher AGEs have been shown in children with diabetes but little is known about their association with lifestyle conditions in childhood. We hypothesized that BMI, blood pressure and cardiorespiratory fitness (CRF) are associated with subcutaneous AGEs formation in children. METHODS: In this cross-sectional study, 1075 children (aged 7.2 ± 0.4 years) were screened for subcutaneous AGEs (skin autofluorescence; SAF), body mass index (BMI), blood pressure (BP), and CRF using standardized procedures. Group comparisons were performed in clinical BP and BMI categories and tertiles of CRF. RESULTS: Children with higher physical fitness showed lower SAF (0.99(1.03;1.10)au) compared to children with low CRF (1.09(1.03;1.05)au, p < 0.001). An increase of one shuttle run stage was associated with a mean reduction in SAF of -0.033(CI: -0.042;-0.024)au, independent of BMI and BP (p < 0.001). BMI and BP were not independently associated with SAF-derived AGEs in this large cohort of primary school children. CONCLUSIONS: Low physical fitness but not BMI and BP were associated with higher levels of AGEs. Primary prevention programs in young children may need to focus on improving physical fitness in game settings in order to reduce the growing prevalence of metabolic disorders during childhood.
Assuntos
Aptidão Cardiorrespiratória , Produtos Finais de Glicação Avançada/metabolismo , Hipertensão/metabolismo , Doenças Metabólicas/metabolismo , Obesidade Infantil/metabolismo , Pele/metabolismo , Fatores Etários , Biomarcadores/metabolismo , Pressão Sanguínea , Índice de Massa Corporal , Criança , Estudos Transversais , Teste de Esforço , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/fisiopatologia , Medições Luminescentes , Masculino , Doenças Metabólicas/diagnóstico , Doenças Metabólicas/fisiopatologia , Obesidade Infantil/diagnóstico , Obesidade Infantil/fisiopatologia , Espectrometria de FluorescênciaRESUMO
The present study investigated whether psychosocial determinants mediate the effect of a telephone coaching intervention on physical activity levels. Two hundred eighty-eight adults were randomly assigned to a six-month telephone coaching intervention (n = 12 calls) or a control group receiving a single written recommendation. Seven psychosocial determinants as defined in the MoVo model as well as objective and self-reported physical activity levels were measured after 6 and 12 months. Participants also reported which taught intervention strategies (behavior change techniques) they perceived as most useful. Structural equation modeling was used to determine the mediating role of psychosocial determinants. Up to 227 participants with complete data on psychosocial determinants and physical activity were included in the mediation analyses. Compared to the control group, a greater increase in self-reported and objectively assessed physical activity levels was observed the coaching intervention group. The mediation analyses showed that the intervention had a positive effect on self-efficacy, outcome expectations and intention strength after 6 months and on action planning and barrier management after 6 and 12 months. Increases in objectively assessed physical activity after 6 months were mediated by increased barrier management. None of the other psychosocial determinants worked as mediating factors on self-reported or objectively assessed physical activity. The participants perceived 'action planning' and 'problem solving' as the most useful strategies to increase their physical activity levels. Further understanding of working mechanisms of remote physical activity promotion is needed.
Assuntos
Aconselhamento , Exercício Físico/psicologia , Telefone , Adulto , Terapia Comportamental , Feminino , Objetivos , Humanos , Intenção , Masculino , Tutoria , Autoeficácia , AutorrelatoRESUMO
BACKGROUND: Psychiatric disorders are associated with a high prevalence of cardiovascular disease. Regular exercise is known to reduce depressive symptoms and improve vascular function, in turn lowering cardiovascular risk. We aimed to investigate the effects of different exercise modalities on retinal vessel diameters as a microvascular biomarker and depression severity index in patients suffering from unipolar depression. METHODS: 23 patients (female: 19, male: 4, age: 36.7, Beck-Depression-Inventory-II (BDI-II) score: 30.7) were enrolled in this two-armed randomized controlled trial. Static vessel analysis was performed to obtain central retinal arteriolar (CRAE) and venular (CRVE) diameter equivalents and the arterio-venous diameter ratio (AVR). Maximal bicycle ergometer exercise testing yielded maximal fitness parameters. Patients were assigned to either high intensity low volume (HILV) or moderate continuous aerobic training (MCT). Both intervention groups trained three times a week during a 4-week intervention period. RESULTS: Moderate interaction effects were found for AVR (ɳp2â¯=â¯0.12) whereby HILV showed a larger increase in AVR (HILV: pre: 0.89 (0.04), post: 0.91 (0.04), SMDâ¯=â¯-0.50) compared to MCT (MCT: pre: 0.85 (0.06), post: 0.86 (0.05), SMDâ¯=â¯-0.18). Parallel group trials revealed a 67% possibly beneficial effect of HILV over MCT. Moderate interaction effects on depression severity reduction (ɳp2â¯=â¯0.06) were found, whereby the effect size was slightly larger in MCT. CONCLUSION: Both exercise interventions improved AVR as well as BDI-II. HILV may be more effective in improving cerebrovascular health. The exercise-induced effects on retinal vessel diameter changes were relatively small and the clinical relevance remains to be investigated in larger and longer-term exercise trials.
