Isometric Resistance Exercise Research Articles

Reliability and validity of a low-cost, wireless sensor and smartphone app for measuring force during isometric and dynamic resistance exercises.

The aim of this study was to investigate the reliability and validity of an affordable wireless force sensor in measuring mean and peak forces during resistance training.A Suiff Pro wireless force sensor (Suiff, Spain) and a MuscleLab force platform (Ergotest, Norway) were used concurrently to assess tensile load and the ground reaction force resulting from an upright row exercise. Thirteen participants (28.2 ± 5.7 years, 76.2 ± 9.6 kg, 178.2 ± 9.2 cm) performed the exercise under three velocity conditions and isometrically. Each condition involved three sets of exercise. Mean (Fmean) and peak (Fpeak) force values from both sensors were collected and compared.Suiff Pro exhibited excellent reliability for Fmean and Fpeak (ICCs = 0.99). When compared to the criterion measures, Suiff Pro showed trivial standardized bias for Fmean (Mean = 0.00 [CI 95% = 0.00 to 0.01]) and Fpeak (-0.02 [-0.04 to 0.00]). The standardized typical error was also trivial for Fmean (0.03 [0.02 to 0.03]) and Fpeak (0.07 [0.05 to 0.09]). Correlations with the MuscleLab force platform were nearly perfect: Fmean (0.97 [0.94 to 0.98]; p<0.001); Fpeak (0.96 [0.92 to 0.97]; p<0.001).The findings demonstrate that the Suiff Pro sensor is reliable and valid device for measuring force during isometric and dynamic resistance training exercises. Therefore, practitioners can confidently use this device to monitor kinematic variables of resistance training exercises and to obtain real-time augmented feedback during a training session.

Exercise for Hypertension: New Recommendation Strategies for Blood Pressure Control

ABSTRACT Hypertension is a leading preventable risk factor for cardiovascular disease, stroke, and premature death worldwide. Due to its undeniable antihypertensive effects, exercise training is advised as an effective nonpharmacological method of preventing, treating, and controlling hypertension by the main professional and scientific societies, including the American College of Cardiology, American Heart Association, European Society of Hypertension, American College of Sports Medicine, and Exercise and Sport Science Australia. In this review, we aim to summarize the current recommendations of exercise training for hypertension and discuss the emerging research supporting the integration of new exercise strategies, such as neuromotor and isometric resistance exercise, for the prevention and management of hypertension.

The Effects of High-Load Slow-Velocity Resistance Exercise Training in Athletes With Tendinopathy: A Critically Appraised Topic.

Tendinopathy is a musculoskeletal pathological condition experienced by athletes that can result in pain, impaired muscle performance, and loss of physical function and can hinder return to sports. Various types of resistance exercise training are effective for treating tendinopathy, including isometric, concentric, eccentric, and high-load slow-velocity resistance exercise. What are the effects of high-load slow-velocity resistance exercise training, compared with other forms of resistance exercise, on tendon morphology and patient-reported outcomes in athletes with tendinopathy? The findings of 4 randomized clinical trials were included. One study compared high-load slow-velocity resistance exercise with moderate-load slow-velocity resistance exercise. Two studies investigated the effects of high-load slow-velocity resistance exercise versus eccentric resistance exercise. The fourth study compared high-load slow-velocity resistance exercise with inertia-based resistance exercise. In all of the studies, high-load slow-velocity resistance exercise was as effective as the other forms of resistance exercise for improving patient-reported outcomes and pain. Three studies found no significant differences in changes in tendon morphology between patients who received high-load slow-velocity resistance exercise versus those who received the other forms of resistance exercise. One study showed that high-load slow-velocity resistance exercise was more effective than eccentric exercise for improving tendon morphology outcomes. Current evidence supports the use of high-load slow-velocity resistance exercise as a treatment option for patellar and Achilles tendinopathy in athletes. Results from level 2 studies suggest grade B evidence in support of high-load slow-velocity resistance exercise for treating athletes with tendinopathy.

Effect of Scapular Retraction on Lower Trapezius, Infraspinatus, and Deltoid Muscle Electromyographic Activity During the Side-Lying Abduction Exercise.

