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1.
Sports Med ; 2024 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-38762832

RESUMO

Hypertension is recognised as a leading attributable risk factor for cardiovascular disease and premature mortality. Global initiatives towards the prevention and treatment of arterial hypertension are centred around non-pharmacological lifestyle modification. Exercise recommendations differ between professional and scientific organisations, but are generally unanimous on the primary role of traditional aerobic and dynamic resistance exercise. In recent years, isometric exercise training (IET) has emerged as an effective novel exercise intervention with consistent evidence of reductions in blood pressure (BP) superior to that reported from traditional guideline-recommended exercise modes. Despite a wealth of emerging new data and endorsement by select governing bodies, IET remains underutilised and is not widely prescribed in clinical practice. This expert-informed review critically examines the role of IET as a potential adjuvant tool in the future clinical management of BP. We explore the efficacy, prescription protocols, evidence quality and certainty, acute cardiovascular stimulus, and physiological mechanisms underpinning its anti-hypertensive effects. We end the review with take-home suggestions regarding the direction of future IET research.

2.
Biol Sport ; 41(2): 73-82, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38524824

RESUMO

This study explored physical match demands across different playing positions during transitional play, to inform the need for position-specific training interventions. Data was collected using 10 Hz GPS units from 10 competitive matches including 23 elite soccer players of the 1st Polish Division (Ekstraklasa) in season 2020-21. A total of 4249 positional observations were made; center backs (n = 884), full backs (n = 972), central defensive midfielders (n = 236), central attacking midfielders (n = 270), central midfielders (n = 578), wingers (n = 778), and attackers (n = 531). Match data reflected distances covered per minute (m · min-1): total distance (TD), high-speed running distance (HSRD, > 19.8 km · h-1), sprint distance (SD, > 25.2 km · h-1), and the frequency of high-intensity accelerations and decelerations (A+D, > 3 m · s-2; n · min-1). Total absolute sprint distance (SD, > 25.2 km · h-1) and total relative sprint distance (Rel B5) were also quantified. A univariate analysis of variance revealed position-specific differences. Significant effects of position were found for all analysed metrics during transitional play (large ESs; p <.001). Central attacking midfielders displayed higher TD (m · min-1), fullbacks covered highest SD (m · min-1) and wingers achieved the highest A+D (n · min-1) (p ≤ 0.05). Centre backs displayed the lowest physical outputs when compared to all other positions, except in A+D (n · min-1) during defensive transitions (p ≤ 0.05). Attackers displayed the highest physical metrics during high pressure activities (p ≤ 0.05). Coaches should carefully consider positional transitional demands to better inform training design. With specific attention paid to drills that replicate game play.

3.
Res Q Exerc Sport ; : 1-13, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38100605

RESUMO

Aim: To understand mean (WCSmean) and peak (WCSpeak) worst case scenarios within training and game play in male professional soccer. Methods: Thirty-one (n = 31) first team players were monitored across 37 matches and 14 MD-3 sessions. Playing status was distinguished, football drills analyzed, and performance explored in long-period: >6 days, moderate-period: 5-6 days, and congested-period: ≤4 days. Relative total distance (TD), high-speed running distance (HSRD, >19.8 km·h-1), sprint distance (SD, >25.2 km·h-1), accelerations/decelerations (A+D, >3 m·s-2), accelerations (Acc, >3 m·s-2), and decelerations (Dec, >-3 m·s-2) were measured as well as Maximum acceleration (Max Acc; m·s-2) and deceleration (Max Dec; m·s-2). Results: Analysis of variance found differences between matches and training in WCSmean for TD, HSRD, SD, and Max Dec in all positions (p < .001; partial η2 > .275). Fullbacks displayed differences between match and training in Max Acc (moderate ESs; p < .001), while center backs and central midfielders in Max Dec (large ESs; p > .05). Main effects of playing status were discovered for all metrics except Max Dec (p < .001; partial η2 > .124). Analysis showed differences between long- and congested-period for A+D and Dec (large ESs; p ≤ .05). Conclusions: Findings provide more insights into short peak intensity demands of soccer showing that the maximum high velocity action of acceleration and deceleration is not being replicated in training. Nonstarters lack maximum intensity exposure in matches (WCSpeak) increasing the gap between training and competition even higher during congested fixture periods.