Assuntos
Arteríolas/fisiopatologia , Doenças Cardiovasculares/terapia , Depressão/terapia , Terapia por Exercício/métodos , Microcirculação , Vasos Retinianos/fisiopatologia , Vênulas/fisiopatologia , Adulto , Afeto , Arteríolas/diagnóstico por imagem , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/fisiopatologia , Depressão/diagnóstico , Depressão/fisiopatologia , Depressão/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vasos Retinianos/diagnóstico por imagem , Suíça , Fatores de Tempo , Resultado do Tratamento , Vênulas/diagnóstico por imagem , Adulto JovemRESUMO
PURPOSE: Incomplete maturation and aging-induced declines of the neuromuscular system affect postural control both in children and older adults and lead to high fall rates. Age-specific comparisons of the modulation of ankle muscle activation and behavioral center of pressure (COP) indices during upright stance have been rarely conducted. The objective of the present study was to quantify aging effects on a neuromuscular level. Thus, surface electromyography (SEMG) modulation and co-activity of ankle muscles during single-leg standing was compared in healthy children, young adults and seniors. METHODS: Postural steadiness (velocity and mean sway frequency of COP), relative muscle activation (SEMG modulation) and co-activation of two ankle muscles (tibialis anterior, TA; soleus, SO) were examined during single-leg stance in 19 children [age, 9.7 (SD 0.5) years], 30 adults [23.3 (1.5) years] and 29 seniors [62.7 (6.1) years]. RESULTS: Velocity of COP in medio-lateral and anterior-posterior directions, mean sway frequency in anterior-posterior direction, relative muscle activation (TA and SO) and co-activation revealed large age effects (P < 0.003, η p2 > 0.14). Post-hoc comparisons indicated higher COP velocities, anterior-posterior frequencies, relative SO activation and co-activation in children and seniors when compared with adults. Relative TA activation was higher in children and adults compared with seniors (P < 0.001). CONCLUSIONS: Increased postural sway in children and seniors seems to be counteracted with higher TA/SO co-activity and SO modulation. However, TA modulation is higher in children and adults, whereas seniors' TA modulation capacity is diminished. An aging-induced decline of TA motor units might account for deteriorations of TA modulation in seniors.
Assuntos
Envelhecimento/fisiologia , Tornozelo/fisiologia , Músculo Esquelético/fisiologia , Adulto , Idoso , Tornozelo/crescimento & desenvolvimento , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular , Músculo Esquelético/crescimento & desenvolvimento , Equilíbrio PosturalRESUMO
PURPOSE: To examine the effects of exercise-induced trunk fatigue on double poling performance, physiological responses and trunk strength in cross-country skiers. METHODS: Sixteen well-trained male cross-country skiers completed two identical pre- and post-performance tests, separated by either a 25-min trunk fatiguing exercise sequence or rest period in a randomized, controlled cross-over design. Performance tests consisted of a maximal trunk flexion and extension test, followed by a 3-min double poling (DP) test on a ski ergometer. RESULTS: Peak torque during isometric trunk flexion (- 66%, p < .001) and extension (- 7.4%, p = .03) decreased in the fatigue relative to the control condition. Mean external power output during DP decreased by 14% (p < .001) and could be attributed both to reduced work per cycle (- 9%, p = .019) and a reduced cycle rate (- 6%, p = .06). Coinciding physiological changes in peak oxygen uptake (- 6%, p < .001) and peak ventilation (- 7%, p < .001) could be observed. Skiers chose a more even-pacing strategy when fatigued, with the performance difference between fatigue and control condition being most prominent during the first 2 min of the post-test. CONCLUSIONS: In well-trained cross-country skiers, exercise-induced trunk fatigue led to a substantial decrease in DP performance, caused by both decreased work per cycle and cycle rate and accompanied by reduced aerobic power. Hence, improved fatigue resistance of the trunk may therefore be of importance for high-intensity DP in cross-country skiing.