The lower trapezius (LT) muscle, which stabilizes the scapula posteriorly during arm elevation, has been interesting to both clinicians and researchers for its importance in throwing-related shoulder rehabilitation and injury prevention. The purpose of this study was to investigate the electromyographic activity of the LT and other relevant muscles during scapular and shoulder activities in the side-lying position. Twenty collegiate baseball players volunteered to participate in this study. Electromyographic (EMG) output of the lower trapezius, infraspinatus, posterior deltoid, middle deltoid, serratus anterior, and upper trapezius muscles were collected. All the subjects performed isometric resistance exercises in four arm positions: 0° horizontal abduction from the coronal plane (NEUT) with protraction (NEUT-PRO), 15° horizontal adduction from the coronal plane (HADD) with protraction (HADD-PRO), and NEUT with retraction (NEUT-RET), and HADD-RET in a side-lying isometric abduction exercise with two external loads: a 9.1 kg dumbbell and 40% of the manual muscle test (MMT). The subjects also performed two more isometric resistance exercises: supine protraction and side-lying external rotation (ER) of the glenohumeral (GH) joint in GH adduction at 90° of GH ER or with as much ER as possible. All raw EMG data were normalized to maximal voluntary isometric contraction (% MVIC) of the corresponding muscle. LT activity was significantly greater in HADD-RET with 9.1 kg than that of HADD-PRO (p < 0.001) (55 vs 21% MVIC) while middle deltoid muscle activity was significantly decreased in both NEUT and HADD-RET compared to that of NEUT and HADD-PRO (p < 0.001). In contrast, IS muscle activity was significantly increased in HADD-RET with 9.1 kg compared with that 40% MMT (p < 0.001) (41 vs 22% MVIC). LT activity was modulated by changes in scapulothoracic and glenohumeral joint positioning during a side-lying isometric abduction exercise. These findings may help clinicians to select exercises to improve scapular muscle balance ratios during rehabilitation of the shoulder complex. Level 3b, Controlled laboratory study.

ASSOCIATION BETWEEN BLOOD PRESSURE AND HAND GRIP STRENGTH AMONG ADULT POPULATION VISITING A TERTIARY CARE CENTRE – A CROSS-SECTIONAL STUDY

Introduction: It has been suggested that isometric handgrip resistance exercise be used as the rst line treatment for hypertension. This cross-sectional study sought to better understand the association between adult individual's systolic and diastolic blood pressures with hand grip strength. The present study is a cross-s Methods: ectional study done among 240 healthy participants aged 19-40 years. Clearance was obtained from Institutional Ethical Committee. Blood pressure was recorded following standard precautions. The average of the maximum handgrip strength from both hands were taken into consideration. General linear models were used to examine the association between handgrip strength and blood pressure. Data was analyzed by Independent t test and Pearson correlation test using software, SPSS version 26. Handgrip strength was signicantly and positively associated Results: with systolic blood pressure (P&lt;0.001), diastolic blood pressure (P&lt;0.001) and body mass Index (P&lt;0.05). There was an increase in systolic blood pressure, diastolic blood pressure and body mass index with increase in handgrip strength. High systolic and diastolic blood pressures w Conclusion: ere associated with increased handgrip strength in both men and women. This aids in controlling blood pressure and might have implications for early prevention

Forelimb Resistance Exercise Protects Against Neuromuscular Junction Denervation in the SOD1-G93A Rat Model of ALS.