4.
J Strength Cond Res ; 37(10): 2032-2037, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37129589

RESUMO

ABSTRACT: Brown, L, Doyle, G, Bruce-Low, S, Domingos, S, Anthony, K, Rowan, F, and Galbraith, A. Postactivation potentiation for Muay Thai kicking performance. J Strength Cond Res 37(10): 2032-2037, 2023-The purpose of this study was to investigate the effects of postactivation potentiation (PAP) on Muay Thai kicking performance based on 3 different rest intervals. Aiming to quantify and indicate timing protocols for conditioning coaches when training athletes using PAP. 17 male (25.3 ± 3.6 years old; 179.3 ± 2.3 cm; 78.0 ± 5.2 kg), experienced Muay Thai fighters completed a standardized warm-up, including a 10-minute cycle on the Wattbike at 60 watts and 30 body mass squats for a dynamic stretch. Subjects then completed a baseline test by striking a PowerKube using the roundhouse and Teep kick techniques. PAP exercise consisted of 4 squat repetitions to maximum effort, followed by a rest period of 2, 5, or 8 minutes. Subjects then struck the PowerKube again using the roundhouse and Teep kick techniques. Rest periods were presented in a randomized order on separate days, with 72 hours between conditions. The level of significance was set at α = 0.05. Significant increases in both roundhouse (χ 2 (3) = 38.51, p < 0.05) and Teep kick (χ 2 (3) = 26.33, p < 0.05) striking power were observed when compared with baseline. For the roundhouse kick, significant differences and large effect sizes were present between all conditions except baseline and 2-minute rest. For the Teep kick, significant differences and large effect sizes were present between baseline and 5-minute rest and baseline and 8-minute rest. This indicates that PAP with 5- or 8-minute rest increased roundhouse and Teep kick power. This research reports that a PAP stimulus from a 4RM squat exercise, followed by a 5- or 8-minute rest period, enhances kick power in trained Muay Thai fighters. This technique provides a readily available, time-efficient method to enhance performance that can be built into the warm-up procedure of athletes before training or competition.


Assuntos
Desempenho Atlético , Artes Marciais , Exercício de Aquecimento , Adulto , Humanos , Masculino , Adulto Jovem , Desempenho Atlético/fisiologia , Exercício Físico , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Postura , Descanso/fisiologia , Artes Marciais/fisiologia
5.
J Sports Sci ; 41(4): 350-357, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37183452

RESUMO

This case study reports on a professional football player (age: 17.6 years) who was referred for sleep monitoring and intervention after reporting excessive night-time awakenings. The player undertook a series of subjective sleep assessments and objective sleep monitoring (activity monitor). Based on the data presented, a sleep hygiene intervention was prescribed. Numerical comparisons were made between pre-intervention (Pre) and post-intervention (Post) values. Objective values were also compared to reference data from a similarly aged professional cohort from the same club (n = 11). Wake episodes per night (Pre: 7.9 ± 3, Post: 4.5 ± 1.9; -43%) and wake after sleep onset (WASO; Pre: 74.3 ± 31.8 mins, Post: 50.0 ± 22.8 mins, -33%) were improved from Pre to Post. Compared to the reference data, mean wake episodes per night (Pre: 7.9 ± 3.0, reference: 4.6 ± 2.6; -42%) and WASO (Pre: 74.3 ± 31.8 mins, reference: 44.3 ± 36.5 mins; -40%) were all lower compared to Pre levels. Whilst causality cannot be proven, we observed multiple sleep metrics improving following an intervention. This provides a potential framework for practitioners looking to provide targeted sleep assessment and intervention.