Assuntos
Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Fadiga/fisiopatologia , Esqui/fisiologia , Adulto , Estudos Cross-Over , Teste de Esforço/métodos , Humanos , Masculino , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Consumo de Oxigênio/fisiologia , Resistência Física/fisiologia , Adulto JovemRESUMO
PURPOSE: In children, the pathways by which physical activity and fitness are associated with physical and psychological wellbeing are still not fully understood. The present study examines for the first time in young children whether high levels of cardiorespiratory fitness and physical activity moderate the relationship between severity of life events and health-related quality of life. METHODS: Three hundred and seventy-eight children (188 girls, 190 boys, M age = 7.27 years) participated in this cross-sectional study. Parental education, gender, age, severity of life events, health-related quality of life and physical activity were assessed via parental questionnaires. Cardiorespiratory fitness was assessed with the 20 m shuttle run test. Hierarchical regression analyses were used to test whether physical activity and fitness interacted with critical life events to explain health-related quality of life. RESULTS: When exposed to critical life events, children with higher fitness levels experienced higher levels of psychological wellbeing, relative to their less fit peers. On the other hand, children with higher fitness levels experienced higher physical wellbeing and more positive friendship relationships when severity of life events was low. A similar moderation effect was found for physical activity with overall quality of life as outcome. CONCLUSIONS: Recent stressful experiences alone were not sufficient to explain negative health outcomes in young children. Children with low cardiorespiratory fitness levels experienced lower psychological wellbeing when they were exposed to critical life events. More research is needed to find out whether similar findings emerge with objective physical activity measurements and when critical life events are assessed over longer periods of time.
Assuntos
Aptidão Cardiorrespiratória , Acontecimentos que Mudam a Vida , Aptidão Física/psicologia , Qualidade de Vida , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Análise de Regressão , SuíçaRESUMO
BACKGROUND: Aging is accompanied by a decline of executive function. Aerobic exercise training induces moderate improvements of cognitive domains (i.e., attention, processing, executive function, memory) in seniors. Most conclusive data are obtained from studies with dementia or cognitive impairment. Confident detection of exercise training effects requires adequate between-day reliability and low day-to-day variability obtained from acute studies, respectively. These absolute and relative reliability measures have not yet been examined for a single aerobic training session in seniors. METHODS: Twenty-two healthy and physically active seniors (age: 69 ± 3 y, BMI: 24.8 ± 2.2, VO2peak: 32 ± 6 mL/kg/bodyweight) were enrolled in this randomized controlled cross-over study. A repeated between-day comparison [i.e., day 1 (habituation) vs. day 2 & day 2 vs. day 3] of executive function testing (Eriksen-Flanker-Test, Stroop-Color-Test, Digit-Span, Five-Point-Test) before and after aerobic cycling exercise at 70% of the heart rate reserve [0.7 × (HRmax - HRrest)] was conducted. Reliability measures were calculated for pre, post and change scores. RESULTS: Large between-day differences between day 1 and 2 were found for reaction times (Flanker- and Stroop Color testing) and completed figures (Five-Point test) at pre and post testing (0.002 < p < 0.05, 0.16 < ɳp2 < 0.38). These differences notably declined when comparing day 2 and 3. Absolute between days variability (CoV) dropped from 10 to 5% when comparing day 2 vs. day 3 instead of day 1 vs. day 2. Also ICC ranges increased from day 1 vs. day 2 (0.65 < ICC < 0.87) to day 2 vs. day 3 (0.40 < ICC < 0.93). Interestingly, reliability measures for pre-post change scores were low (0.02 < ICC < 0.71). These data did not improve when comparing day 2 with day 3. During inhibition tests, reaction times showed excellent reliability values compared to the poor to fair reliability of accuracy. CONCLUSION: Notable habituation to the whole testing procedure should be considered as it increased the reliability of different executive function tests. Change scores of executive function after acute aerobic exercise cannot be detected reliably. Large intra- and inter-individual of responses to acute aerobic exercise in seniors can be presumed.