The symptoms of Amyotrophic Lateral Sclerosis (ALS) include muscle weakness and eventual paralysis. These symptoms result from denervation of the neuromuscular junction (NMJ) and motor neuron cell death in the brain and spinal cord. Due to the "dying back" pattern of motor neuron degeneration, protecting NMJs should be a therapeutic priority. Although exercise has the potential to protect against NMJ denervation, its use in ALS has been controversial. Most preclinical studies have focused on aerobic exercise, which report that exercise can be beneficial at moderate intensities. The effects of resistance exercise on NMJ preservation in limb muscles have not been explored. We trained male SOD1-G93A rats, which model ALS, to perform a unilateral isometric forelimb resistance exercise task. This task allows within-animal comparisons of trained and untrained forelimbs. We then determined the effects of isometric resistance exercise on NMJ denervation and AMP kinase (AMPK) activation in forelimb muscles. Our results revealed that SOD1-G93A rats were able to learn and perform the task similarly to wildtype rats, even after loss of body weight. SOD1-G93A rats exhibited significantly greater NMJ innervation in their trained vs their untrained forelimb biceps muscles. Measures of activated (phosphorylated) AMPK (pAMPK) were also greater in the trained vs untrained forelimb triceps muscles. These results demonstrate that isometric resistance exercise may protect against NMJ denervation in ALS. Future studies are required to determine the extent to which our findings generalize to female SOD1-G93A rats and to other subtypes of ALS.

Brain oxygenation during multiple sets of isometric and dynamic resistance exercise of equivalent workloads: Association with systemic haemodynamics

ABSTRACT Brain function relies on sufficient blood flow and oxygen supply. Changes in cerebral oxygenation during exercise have been linked to brain activity and central command. Isometric- and dynamic-resistance exercise-(RE) may elicit differential responses in systemic circulation, neural function and metabolism; all important regulators of cerebral circulation. We examined whether (i) cerebral oxygenation differs between isometric- and dynamic-RE of similar exercise characteristics and (ii) cerebral oxygenation changes relate to cardiovascular adjustments occurring during RE. Fourteen men performed, randomly, an isometric-RE and a dynamic-RE of similar characteristics (bilateral-leg-press, 2-min×4-sets, 30% of maximal-voluntary-contraction, equivalent tension-time-index/workload). Cerebral-oxygenation (oxyhaemoglobin-O2Hb; total haemoglobin-tHb/blood-volume-index; deoxyhemoglobin-HHb) was assessed by NIRS and beat-by-beat haemodynamics via photoplethysmography. Cerebral-O2Hb and tHb progressively increased from the 1st to 4th set in both RE-protocols (p < 0.05); HHb slightly decreased (p < 0.05). Changes in NIRS-parameters were similar between RE-protocols within each exercise-set (p = 0.91–1.00) and during the entire protocol (including resting-phases) (p = 0.48–0.63). O2Hb and tHb changes were not correlated with changes in systemic haemodynamics. In conclusion, cerebral oxygenation/blood-volume steadily increased during multiple-set RE-protocols. Isometric- and dynamic-RE of matched exercise characteristics resulted in similar prefrontal oxygenation/blood volume changes, suggesting similar cerebral haemodynamic and possibly neuronal responses to maintain a predetermined force.

A comparison of teres minor and infraspinatus muscle activation in the prone position.

BackgroundThe electromyography (EMG) activity of the teres minor (TMi) and infraspinatus (IS) muscle has been demonstrated to vary depending on the arm position, such as in the coronal or scapular position, during intervention exercises. This may be reflected by different EMG activities demonstrated between the TMi and IS muscle during the acceleration and deceleration phases of the pitching motion. Tenderness in the scapular attachment site of the TMi muscle is often seen in baseball pitchers after pitching but not the attachment site of the IS muscle. However, few studies have investigated an interaction between TMi and IS muscle activity across different resistance exercises with different arm positions. The purpose of this study was to identify the feature of TMi and IS muscle activity in the presence of manual resistance applied in the prone position.MethodsEighteen collegiate baseball players volunteered their participation. Raw EMG amplitudes of the TMi, IS, posterior deltoid, middle deltoid, and upper trapezius muscles on the dominant shoulder were measured during intervention exercises. All subjects performed manual isometric resistance exercises: horizontal abduction (HABD) and external rotation (ER) of the glenohumeral joint with 40% of the manual maximum strength test in prone. The subjects also performed each of the HABD and ER resistance exercises with the arm actively positioned at 0° and 45° of ER of the glenohumeral joint in the coronal and scapular planes.ResultsBoth TMi and IS muscle activities significantly increased with the arm positioned at 45° of ER compared with 0° of ER regardless of the exercise (P < .05). TMi activity was significantly greater with HABD resistance than IS muscle activity regardless of the arm positions, whereas it was significantly less with ER resistance than IS muscle activity.ConclusionThe findings of this study indicated that the TMi and IS muscles were most highly activated during the HABD resistance with the arm actively positioned at 45° of ER in the coronal plane. The results of this study have clinical implications regarding the careful selection of arm position in both exercise and clinical examination for the TMi and IS muscles.