Assuntos
Futebol Americano , Higiene do Sono , Humanos , Idoso , Adolescente , Polissonografia , Actigrafia , Sono
6.
Int J Sports Med ; 44(5): 336-343, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36347431

RESUMO

This study assessed whether scheduling (start time and day type) and workload variables influenced sleep markers (activity monitor) in professional academy footballers (n=11; 17.3±0.7 yrs) over a 10-week in-season period. Separate linear mixed regressions were used to describe the effect of start time on the previous nights sleep, and the effect of day type (match day, match day+1) and workload on subsequent sleep. Workload variables were modelled by day (day), 7-day (acute), and 28-day (chronic) periods. Sleep duration following match day+1 (400 mins; 95%CI:368-432) was significantly reduced compared to all other day types (p<0.001). Sleep onset time following match day (00:35; CI:00:04-01:12) and wake time on match day+1 (09:00; CI:08:37-09:23) were also significantly later compared to all other day types (p<0.001). Sleep duration (19.1 mins; CI:9.4-28.79), wake time (18 mins; CI:9.3-26.6), and time in bed (16.8 mins; CI:2.0-31.5) were significantly increased per hour delay in start time. When no activity was scheduled, sleep duration (37 mins; CI:18.1-55.9), sleep onset (42.1 mins; CI:28.8-56.2), and wake times (86 mins; CI:72-100) were significantly extended, relative to a 09:00 start time. Day, acute, and chronic workloads were associated with sleep onset and wake times only. Scheduled start times were associated with changes in sleep duration. Therefore, delaying start times may increase sleep in this population.


Assuntos
Futebol Americano , Futebol , Humanos , Adolescente , Sono , Duração do Sono , Carga de Trabalho
7.
Br J Sports Med ; 54(12): 731-738, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30792258

RESUMO

OBJECTIVES: We examined the relation between global positioning system (GPS)-derived workloads and injury in English Premier League football players (n=33) over three seasons. METHODS: Workload and injury data were collected over three consecutive seasons. Cumulative (1-weekly, 2-weekly, 3-weekly and 4-weekly) loads in addition to acute:chronic workload ratios (ACWR) (acute workload (1-week workload)) divided by chronic workload (previous 4-week average acute workload) were classified into discrete ranges by z-scores. Relative risk (RR) for each range was then calculated between injured and non-injured players using specific GPS variables: total distance, low-intensity distance, high-speed running distance, sprint distance, accelerations and decelerations. RESULTS: The greatest non-contact injury risk was when the chronic exposure to decelerations was low (<1731) and the ACWR was >2.0 (RR=6.7). Non-contact injury risk was also 5-6 times higher for accelerations and low-intensity distance when the chronic workloads were categorised as low and the ACWR was >2.0 (RR=5.4-6.6), compared with ACWRs below this. When all chronic workloads were included, an ACWR >2.0 was associated with a significant but lesser injury risk for the same metrics, plus total distance (RR=3.7-3.9). CONCLUSIONS: We recommend that practitioners involved in planning training for performance and injury prevention monitor the ACWR, increase chronic exposure to load and avoid spikes that approach or exceed 2.0.


Assuntos
Traumatismos em Atletas/epidemiologia , Esforço Físico/fisiologia , Futebol/lesões , Futebol/fisiologia , Adulto , Traumatismos em Atletas/fisiopatologia , Sistemas de Informação Geográfica , Humanos , Incidência , Masculino , Condicionamento Físico Humano , Fatores de Risco , Corrida/lesões , Corrida/fisiologia , Análise e Desempenho de Tarefas , Adulto Jovem
8.
Cartilage ; 11(2): 160-168, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-29156985

RESUMO

Objective. Loss of disc height is commonly associated with chronic low back pain (CLBP). Isolated lumbar extension (ILEX) exercise for the lumbar extensors is recommended to treat CLBP and is suggested such exercise might promote disc healing and regeneration. This study examined a 12-week ILEX intervention on indirect determination of disc height and shrinkage through seated stadiometry, strength, pain, and disability. Design. A quasi-experimental wait-list controlled design was used. Nine participants underwent pretesting (T1), a 12-week control period, retesting (T2), a 12-week intervention period, and finally posttesting (T3). Seated stadiometry, ILEX strength, pain, and disability were measured at each time point. Results. No significant repeated-measures effects for any seated stadiometry variables occurred. Significant improvement across the intervention period (T2 to T3) was found for strength (P <0.0001; effect size [ES] = 2.42). Change in pain was not significant for repeated effects (P = 0.064); however, ES for the intervention period (T2 to T3) was moderate (ES = -0.77). Change in disability was significant between time point T1 and T3 (P = 0.037) and ES for the intervention period (T2 to T3) was large (ES = -0.92). Pain and disability achieved minimal clinically important changes. Conclusions. This is apparently the first study to examine disc change in vivo after exercise in CLBP. Results of the present study, though supporting ILEX resistance training to improve strength, pain, and disability, did not find any effect on spinal height.