Assuntos
Cognição/fisiologia , Função Executiva/fisiologia , Exercício Físico , Idoso , Estudos Cross-Over , Exercício Físico/fisiologia , Exercício Físico/psicologia , Teste de Esforço/métodos , Feminino , Frequência Cardíaca/fisiologia , Humanos , Individualidade , Masculino , Testes Neuropsicológicos , Tempo de Reação/fisiologia , Reprodutibilidade dos TestesRESUMO
OBJECTIVES: Whether occupational physical activity (PA) will be assessed via questionnaires or accelerometry depends on available resources. Although self-reported data collection seems feasible and inexpensive, obtained information could be biased by demographic determinants. Thus, we aimed at comparing self-reported and objectively measured occupational sitting, standing, and walking times adjusted for socio-demographic variables. METHODS: Thirty-eight office employees (eight males, 30 females, age 40.8 ± 11.4 years, BMI 23.9 ± 4.2 kg/m(2)) supplied with height-adjustable working desks were asked to report sitting, standing, and walking times using the Occupational Sitting and Physical Activity Questionnaire during one working week. The ActiGraph wGT3X-BT was used to objectively measure occupational PA during the same week. Subjectively and objectively measured data were compared computing the intra-class correlation coefficients, paired t tests and Bland-Altman plots. Furthermore, repeated-measurement ANOVAs for measurement (subjective vs. objective) and socio-demographic variables were calculated. RESULTS: Self-reported data yielded a significant underestimation of standing time (13.3 vs. 17.9%) and an overestimation of walking time (12.7 vs. 5.0%). Significant interaction effects of age and measurement of standing time (F = 6.0, p = .02, ηp(2) = .14) and BMI group and measurement of walking time were found (F = 3.7, p = .04, ηp(2) = .17). Older employees (>39 years) underestimated their standing time, while underweight workers (BMI < 20 kg/m(2)) overestimated their walking time. CONCLUSIONS: Self-reported PA data differ from objective data. Demographic variables (age, BMI) affect the amount of self-reported misjudging of PA. In order to improve the validity of self-reported data, a correction formula for the economic assessment of PA by subjective measures is needed, considering age and BMI.
Assuntos
Acelerometria , Postura , Autorrelato , Caminhada , Adulto , Fatores Etários , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Local de TrabalhoRESUMO
Socio-economic status during childhood has been shown to be a strong predictor of adult health outcome. Therefore, we examined associations of parental educational level, household income and migrant background with physical fitness, spinal flexibility, spinal posture as well as retinal vessel diameters in children of an urban Swiss region. A total of 358 first graders of the Swiss canton Basel-Stadt (age: 7.3, SD: 0.4) were examined. Physical fitness (20 m shuttle run test, 20 m sprint, jumping sidewards and balancing backwards), spinal flexibility and spinal posture (MediMouse®, Idiag, Fehraltdorf, Switzerland) and retinal microcirculation (Static Retinal Vessel Analyzer, Imedos Systems UG, Jena, Germany) were assessed. Parental education, household income, migrant background and activity behaviour were evaluated with a questionnaire. Parental education was associated with child aerobic fitness (P = 0.03) and screen time (P < 0.001). Household income was associated with jumping sidewards (P = 0.009), balancing backwards (P = 0.03) and sports club participation (P = 0.02). Migrant background was associated with BMI (P = 0.001), body fat (P = 0.03), aerobic fitness (P = 0.007), time spent playing outdoors (P < 0.001) and screen time (P < 0.001). For spinal flexibility and retinal vessel diameter, no associations were found (0.06 < P < 0.8). Low parental education, low household income and a migrant background are associated with poor physical fitness, higher BMI and body fat percentage and low-activity behaviour.