Muscle Oxygenation, Neural, and Cardiovascular Responses to Isometric and Workload-matched Dynamic Resistance Exercise.

Differences in blood flow patterns and energy cost between isometric and dynamic resistance exercise may result to variant cardiovascular, neural, and muscle metabolic responses. We aimed to compare the cardiovascular, baroreceptor sensitivity, and muscle oxygenation responses between workload-matched, large muscle-mass isometric and dynamic resistance exercises. Twenty-four young men performed an isometric and a dynamic double leg-press protocol (4 sets×2 min) with similar tension time index (workload). Beat-by-beat hemodynamics, baroreceptor sensitivity, muscle oxygenation, and blood lactate were assessed. The increase in blood pressure was greater (p<0.05) in the 1st set during dynamic than isometric exercise (by ~4.5 mmHg), not different in the 2nd and 3rd sets, and greater in the 4th set during isometric exercise (by ~5 mmHg). Dynamic resistance exercise evoked a greater increase in heart rate, stroke volume, cardiac output, and contractility index (p<0.05), and a greater decline in peripheral resistance, baroreceptor sensitivity, and cardiac function indices than isometric exercise (p<0.05). Participants exhibited a greater reduction in muscle oxyhemoglobin and a greater increase in muscle deoxyhemoglobin in dynamic versus isometric exercise (p<0.001-0.05), with no differences in total hemoglobin and blood lactate. In conclusion, large muscle-mass, multiple-set isometric exercise elicits a relatively similar blood pressure but blunted cardiovascular and baroreceptor sensitivity responses compared to workload-matched dynamic resistance exercise. Differences in blood pressure responses between protocols appear small (~5 mmHg) and are affected by the number of sets. The muscle oxidative stimulus is greater during dynamic resistance exercise than workload-matched isometric exercise.

Design, development, and evaluation of upper and lower limb orthoses with intelligent control for rehabilitation

World's ageing population, prevalence of chronic diseases, and shortage of healthcare resources have increased interest in home-based physical therapy and rehabilitation. However, the standard equipment is often too bulky and unsuited for home use. This paper presents the design, development, and evaluation of a set of wearable orthoses for home-based physical therapy. Originatively utilising miniature electromagnetic brakes, the system can deliver a low to moderate range of resistive torques suitable for isotonic, isometric, and open-chain resistance exercises. In human tests with the orthoses, low-level muscle activation and low- to moderate-level energy expenditure were achieved. This suggests the system's potential for use in a wide range of applications, including postoperative treatments for muscle injury and the early stages of rehabilitation, and tele-rehabilitation. The orthoses were integrated with a video game console to form a new research platform that can be used to study the effects of force haptics on muscle activation and energy expenditure in exergames. The data obtained aid the future development of exergame prescription standards.