Assuntos
Antropometria , Dor Crônica/terapia , Dor Lombar/terapia , Treinamento Resistido/métodos , Coluna Vertebral/fisiopatologia , Dor Crônica/fisiopatologia , Avaliação da Deficiência , Feminino , Humanos , Disco Intervertebral/patologia , Dor Lombar/fisiopatologia , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Força Muscular , Medição da Dor , Vértebras Torácicas/fisiopatologia , Resultado do Tratamento
9.
Disabil Rehabil ; 41(11): 1287-1295, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-29327605

RESUMO

PURPOSE: Secondary analysis of data from studies utilising isolated lumbar extension exercise interventions for correlations among changes in isolated lumbar extension strength, pain, and disability. MATERIALS AND METHODS: Studies reporting isolated lumbar extension strength changes were examined for inclusion criteria including: (1) participants with chronic low back pain, (2) intervention ≥ four weeks including isolated lumbar extension exercise, (3) outcome measures including isolated lumbar extension strength, pain (Visual Analogue Scale), and disability (Oswestry Disability Index). Six studies encompassing 281 participants were included. Correlations among change in isolated lumbar extension strength, pain, and disability. Participants were grouped as "met" or "not met" based on minimal clinically important changes and between groups comparisons conducted. RESULTS: Isolated lumbar extension strength and Visual Analogue Scale pooled analysis showed significant weak to moderate correlations (r = -0.391 to -0.539, all p < 0.001). Isolated lumbar extension strength and Oswestry Disability Index pooled analysis showed significant weak correlations (r = -0.349 to -0.470, all p < 0.001). For pain and disability, isolated lumbar extension strength changes were greater for those "met" compared with those "not met" (p < 0.001-0.008). CONCLUSIONS: Improvements in isolated lumbar extension strength may be related to positive and meaningful clinical outcomes. As many other performance outcomes and clinical outcomes are not related, isolated lumbar extension strength change may be a mechanism of action affecting symptom improvement. Implications for Rehabilitation Chronic low back pain is often associated with deconditioning of the lumbar extensor musculature. Isolated lumbar extension exercise has been shown to condition this musculature and also reduce pain and disability. This study shows significant correlations between increases in isolated lumbar extension strength and reductions in pain and disability. Strengthening of the lumbar extensor musculature could be considered an important target for exercise interventions.


Assuntos
Terapia por Exercício/métodos , Dor Lombar , Região Lombossacral , Força Muscular , Músculo Esquelético/fisiopatologia , Adulto , Doença Crônica , Avaliação da Deficiência , Pessoas com Deficiência/reabilitação , Feminino , Humanos , Dor Lombar/diagnóstico , Dor Lombar/fisiopatologia , Dor Lombar/reabilitação , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Medição da Dor , Resultado do Tratamento
10.
J Sports Sci ; 37(2): 156-162, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29932805

RESUMO

This study investigated the effect cadence has on the estimation of critical power (CP) and the finite work capacity (W') during the 3-minute all-out cycling test. Ten participants completed 8 tests: 1) an incremental test to calculate gas exchange threshold (GET), maximal aerobic power (MAP) and peak oxygen uptake (V̇O2peak), 2-4) three time-to-exhaustion tests at 80, 100 and 105% MAP to calculate CP and W', 5-7) four 3-minute all-out tests to calculate end power (EP) and work done above EP (WEP) using cadences ranging from preferred -5 to preferred +10 rev·min-1 to set the fixed resistance. Significant differences were seen between CP and EP-preferred (267.5 ± 22.6 W vs. 296.6 ± 26.1 W, P < 0.001), CP and EP-5 (267.5 ± 22.6 W vs. 303.6 ± 24.0 W, P < 0.001) and between CP and EP+5 (267.5 ± 22.6 W vs. 290.0 ± 28.0 W, P = 0.002). No significant differences were seen between CP and EP+10 (267.5 ± 22.6 W vs. 278.1 ± 30.9 W, P = 0.331). Significant differences were seen between W' and WEP at all tested fixed resistances. EP is reduced when cycling at higher than preferred cadences, providing better estimates of CP.