Assuntos
Aptidão Física , Postura , Vasos Retinianos/anatomia & histologia , Fatores Socioeconômicos , Coluna Vertebral/fisiologia , Índice de Massa Corporal , Criança , Escolaridade , Emigrantes e Imigrantes , Exercício Físico , Teste de Esforço , Feminino , Humanos , Masculino , Inquéritos e Questionários , SuíçaRESUMO
For performance and injury prevention in sport, core strength and endurance are focused prerequisites. Therefore we evaluated characteristics of trunk muscle activation and performance during strength-endurance related trunk field tests. Strength-endurance ability, as total time to failure, and activation of trunk muscles was measured in 39 football players of the highest German female football league (Bundesliga) (N = 18, age: 20.7 y [SD 4.4]) and the highest national male under-19 league (N = 21, age: 17.9 y [0.7]) in prone plank, side plank, and dorsal position. Maximal isometric force was assessed during trunk extension and flexion, rotation, and lateral flexion to normalize EMG and to compare with the results of strength-endurance tests. For all positions of endurance strength tests, a continuous increase in normalized EMG activation was observed (P < .001). Muscle activation of the rectus abdominis and external oblique in prone plank position exceeded the maximal voluntary isometric contraction activation, with a significantly higher activation in females (P = .02). We conclude, that in the applied strength-endurance testing, the activation of trunk muscles was high, especially in females. As high trunk muscle activation can infer fatigue, limb strength can limit performance in prone and side plank position, particularly during high trunk muscle activation.
Assuntos
Desempenho Atlético/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Futebol/fisiologia , Tronco/fisiologia , Adolescente , Estudos Transversais , Eletromiografia , Feminino , Alemanha , Humanos , Contração Isométrica/fisiologia , Masculino , Resistência Física/fisiologiaRESUMO
BACKGROUND: Balance and strength training can reduce seniors' fall risk up to 50%. Available evidence suggests that acute bouts of neuromuscular and endurance exercise deteriorate postural control. High-intensity endurance training has been successfully applied in different populations. Thus, it seemed valuable to examine the acute effects of high-intensity interval training (HIIT) on neuromuscular performance in seniors and young adults. OBJECTIVE: The acute impact of a HIIT session on balance performance and muscle activity after exercise cessation and during post-exercise recovery was examined in young and old adults. We intended to investigate whether a transient exercise-induced fall-risk may occur in both groups. METHODS: 20 healthy seniors (age 70 (SD 4) years) and young adults (age 27 (SD 3) years) were examined on 3 days. After exhaustive ramp-like treadmill testing in order to determine maximal heart rate (HRmax) on the first day, either a 4 × 4 min HIIT at 90% of HRmax or a control condition (CON) was randomly performed on the second and third day, respectively. Balance performance (postural sway) was assessed during single limb stance with open eyes (SLEO) and double limb stance with closed eyes (DLEC). EMG was recorded for the soleus (SOL), anterior tibialis (TIB), gastrocnemius (GM) and peroneus longus (PL) muscles at the dominant leg. All measures were collected before, immediately as well as 10, 30 and 45 min after HIIT and CON, respectively. RESULTS: Compared to CON, HIIT induced significant increases of postural sway immediately after exercise cessation during SLEO in both groups (adults: p < 0.001, Δ = +25% sway; seniors: p = 0.007, Δ = +15% sway). Increased sway during DLEC was only found for seniors immediately and 10 min after HIIT (post: p = 0.003, Δ = +14% sway, 10 min post: p = 0.004, Δ = +18% sway). Muscle activity was increased during SLEO for TIB until 10 min post in seniors (0.008 < p < 0.03) and immediately after HIIT in adults (p < 0.001). CONCLUSION: HIIT training may cause an acute 'open-fall-window' with a transient impairment of balance performance for at least 10 min after exercise cessation in both groups. Occluded vision in seniors seems to prolong this period up to 30 min. Thus, the advantage of HIIT with regard to time efficiency seems debatable when considering transient HIIT-induced impairments of neuromuscular function.