EFFECTS OF EXERCISE TRAINING ON ARTERIAL STIFFNESS IN PATIENTS WITH HYPERTENSION: A SYSTEMATIC REVIEW AND META-ANALYSIS

Objective: This review aims to determine the effects of exercise training on arterial stiffness, namely Pulse Wave Velocity (PWV), in patients with hypertension. The identification of possible moderator variables of the effect of exercise on PWV was defined as a secondary objective. Design and Methods: For this systematic review and meta-analysis (PROSPERO CRD42019138658), MEDLINE, Scopus, Cochrane and Web of Science were searched up until July 2019. Randomized controlled trials assessing the effect of exercise interventions lasting 4 or more weeks on PWV in (pre)hypertensive subjects were included. The standardized mean difference between the pre-post of the intervention group versus the control group was calculated for PWV using the Cohen's d index as the effect size statistic. The type of exercise, PWV assessment site, use of medication, baseline PWV and study quality assessment score were used to perform subgroup analysis. Design and method: Fourteen trials, involving 15 exercise groups (5 aerobic, 2 dynamic resistance, 6 combined, and 2 isometric resistance groups), totaling 694 subjects with pre- and hypertension (374 exercise). Exercise program duration ranged from 4 to 26 weeks, with a mean duration of 13.1 ± 6.1 weeks. The overall effect size showed statistically significant differences in PWV [(d (95% CI) = 1.35 (0.72, 1.98)] in favor of the exercise group. Aerobic exercise [d (95% CI) = 1.93 (0.31, 3.55)], combined exercise [d (95% CI) = 0.79 (0.09, 1.49)] and isometric resistance exercise [d (95% CI) = 2.23 (1.66, 2.81)] reduced PWV for the exercise group when compared to the control group. There was no significant reduction in PWV in subjects undertaking dynamic resistance training [d (95% CI) = 0.69 (-2.32, 3.69)]. Subgroup analysis demonstrated that the positive effects of exercise training on PWV are independent of medication use, PWV assessment site, study quality assessment score and baseline PWV, although higher baseline PWV values presented a more significant reduction with exercise. Results: Aerobic, combined and isometric resistance exercise significantly decreased PWV in (pre)hypertensive patients. Despite the small number of studies, data from the isometric resistance exercise has the potential for the largest reductions in PWV.

POS-293 Physical Activity In Renal Disease (PAIRED) and the effect on hypertension: a randomized controlled trial

Hypertension is a key determinant of both cardiovascular (CV) events and progressive renal dysfunction in people with chronic kidney disease (CKD). Exercise is an effective strategy for blood pressure (BP) reduction in the general population but in CKD, hypertension is mediated by advanced vascular stiffness and volume expansion, and it is unclear whether exercise will mitigate this. The primary aim of this randomized trial was to determine the effect of exercise training compared to usual care on 24-hour ambulatory systolic blood pressure (SBP) in people with CKD at eight weeks. Participants with an eGFR of 15-44 ml/min per 1.73m2 and SBP >120 mmHg were recruited from a single center Canadian renal program. Participants were randomized, stratified by eGFR (<30 versus ≥30), to receive thrice weekly, moderate intensity aerobic exercise (50–60% heart rate reserve) supplemented with isometric resistance exercise, targeting 150 minutes per week and delivered over 24-weeks, or usual care. For exercise participants, Phase 1 (eight weeks) included an in-center weekly session and home-based sessions, and Phase 2 (16 weeks) included home-based sessions. The primary outcome was the difference in 24-h ambulatory SBP after 8 weeks of exercise training compared to control. Secondary outcomes included markers of CV risk, arterial stiffness (pulse wave velocity), aerobic capacity as measured by cardiopulmonary exercise testing and physical activity as measured by 7-day accelerometry. Outcomes were analyzed using mixed linear regression including fixed effects terms for time point, intervention, baseline eGFR, the outcome variable measured at baseline, and a random effects term for participant. Missing values were multiply imputed using chained equations with predictive mean matching. 44 people were randomized (30% of target enrolment) prior to stopping due to COVID-19. Of those randomized, 36% were female, mean age was 66, 55% were diabetic, and mean GFR was 29. Eligibility was 25%, primarily due to transportation barrier to attend the in-center sessions. Compared with usual care, there was no significant change in 24-ambulatory SBP at eight weeks 2.86 mmHg (95% CI -2.64, 8.35; P=0.31) or 24 weeks. There was no significant change in arterial stiffness as measured by pulse wave velocity. VO2peak improved by 235 ml/min in the exercise group (95% CI 18, 452; P=0.03) and there was a significant increase in BMI at 8 weeks 2.01 kg/m2 (95% CI 0.13, 3.89; 0.04) which was reflected in an increase in kilograms of fat free mass but this was not sustained at 24 weeks. The daily mean step count did not differ significantly between groups at 8 weeks, -62 (95% CI -821, 698) or at 24 weeks. In Phase 1, 90% of participants initiated at least 70% of the prescribed sessions versus only 48% of participants in Phase 2. Exercise training improved VO2peak and optimized body composition in people with moderate to severe CKD. However, the trial was under powered to detect a difference in blood pressure and additional trials are needed. To address limitations to trial recruitment resulting from a lack of transportation as well as the pandemic, effective home-based exercise interventions are needed.