Assuntos
Teste de Esforço/instrumentação , Teste de Esforço/métodos , Adulto , Limiar Anaeróbio , Humanos , Masculino , Fadiga Muscular/fisiologia , Consumo de Oxigênio , Troca Gasosa Pulmonar , Fatores de Tempo
12.
Healthcare (Basel) ; 5(4)2017 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-29035297

RESUMO

Strengthening the lumbar extensor musculature is a common recommendation for chronic low back pain (CLBP). Although reported as effective, variability in response in CLBP populations is not well investigated. This study investigated variability in responsiveness to isolated lumbar extension (ILEX) resistance training in CLBP participants by retrospective analysis of three previous randomized controlled trials. Data from 77 participants were available for the intervention arms (males = 43, females = 34) 37 participants data (males = 20, females = 17) from the control arms. Intervention participants had all undergone 12 weeks of ILEX resistance training and changes in ILEX strength, pain (visual analogue scale; VAS), and disability (Oswestry disability index; ODI) measured. True inter-individual (i.e., between participants) variability in response was examined through calculation of difference in the standard deviation of change scores for both control and intervention arms. Intervention participants were classified into responder status using k-means cluster analysis for ILEX strength changes and using minimal clinically important change cut-offs for VAS and ODI. Change in average ILEX strength ranged 7.6 Nm (1.9%) to 192.1 Nm (335.7%). Change in peak ILEX strength ranged -12.2 Nm (-17.5%) to 276.6 Nm (169.6%). Participants were classified for strength changes as low (n = 31), medium (n = 36), and high responders (n = 10). Change in VAS ranged 12.0 mm to -84.0 mm. Participants were classified for VAS changes as negative (n = 3), non-responders (n = 34), responders (n = 15), and high responders (n = 19). Change in ODI ranged 18 pts to -45 pts. Participants were classified for ODI changes as negative (n = 2), non-responders (n = 21), responders (n = 29), and high responders (n = 25). Considerable variation exists in response to ILEX resistance training in CLBP. Clinicians should be aware of this and future work should identify factors prognostic of successful outcomes.

13.
Int J Sports Med ; 38(6): 462-467, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28388783

RESUMO

Research suggests that critical power (CP) can be estimated from a single 3-min bout of all-out cycling. The purpose of this study was to investigate the reliability and validity of the 3-min all-out cycling test when carried out at a constant cadence (isokinetic) and against a fixed resistance (linear). 12 participants completed 8 tests: 1) a ramp test; 2-4) 3 fixed power tests to calculate CP and W' using the 1/time mathematical model; 5-8) four 3-min all-out tests to calculate EP and WEP; 2 isokinetic and 2 linear tests. There was no significant difference between EP-isokinetic and CP (P=0.377). There were significant differences between EP-linear and CP (P=0.004), WEP-isokinetic and W' (P<0.001) and WEP-linear and W' (P<0.001). The coefficient of variation in EP-isokinetic, EP-linear, WEP-isokinetic and WEP-linear was 1.93, 1.17, 8.44 and 5.39%, respectively. The 3-min all-out isokinetic test provides a reliable estimate of EP and a valid estimate of CP. The 3-min all-out linear test provides a reliable estimate of EP, but not a valid estimate of CP. Furthermore, these results suggest that the 3-min all-out test should not be used to estimate W'.


Assuntos
Ciclismo/fisiologia , Teste de Esforço/métodos , Adulto , Humanos , Masculino , Consumo de Oxigênio , Reprodutibilidade dos Testes
14.
Appl Ergon ; 53 Pt A: 203-8, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26493099

RESUMO

Indirect measurement of disc hydration can be obtained through measures of spinal height using stadiometry. However, specialised stadiometers for this are often custom-built and expensive. Generic wall-mounted stadiometers alternatively are common in clinics and laboratories. This study examined the reliability of a custom set-up utilising a wall-mounted stadiometer for measurement of spinal height using custom built wall mounted postural rods. Twelve participants with non-specific chronic low back pain (CLBP; females n = 5, males n = 7) underwent measurement of spinal height on three separate consecutive days at the same time of day where 10 measurements were taken at 20 s intervals. Comparisons were made using repeated measures analysis of variance for 'trial' and 'gender'. There were no significant effects by trial or interaction effects of trial x gender. Intra-individual absolute standard error of measurement (SEM) was calculated for spinal height using the first of the 10 measures, the average of 10 measures, the total shrinkage, and the rate of shrinkage across the 10 measures examined as the slope of the curve when a linear regression was fitted. SEMs were 3.1 mm, 2.8 mm, 2.6 mm and 0.212, respectively. Absence of significant differences between trials and the reported SEMs suggests this custom set-up for measuring spinal height changes is suitable use as an outcome measure in either research or clinical practice in participants with CLBP.