Assuntos
Acidentes por Quedas , Exercício Físico/fisiologia , Músculo Esquelético/fisiologia , Equilíbrio Postural/fisiologia , Adulto , Idoso , Estudos Cross-Over , Eletromiografia , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Risco , Adulto JovemRESUMO
BACKGROUND: Available evidence suggests that young adults and seniors use different strategies to adjust for increasing body sway during quiet standing. Altered antagonist muscle co-activation and different ankle muscle coordination patterns may account for this finding. Consequently, we aimed at addressing whether aging leads to changes in neuromuscular coordination patterns as well as co-activation during quiet stance. We additionally investigated whether a bout of high intensity interval training additionally alters these patterns. METHODS: Twenty healthy seniors (age: 70 ± 4 y) and twenty young adults (age: 27 ± 3 y) were enrolled in the present study. In between the testing procedures, four consecutive high-intensity intervals of 4 min duration at a target exercise intensity of 90 to 95% HRmax were completed on a treadmill. The total center of pressure (COP) path length displacement served as standing balance performance outcome. In order to assess ankle muscle coordination patterns, amplitude ratios (AR) were calculated for each muscle (e.g. tibialis anterior (TA) [%] = (TA × 100)/(gastrocnemius medialis (GM) + soleus (SOL) + peroneus longus (PL) + TA). The co-activation was calculated for the SOL and TA muscles computing the co-activation index (CAI = 2 × TA/TA + SOL). RESULTS: Seniors showed an inverted ankle muscle coordination pattern during single limb stance with eyes open (SLEO), compared to young adults (rest: GM, S: 15 ± 8% vs Y: 24 ± 9%; p = 0.03; SOL, S: 27 ± 14% vs Y: 37 ± 18%; p = 0.009; TA, S: 31 ± 13% vs Y: 13 ± 7%; p = 0.003). These patterns did not change after a high-intensity training session. A moderate correlation between amplitude ratios of the TA-contribution and postural sway was observed for seniors during SLEO (r = 0.61). Ankle co-activation was twofold elevated in seniors compared to young adults during SLEO (p < 0.001). These findings were also not affected by high intensity training. CONCLUSION: Increased ankle co-activation in the anterior-posterior plane and inverted ankle muscle coordination pattern merely occurred during single-leg stance. Seniors with decreased postural control showed higher TA contributions during SLEO. These neuromuscular changes are not affected by acute intermittent high intensity aerobic exercise.
Assuntos
Acidentes por Quedas/prevenção & controle , Articulação do Tornozelo , Contração Muscular/fisiologia , Músculo Esquelético , Equilíbrio Postural/fisiologia , Adulto , Idoso , Envelhecimento/fisiologia , Tornozelo , Articulação do Tornozelo/fisiologia , Articulação do Tornozelo/fisiopatologia , Eletromiografia/métodos , Exercício Físico/fisiologia , Teste de Esforço/métodos , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia , Músculo Esquelético/fisiopatologia , Postura/fisiologia , Fatores de TempoRESUMO
OBJECTIVE: Many accidents at construction sites are due to falls. An exercise-based workplace intervention may improve intrinsic fall risk factors. In this pilot study, we aimed at evaluating the effects of neuromuscular exercise on static and functional balance performance as well as on lower limb explosive power in construction workers. METHODS: Healthy middle-aged construction workers were non-randomly assigned to an intervention [N = 20, age = 40.3 (SD 8.3) years] or a control group [N = 20, age = 41.8 (9.9) years]. The intervention group performed static and dynamic balance and strength exercises (13 weeks, 15 min each day). Before and after the intervention and after an 8-week follow-up, unilateral postural sway, backward balancing (on 3- and 4.5-cm-wide beams) as well as vertical jump height were assessed. RESULTS: We observed a group × time interaction for postural sway (p = 0.002) with a reduction in the intervention group and no relevant change in the control group. Similarly, the number of successful steps while walking backwards on the 3-cm beam increased only in the intervention group (p = 0.047). These effects were likely to most likely practically beneficial from pretest to posttest and to follow-up test for postural sway (+12%, standardized mean difference (SMD) = 0.65 and 17%, SMD = 0.92) and backward balancing on the 3-cm beam (+58%, SMD = 0.59 and 37%, SMD = 0.40). CONCLUSIONS: Fifteen minutes of neuromuscular training each day can improve balance performance in construction workers and, thus, may contribute to a decreased fall risk.