Impact of isometric and concentric resistance exercise on pain and fatigue in fibromyalgia.

The aim of this study was to determine the local and systemic effects of isometric and concentric muscle contractions on experimental pain and performance fatigability in people with and without fibromyalgia. Forty-seven fibromyalgia (FM: 51.3 ± 12.3year) and 47 control (CON: 52.5 ± 14.7year) participants performed submaximal isometric and concentric exercise for 10 min with the right elbow flexors. Assessments before and after exercise included pressure pain thresholds (PPT) of the biceps and quadriceps, central pain summation, self-reported exercising arm and whole-body pain, and maximal voluntary isometric contraction (MVIC) of the right elbow flexors and left handgrip. People with FM experienced greater reductions in local fatigue (right elbow flexor MVIC: CON: - 4.0 ± 6.7%, FM: - 9.8 ± 13.8%; p = 0.013) and similar reductions in systemic fatigue (left handgrip MVIC: - 6.5 ± 10.2%; p < 0.001) as CON participants, which were not different by contraction type nor related to baseline clinical pain, perceived fatigue, or reported pain with exercise. Following exercise both groups reported an increase in PPTs at the biceps (pre: 205.5 ± 100.3kPa, post: 219.0 ± 109.3kPa, p = 0.004) only and a decrease in central pain summation (pre: 6.8 ± 2.9, post: 6.5 ± 2.9; p = 0.013). FM reported greater exercising arm pain following exercise (CON: 0.7 ± 1.3, FM: 2.9 ± 2.3; p < 0.001), and both groups reported greater arm pain following concentric (isometric: 1.4 ± 2.0, concentric: 2.2 ± 2.9; p = 0.001) than isometric exercise. Neither group reported an increase in whole-body pain following exercise. People with FM experienced greater performance fatigability in the exercising muscle compared to CON that was not related to central mechanisms of fatigue or pain. These results suggest changes in performance fatigability in FM may be due to differences occurring at the muscular level. TRIAL REGISTRATION #: NCT #: NCT03778385, December 19, 2018, retrospectively registered. IRB#: HR-3035.

Óleo essencial de eucalipto e resposta cardiovascular em idosos após sessão aguda de exercício isométrico

O objetivo do trabalho foi investigar o efeito agudo do óleo essencial de eucalipto (OEE) nas respostas cardiovasculares de repouso e após sessão de exercício resistido isométrico (ERI). Vinte idosos, após serem submetidos a sessões experimentais com inalação de OEE ou condição controle, permaneceram em recuperação durante 60 min (Rec-60’) para depois realizaram três séries de 1 min (1 min de recuperação entre séries) no ERI, para membro superior dominante em aparelho de preensão manual, com intensidade de 30% da contração voluntária máxima (ERI-30%). Intervalos R-R (iRR) e medidas no domínio da frequência (low frequency – LF e high frequency – HF) além da pressão arterial (PA), frequência cardíaca (FC) e duplo produto (DP) foram avaliados. Não ocorreram diferenças (p&gt;0,05) quando comparadas as sessões (OEE vs.controle) na Rec-60’ e ERI-30%. Diferenças foram encontradas no fator tempo do repouso para Rec-60’ nas variáveis FC e iRR e do repouso para ERI-30% na PA sistólica, PA diastólica e DP. A inalação do OEE não proporcionou alterações significativas nas respostas cardiovasculares e autonômicas de idosos no repouso e após sessão de ERI-30%.

Exercise training reduces arterial stiffness in adults with hypertension: a systematic review and meta-analysis.