Assuntos
Pesos e Medidas Corporais/instrumentação , Dor Crônica , Disco Intervertebral/patologia , Dor Lombar , Coluna Vertebral/patologia , Adulto , Idoso , Feminino , Humanos , Disco Intervertebral/fisiopatologia , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Reprodutibilidade dos Testes
15.
PM R ; 8(2): 105-14, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26107538

RESUMO

BACKGROUND: Chronic low back pain (CLBP) is a multifactorial condition with a variety of symptoms, one of which is abnormal gait. The lumbar spine and its musculature are important in controlling gait, and in CLBP the lumbar extensors are often deconditioned. Because of this specific isolated lumbar extension, exercise often is recommended. It was therefore of interest to examine its effects of upon gait variability. OBJECTIVE: To examine the effects of isolated lumbar extension resistance training on lumbar kinematic variability during gait in participants with CLBP. DESIGN: Randomized controlled trial. SETTING: University Health, Exercise and Sport Science Laboratory. PARTICIPANTS: Twenty-four participants with nonspecific CLBP. INTERVENTIONS: Participants were randomly allocated to a 12-week isolated lumbar extension exercise intervention (1×/week performing a single set to momentary muscular failure using a load equal to 80% max tested torque) or nontraining control period. MAIN OUTCOME MEASUREMENTS: Lumbar kinematics during gait, including angular displacement, kinematic waveform pattern (CVp), and offset (CVo) variability, were examined via 3-dimensional analyses. RESULTS: No significant changes in displacement or CVo were found as a result of the intervention; however, a small but significant reduction in sagittal plane CVp (-20.90 ± 3.53%, effect size = 0.48, P = .044) occurred, indicating improved motor pattern replication through this movement plane. CONCLUSIONS: Considering the role of the lumbar extensors in gait, and their common deconditioning in CLBP, an isolated lumbar extension resistance exercise intervention may reduce gait variability. These results suggest isolated lumbar extension exercise may specifically reduce sagittal plane variability, indicating improved motor pattern replication through this movement plane, perhaps attributable to the plane of movement used during the exercise.


Assuntos
Dor Crônica/reabilitação , Terapia por Exercício , Marcha/fisiologia , Dor Lombar/reabilitação , Vértebras Lombares/fisiopatologia , Adulto , Dor Crônica/fisiopatologia , Feminino , Humanos , Dor Lombar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Medição da Dor , Amplitude de Movimento Articular/fisiologia
16.
Spine J ; 15(10): 2117-21, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26409630

RESUMO

BACKGROUND CONTEXT: Low back pain (LBP) is highly prevalent and presents an enormous cost both through direct health care and indirectly through significant work and production loss. Low back pain is acknowledged widely to be a multifactorial pathology with a variety of symptoms, dysfunctions, and a number of possible sources of pain. One source that has been suspected and evidenced for some time is the intervertebral disc. Some degree of disc degeneration is a physiologic process associated with aging, however, more severe degeneration and/or structural abnormality may be indicative of a pathologic process or injury and is more commonly present in those suffering from LBP. Much like other tissues (ie, muscle, bone, etc.), it has been suspected that there exists an optimal loading strategy to promote the health of the disc. Exercise is often prescribed for LBP and effectively reduces pain and disability. However, whether specific loading through exercise might plausibly heal or regenerate the intervertebral discs is unknown. PURPOSE: To examine the effects of loading on regenerative processes in the intervertebral disc and consider the potential for specific exercise to apply loading to the lumbar spine to produce these effects. STUDY DESIGN: A brief narrative literature review. METHODS: Studies examining the effects of loading on the intervertebral discs were reviewed to examine the plausibility of using loading through exercise to induce regeneration or healing of the intervertebral disc. RESULTS: Research from animal model studies suggests the existence of a dose-response relationship between loading and regenerative processes. Although high loading at high volumes and frequencies might accelerate degeneration or produce disc injury, high loading, yet of low volume and at low frequency appears to induce potentially regenerative mechanisms, including improvements in disc proteoglycan content, matrix gene expression, rate of cell apoptosis, and improved fluid flow and solute transport. CONCLUSIONS: Research suggests a dose-response relationship between loading and disc regenerative processes and that the loading pattern typically used in the lumbar extension resistance exercise interventions (high load, low volume, and low frequency) might impart healing or regeneration of the intervertebral discs. Future research should examine an exercise intervention with in vivo measurement of changes in disc condition. This may provide further evidence for the "black box" of treatment mechanisms associated with exercise interventions.