Assuntos
Indústria da Construção , Exercícios de Alongamento Muscular/métodos , Traumatismos Ocupacionais/prevenção & controle , Treinamento Resistido/métodos , Acidentes por Quedas/prevenção & controle , Adulto , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Projetos Piloto , Equilíbrio Postural , Fatores de Tempo , CaminhadaRESUMO
Physical inactivity is one the biggest Public Health problems of the 21th century. Regular physical activity and sports can contribute to a reduction of overall mortality and morbidity and, thus, can have a considerable health impact for individuals as well as for the society as a whole. The beneficial health effects of exercise are convincingly evaluated yet and there is further evidence that physical activity can result in improvements in specific cardiorespiratory and metabolic diseases similar to pharmacological treatments. It is the aim of this review article to outline evidence-based guidelines for exercise to improve physical fitness and health in primary prevention in healthy adults. Based on the current scientific evidence a dose-response-relationship between physical activity and health markers as well as physical fitness is likely. Health-oriented exercise training should allow for an exercise-induced energy expenditure of at least 1000 kcal per week. This should be approached by an appropriate combination of exercises targeting on an improvement in cardiorespiratory and metabolic functioning as well as muscular fitness. It is recommended to supplement such a training regimen by appropriate amounts of functional and flexibility exercises. Usually, sports targeting on these particular fitness areas are recommended, for instance, typical endurance sports like cycling, jogging, (Nordic) walking or swimming for the cardiorespiratory and metabolic domains and strength training for muscular fitness. In recent years, scientific studies have evaluated potentially more attractive sports like football, dancing and Tai Chi and reported promising results. Such sports may contribute to an increased long-term compliance to health-oriented exercise programmes. Although regular physical activity is associated with considerable health benefits, risks and side effects should be taken into account. The most frequent side effects are injuries, and the most severe are fatal cardiac events. Preventive measures should be applied to reduce the risk of these side effects. Health-oriented exercise guidelines should incorporate individual preferences and training responses to support a permanent adaptation towards a sportive life style.
Assuntos
Doença Crônica/prevenção & controle , Exercício Físico , Recreação , Esportes , Traumatismos em Atletas/etiologia , Traumatismos em Atletas/prevenção & controle , Metabolismo Energético , Parada Cardíaca/etiologia , Parada Cardíaca/prevenção & controle , Humanos , Aptidão Física , Fatores de Risco , SuíçaRESUMO
The proportion of older people in western societies rapidly increases. Aging-induced disease conditions accompanied with declines in cardiocirculatory and neuromuscular performance constitute a major individual and economic health burden. Besides decreasing vascular and cardiac function during the process of aging, a loss of skeletal muscle mass, muscle structure and function seem to mainly account for decreasing maximal strength, strength development and strength endurance. These findings adversely interfer with static and dynamic postural control and may lead to an increased risk of falling with impairments of autonomy and quality of life. Traditional strength training recommendations basing on health-related exercise prescriptions for elderly people have been proven to counteract or at least attenuate aging-induced declines of neuromuscular muscular function. Multimodal and combined strength and balance training deliver additional improvements of neuromuscular capacity. Recent evidence additionally underpin the need of trunk muscle training and claimed for regimes considering explosive and high-velocity strength training in seniors. High quality RCTs revealed notable strength training effects on mobility, autonomy, quality of life and the reduction of the risk of falling (up to 50%). Available evidence also indicates that various strength training regimes elicit preventive and therapeutic effects on osteoporosis, diabetes type 2 and other chronic diseases, with effect sizes comparable to medication intake. Thus, health care providers, health insurances, Employers' Liability Insurance Associations and politicians should promote infrastructural developments that enable feasible and cost-effective access to health-related fitness centers or other sport facilities (e. g. sport clubs). These environmental requirements should be embedded in multi-centric education programs and campaigns that might enable regularly conducted strength and endurance training perceived as beneficial and valuable from an individual health care perspective.
Assuntos
Doença Crônica/prevenção & controle , Idoso Fragilizado , Força Muscular/fisiologia , Dinâmica Populacional , Treinamento Resistido , Idoso , Humanos , Fatores de Risco , SuíçaRESUMO
This study examined transfer effects of fall training on fear of falling (Falls Efficacy Scale-International [FES-I]), balance performance, and spatiotemporal gait characteristics in older adults. Eighteen community-dwelling older adults (ages 65-85) were randomly assigned to an intervention or control group. The intervention group completed 12 training sessions (60 min, 6 weeks). During pre- and posttesting, we measured FES-I, balance performance (double limb, closed eyes; single limb, open eyes; double limb, open eyes with motor-interfered task), and gait parameters (e.g., velocity; cadence; stride time, stride width, and stride length; variability of stride time and stride length) under single- and motor-interfered tasks. Dual tasks were applied to appraise improvements of cognitive processing during balance and gait. FES-I (p = .33) and postural sway did not significantly change (0.36 < p < .79). Trends toward significant interaction effects were found for step width during normal walking and stride length variability during the motor dual task (p = .05, ηp 2 = .22). Fall training did not sufficiently improve fear of falling, balance, or gait performance under single- or dual-task conditions in healthy older adults.