Arterial stiffness, namely pulse wave velocity (PWV), is an emerging biomarker in the assessment of vascular health. This meta-analysis aims to determine the effects of exercise training on PWV in patients with hypertension, and to identify the possible moderator variables (e.g. type of exercise) of the effect of exercise on PWV. MEDLINE, EMBASE, Cochrane and Web of Science were searched up until July 2019 for randomized controlled trials assessing the effect of exercise interventions lasting 4 or more weeks on PWV in adults with hypertension. Random-effects modelling was used to compare changes from pre to postintervention in PWV between exercise and control groups. Data were reported as weighted mean difference (WMD) and 95% confidence interval (95% CI). Protocol registration: PROSPERO registration number CRD42019138658. We included 14 trials (15 interventions), involving five aerobic, two dynamic resistance, six combined and two isometric resistance groups, totalling 642 participants with hypertension. PWV was significantly reduced by exercise training [(WMD (95% CI) = -0.76 m/s (-1.05 to -0.47)]. Analysis of moderator variables showed that aerobic exercise [WMD (95% CI) = -0.70 m/s (-1.20 to -0.19)], combined exercise [WMD (95% CI) = -0.74 m/s (-1.41 to -0.08)] and isometric resistance exercise [WMD (95% CI) = -0.98 m/s (-1.24 to -0.73)] reduced PWV. There was no significant reduction in PWV in participants undertaking dynamic resistance training [WMD (95% CI) = -0.58 (-1.58 to 0.42)]. This meta-analysis supports that exercise interventions based on aerobic, combined or isometric exercise are suitable to improve PWV in adults with hypertension.

The Application of Double Elastic Band Exercise in the 90/90 Arm Position for Overhead Athletes

Traditional exercises performed with the shoulder in the position of 90° abduction and external rotation with elbow flexion (90/90) while using a single elastic band showed moderate activity of both the lower trapezius (LT) and infraspinatus (IS) muscle. The purpose of this study was to investigate activity of the teres minor (TMi) and the LT muscles during standing external rotation exercise with the shoulder in the 90/90 position with 2 elastic bands in both the frontal and the scapular plane. TMi, IS, and LT muscle activities will vary depending on whether the shoulder is positioned in the frontal or scapular plane with the application of 2 elastic bands. Also, the serratus anterior (SA) and teres major (TMa) muscles will produce different muscular activity patterns during exercises performed with 2 elastic bands in the frontal plane compared with the TMi and LT muscles. Controlled laboratory study. Level 4. A total of 21 collegiate baseball players volunteered to participate. The electromyography (EMG) activities of the TMi, IS, LT, SA, TMa, middle deltoid (MD), posterior deltoid, and upper trapezius (UT) muscles were measured with the 90/90 arm position during both isometric and oscillation resistance exercises with 2 elastic bands oriented in the frontal and scapular planes. A significant difference was observed in EMG activity of both the TMi and the LT muscles between single and double elastic band applications in the frontal plane (P < 0.05). In contrast, EMG activity of the IS, SA, and TMa muscles was significantly increased in the scapular plane compared with the frontal plane (P < 0.05). The standing 90/90 position effectively increased both TMi and LT muscle EMG activity with the double elastic band in the frontal plane while minimizing UT and MD muscle activity. EMG activity of the IS, SA, and TMa muscles increased with exercise in the scapular plane as compared with the frontal plane. Oscillation movement under double elastic band application differentiated external rotator muscle and scapular muscle activities between the frontal and scapular plane during the 90/90 exercise in the frontal plane compared with the scapular plane. Clinicians can utilize each of the scapular and frontal positions based on their desired focus for muscular activation.

Are Blood Pressure and Cardiovascular Stress Greater in Isometric or in Dynamic Resistance Exercise?