Assuntos
Exercício Físico , Degeneração do Disco Intervertebral/fisiopatologia , Disco Intervertebral/fisiologia , Regeneração , Animais , Terapia por Exercício , Humanos , Disco Intervertebral/fisiopatologia , Degeneração do Disco Intervertebral/diagnóstico , Degeneração do Disco Intervertebral/terapia , Masculino
17.
PeerJ ; 3: e878, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25861560

RESUMO

Background/Aim. Exercise designed to condition the lumbar extensor musculature is often included in resistance training (RT) programs. It is suggested that deconditioning of this musculature may be linked to low back pain. Thus effective means of conditioning these muscles are of interest to pursue. Evidence suggests that isolated lumbar extension (ILEX) RT might be most efficacious, however, the best means of manipulating resistance training variables in this regard is unknown. Set volume is an easily manipulated RT variable and one thought to also interact with training status. As such this study sought to examine the effect of set volume during ILEX RT in trained males. Methods. Trained males previously engaged in exercises designed to condition the lumbar extensors underwent a 6 week intervention and were randomised to either a single set (1ST, n = 9), multiple set (3ST, n = 8) or control group (CON, n = 9). Pre- and post-testing of ILEX strength was conducted. Results. Both 1ST and 3ST significantly increased ILEX strength (p < 0.05) with large effect sizes (d = 0.89 and 0.95 respectively) whereas the CON group produced significant losses (-8.9%) with a moderate effect size (d = - 0.53). There was no statistically significant difference in ILEX strength gains when 1ST and 3ST were directly compared (p = 0.336). Conclusions. The results of this study suggest that significant ILEX strength changes occur in trained males as a result of 6 weeks of ILEX RT and that these changes are unaffected by set volume.

18.
Artigo em Inglês | MEDLINE | ID: mdl-27900112

RESUMO

AIM: To describe and characterise anthropometrical and fitness changes following a 12-week walking football programme in individuals over the age of 50 years. METHODS: Following ethical approval, 10 male participants (mean (SD): age 66 (7) years) with a range of comorbidities completed a 12-week walking football programme, consisting of a single 2 h training session each week. Body mass, fat mass, fat free mass, maximal oxygen consumption, maximal heart rate, exercise time to exhaustion and isometric hand-grip strength, were assessed at baseline and immediately following the intervention. Week-0-12 intervention differences were determined using means (95% CIs) and t tests; effect sizes were calculated using Cohen's d (0.2 small, 0.5 medium, 0.8 large). RESULTS: 12 weeks walking football significantly reduced body fat mass (week 0, 27.4 (9.0) kg versus week 12, 24.4 (8.9) kg, p=<0.05, d=1.0) and reduced percentage body fat (week 0, 30.3 (8.2) % versus week 12, 27.5 (8.5) %, p=<0.05, d=1.0). A significant increase in time to volitional exhaustion during increamental exercise (week 0, 545 (102) s versus week 12, 603 (102) s, p=<0.05, d=0.7) was observed without any change in peak blood lactate. Non-significant differences with medium effect sizes were seen for a reduction whole body mass, increase in lean body mass and a reduction in body mass index. CONCLUSIONS: This investigation suggests the potential efficacy of walking football as a public health intervention, even in populations presenting a range of comorbidities, with future research investigating its move to scale.