Assuntos
Acidentes por Quedas/prevenção & controle , Marcha/fisiologia , Equilíbrio Postural/fisiologia , Transferência de Experiência/fisiologia , Adaptação Fisiológica , Idoso , Idoso de 80 Anos ou mais , Cognição/fisiologia , Feminino , Habitação para Idosos , Humanos , Masculino , Artes Marciais/fisiologia , Artes Marciais/psicologia , Projetos Piloto , Valores de Referência , Inquéritos e Questionários , CaminhadaRESUMO
Over 300 million individuals worldwide suffer from major depressive disorder (MDD). Individuals with MDD are less physically active than healthy people which results in lower cardiorespiratory fitness (CRF) and less favorable perceived fitness compared with healthy controls. Additionally, individuals with MDD may show autonomic system dysfunction. The purpose of the present study was to evaluate the CRF, perceived fitness and autonomic function in in-patients with MDD of different severity compared with healthy controls. We used data from 212 in-patients (age: 40.7 ± 12.6 y, 53% female) with MDD and from 141 healthy controls (age: 36.7 ± 12.7 y, 58% female). We assessed CRF with the Åstrand-Rhyming test, self-reported perceived fitness and autonomic function by heart rate variability (HRV). In specific, we used resting heart rate, time- and frequency-based parameters for HRV. In-patients completed the Beck Depression Inventory-II (BDI-II) to self-assess the subjectively rated severity of depression. Based on these scores, participants were grouped into mild, moderate and severe MDD. The main finding was an inverse association between depression severity and CRF as well as perceived fitness compared with healthy controls. Resting heart rate was elevated with increasing depression severity. The time-based but not the frequency-based autonomic function parameters showed an inverse association with depression severity. The pattern of results suggests that among in-patients with major depressive disorder, those with particularly high self-assessed severity scores show a lower CRF, less favorable perceived fitness and partial autonomic dysfunction compared to healthy controls. To counteract these conditions, physical activity interventions may be effective.
Assuntos
Sistema Nervoso Autônomo , Aptidão Cardiorrespiratória , Transtorno Depressivo Maior , Frequência Cardíaca , Índice de Gravidade de Doença , Humanos , Feminino , Masculino , Adulto , Aptidão Cardiorrespiratória/fisiologia , Transtorno Depressivo Maior/fisiopatologia , Frequência Cardíaca/fisiologia , Pessoa de Meia-Idade , Sistema Nervoso Autônomo/fisiopatologia , Escalas de Graduação PsiquiátricaRESUMO
Major depressive disorder (MDD) is an increasingly common psychiatric illness associated with a high risk of insufficient physical activity, which in turn is associated with negative mental and physical health outcomes. Theory-based, individually tailored, in-person and remote physical activity counseling has the potential to increase physical activity levels in various populations. Given this, the present study investigated the effect of such a physical activity intervention on the physical activity behavior of in-patients with MDD. This was a multi-center, two-arm randomized controlled trial including initially insufficiently physically active adult in-patients with MDD from four study sites in Switzerland. The sample consisted of 220 participants (Mage = 41 ± 12.6 years, 52% women), 113 of whom were randomized to the intervention group and 107 to the control group. The main outcome, moderate-to-vigorous physical activity (MVPA), was assessed at three time points via hip-worn accelerometer. According to accelerometer measures, there was no significant difference in minutes spent in MVPA over a 12-month intervention period when comparing the intervention with the control group (ß = -1.02, 95% CI = -10.68 to 8.64). Higher baseline physical activity significantly predicted physical activity at post and follow-up. This study showed that it is feasible to deliver an individually tailored, theory-based physical activity counseling intervention to in-patients with MDD, however yielding no significant effects on accelerometer-based MVPA levels. Further efforts are warranted to identify efficacious approaches.Trial registration: ISRCTN, ISRCTN10469580, registered on 3rd September 2018, https://www.isrctn.com/ISRCTN10469580 .