Medical and sports medicine associations are reluctant to endorse isometric exercise to the same extent as dynamic resistance exercise (RE). The major concern is the fear of greater increases in blood pressure (BP) that might be associated with isometric exercise. This review comprehensively presents all human studies that directly compared the magnitude of hemodynamic responses between isometric and dynamic RE. We also discuss possible mechanisms controlling BP-response and cardiovascular adjustments during both types of RE. The most prominent finding was that isometric and dynamic RE using small-muscle mass evoke equal increases in BP; however, the circulatory adjustments contributing to this response are different in dynamic and isometric RE. In contrast, studies using large-muscle mass report inconsistent results for the magnitude of BP-response between the two types of RE. Thus, when the same muscles and workloads are used, the increase in BP during isometric and dynamic RE is more comparable to what is commonly believed. However, it should be noted that only a few studies equalized the workload in two types of RE, most used small sample sizes, and all studies employed healthy participants. More studies are needed to compare the cardiovascular risks associated with isometric and dynamic RE, especially in individuals with chronic disease.

The Effects of Red Spinach Extract Supplementation on Isometric Strength, Resistance Exercise and Cognitive Performance

The Effects of Red Spinach Extract Supplementation on Isometric Strength, Resistance Exercise and Cognitive Performance

Cerebrovascular haemodynamics during isometric resistance exercise with and without the Valsalva manoeuvre.

To examine the interactive effects of VM and isometric resistance exercise on cerebral haemodynamics. Eleven healthy participants (mean ± SD 28 ± 9years; 2 females) completed 20-s bilateral isometric leg extension at 50% of maximal voluntary contraction with continued ventilation (RE), a 20-s VM at mouth pressure of 40mmHg (VM), and a combination (RE + VM), in randomised order. Mean beat-to-beat blood velocity in the posterior (PCAvmean) and middle cerebral arteries (MCAvmean), vertebral artery blood flow, end-tidal partial pressure of CO2 and mean arterial pressure (MAP) were measured. RE data were time aligned to RE + VM and analysed according to standard VM phases. Interaction effects (VM phase×condition) were observed for MCAvmean, PCAvmean, vertebral artery blood flow and MAP (all ≤ 0.010). Phase I MCAvmean was greatest for RE [88 ± 19, vs. 71 ± 11 and 78 ± 12cm s-1 for VM (P = 0.008) and RE + VM (P = 0.021), respectively]. Greater increases in MCAvmean than PCAvmean occurred in phase I of RE only (24 ± 15% vs. 16 ± 16%, post hoc P = 0.044). In phase IIb, MAP was lower in RE than RE + VM (115 ± 15 vs. 138 ± 21mmHg, P = 0.004), but did not reduce MCAvmean (78 ± 8 vs. 79 ± 9cm s-1, P = 0.579) or PCAvmean (45 ± 11 vs .46 ± 11cm s-1, P = 0.617). Phase IIb MCAvmean and PCAvmean was lowest in VM (66 ± 6 and 39 ± 8cm s-1, respectively, all P < 0.001), whereas in Phase IV, MCAvmean, PCAvmean and MAP were greater in VM than in RE and RE + VM (all P < 0.020). RE and RE + VM produce similar cerebrovascular responses despite different MAP profiles. However, the VM produced the greatest cerebrovascular challenge afterward.

Effectiveness of physical activity in the prevention and treatment of hypertension: A mini review

Physical activity (PA) is associated with a clear decrease in blood pressure (BP) and cardiovascular mortality in both men and women. The aim of this review was to evaluate the effectiveness of PA as an adjunct therapy in support of the prevention and pharmacological treatment of hypertension. Studies that reported on the correlation of PA and exercise on BP control among hypertensive patients from 1994 to 2019 were evaluated. PubMed electronic database was utilized. The MeSH system was used to extract relevant research studies from PubMed using the following keywords: “Exercise,” “training,” “hypertension,” “blood pressure,” “systematic review,” and “meta-analysis,” All selected articles were published in English. Sedentariness negatively affects cardiometabolic health, body composition, and BP among hypertensive patients, whereas PA significantly improves cardiometabolic parameters and body composition and leads to an overall improvement in cardiac parasympathetic system by increasing vagal tone, causing a reduction in resting heart rate, and systolic BP in hypertensive adults. Exercise should be tailored according to patient's clinical and functional status to avoid imposing variable internal training load on the patients. Moderate intensity aerobic, isometric and dynamic resistance exercise training alone, or a combination was equally effective in lowering BP among hypertensive adults.