19.
PM R ; 7(2): 169-87, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25452128

RESUMO

OBJECTIVE: Chronic low back pain (CLBP) is prevalent, costly, and acknowledged as multifactorial in nature. However, deconditioning of the lumbar extensor musculature may be a common factor. Thus specific resistance exercise is often recommended. Many resistance exercises for the lumbar extensors exist, although recent evidence suggests that isolated lumbar extension (ILEX) resistance training may best for conditioning these muscles. Thus this review aimed to examine the use of ILEX resistance training in participants with CLBP to provide a best-evidence synthesis for practitioners and clinicians. LITERATURE SURVEY: Reference lists from previous reviews were searched in addition to SPORTDiscus, PubMed, and Google Scholar databases up to May 2014 using search terms including combinations and synonyms of "isolation," "lumbar extension," "lumbar exercise," "lumbar strength," "lumbar endurance," "lumbar spine," "low back exercise," "CLBP," "pain," and "disability." METHODOLOGY: A "snowballing"-style literature search was used that involved an emergent approach. Studies examining ILEX resistance training as an intervention in symptomatic CLBP populations reporting pain, disability, or global perceived outcomes (GPO) as outcomes were examined. Pain and disability were outcomes and were compared to consensus guidelines for minimal clinically important changes. Single case reports were excluded. SYNTHESIS: Results suggest that ILEX resistance training produces significant and meaningful improvements in perceived pain, disability, and GPOs, as part of a multiple intervention or stand-alone approach. A low frequency (once per week) yet high intensity of effort (to momentary muscular failure) approach using either full or limited range-of-motion ILEX resistance training appears to be sufficient and best for significant and meaningful outcomes. Limited comparative studies between ILEX resistance training and other specific exercise approaches exist; however, only limited evidence supports ILEX resistance training as being more effective. CONCLUSIONS: These findings highlight ILEX resistance training as effective for significant and meaningful improvements in perceived pain, disability, and GPOs for CLBP participants. Further research should elucidate comparisons between ILEX resistance training and other specific exercise approaches and should clarify whether lumbar extensor conditioning is the mechanism responsible for the improvements reported.


Assuntos
Dor Crônica/reabilitação , Dor Lombar/reabilitação , Treinamento Resistido , Músculos do Dorso , Humanos , Vértebras Lombares , Resultado do Tratamento
20.
Br J Sports Med ; 49(5): 291-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24092889

RESUMO

OBJECTIVE: To review the specificity of exercises designed to condition the lumbar extensor musculature (ie, lumbar erector spinae and multifidus). METHODS: A review of studies examining effects of exercises designed to condition the lumbar extensors was conducted. Included were studies that examined the acute activation and chronic adaptation of the lumbar extensor musculature in response to benches and roman chair trunk extensions, free weights exercises (ie, deadlifts, squats, good-mornings, etc), floor and stability ball exercise (ie, trunk extensions, bridging, four-point kneeling, etc) and resistance machines (ie, those with and without pelvic restraints). RESULTS: Evidence suggests that the reviewed exercises designed to condition the lumbar extensors all may result in significant activation of this musculature during their performance. However, examination of training studies shows that for benches and roman chair trunk extensions, free weights exercises, floor and stability ball exercise and resistance machines without appropriate pelvic restraints, evidence suggests that they may be less effective for inducing chronic adaptations in the lumbar extensors as a result of their performance. Contrastingly, resistance machines that employ appropriate pelvic restraint to isolate lumbar extension are better evidenced to confer specific adaptations to the lumbar extensors. CONCLUSIONS: Numerous exercise approaches have been designed with the intention of conditioning the lumbar extensors. Those examined appear to activate the lumbar extensors; however, the specificity of many of these exercises for producing chronic adaptations may be questionable, potentially due to the compound nature of them allowing involvement of other musculature such as the hip extensors. Many of the reviewed exercises offer potential to condition the lumbar extensors, however, isolation of lumbar extension through appropriate pelvic restraint appears important for optimising specific adaptations in the lumbar extensors.


Assuntos
Músculos do Dorso/fisiologia , Exercício Físico/fisiologia , Adaptação Fisiológica/fisiologia , Eletromiografia , Humanos , Região Lombossacral/fisiologia , Fadiga Muscular/fisiologia , Força Muscular/fisiologia , Restrição Física
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