Effect Of High-intensity Resistance Exercise Research Articles

Acute Responses to High-Intensity Back Squats with Bilateral Blood Flow Restriction.

This study examined the acute effects of high-intensity resistance exercise with blood flow restriction (BFR) on performance and fatigue, metabolic stress, and markers of inflammation (interleukin-6 (IL-6)), muscle damage (myoglobin), angiogenesis (vascular endothelial growth factor (VEGF)). Thirteen resistance-trained participants (four female, 24.8 ± 4.7 years) performed four sets of barbell back-squats (75% 1RM) to failure under two conditions: blood flow restriction (BFR, bilateral 80% occlusion pressure) and control (CTRL). Completed repetitions and pre-post-exercise changes in maximal voluntary isometric contractions, countermovement jump, barbell mean propulsive velocity, and surface electromyography were recorded. Pre-post blood lactate (BLa) and venous blood samples for analysis of IL-6, myoglobin, and VEGF were collected. Ratings of perceived exertion (RPE) and pain were recorded for each set. Fewer repetitions were performed during BFR (25.5 ± 9.6 reps) compared to CTRL (43.4 ± 14.2 reps, p < 0.001), with greater repetitions performed during sets 1, 2, and 4 (p < 0.05) in CTRL. Although RPE between conditions was similar across all sets (p > 0.05), pain was greater in BFR across all sets (p < 0.05). Post-exercise fatigue was comparable between conditions. BLa was significantly greater in CTRL compared to BFR at two minutes (p = 0.001) but not four minutes post-exercise (p = 0.063). IL-6 was significantly elevated following BFR (p = 0.011). Comparable increases in myoglobin (p > 0.05) and no changes in VEGF were observed (p > 0.05). BFR increases the rate of muscular fatigue during high-intensity resistance exercise and acutely enhances IL-6 response, with significantly less total work performed, but increases pain perception, limiting implementation.

The Immediate Effect of Parachute-Resisted Gallop on Heart Rate, Running Speed and Stride Frequency in Dogs.

Simple SummaryPhysical fitness is needed for canine athletes and working dogs to optimize their performance in various disciplines. Application of resistance on movements causes biomechanical and cardiorespiratory responses to physical exercise. However, there is still a lack of research on the effects of high-intensity resistance exercise on cardiorespiratory fitness components such as heart rate in canine athletes. In this article, we investigate the short-term effects of parachute-resisted galloping on heart rate, running speed and stride frequency. Healthy dogs of various breeds were extensively studied in five experimental single cases. The dogs ran on a straight 200 m course with and without resistive drag force applied by a parachute attached to their harness while heart rate, running speed and stride frequency were measured. Subsequently, the measurements were compared to baseline phases at rest. In the present trials we found that heart rate increases similarly with and without parachute-resistance while dogs galloped at lower speeds and with increased stride frequency with applied drag force. Our findings lead us to suggest that parachute-resisted galloping is a clinically applicable exercise in healthy dogs to achieve instant cardiorespiratory response.Physical fitness is required for canine athletes and working dogs to optimize performance in various disciplines. There is a lack of research on the effects of resistance exercise on cardiorespiratory variables in dogs. The aim of this study was to investigate the immediate effects of parachute-resisted (PR) gallop on heart rate, running speed and stride frequency compared to unresisted (UR) gallop in dogs. Five N-of-1 trials RCTs with alternating interventions were implemented. Dogs ran on a 200 m course with and without resistive force applied by a parachute attached to their harness while cardiac inter-beat intervals (IBI), running speed and stride frequency were measured. The results were visually displayed and interpreted in graphs and percentage of non-overlapping data estimated effect size. Both interventions showed large effects on heart rate compared to resting values. Mean IBI increased (10–17%) during PR gallop compared to UR gallop although this change was small relative to decreased running speed (19–40%) and increased stride frequency (18–63%). Minimum IBI showed no difference between interventions indicating similar maximum heartbeat per minute. In conclusion, parachute-resistance resulted in dogs galloping at lower speeds at the same cardiorespiratory level of intensity, which may be useful in canine physical rehabilitation and fitness training.

Acute Effects of High-intensity Resistance Exercise on Cognitive Function.

The purpose of the present study was to examine the influence of an acute bout of high-intensity resistance exercise on measures of cognitive function. Ten men (Mean ± SD: age = 24.4 ± 3.2 yrs; body mass = 85.7 ± 11.8 kg; height = 1.78 ± 0.08 m; 1 repetition maximum (1RM) = 139.0 ± 24.1 kg) gave informed consent and performed a high-intensity 6 sets of 10 repetitions of barbell back squat exercise at 80% 1RM with 2 minutes rest between sets. The Automated Neuropsychological Assessment Metrics (ANAM) was completed to assess various cognitive domains during the familiarization period, immediately before, and immediately after the high-intensity resistance exercise bout. The repeated measures ANOVAs for throughput scores (r·m-1) demonstrated significant mean differences for the Mathematical Processing task (MTH; p < 0.001, η2p = 0.625) where post hoc pairwise comparisons demonstrated that the post-fatigue throughput (32.0 ± 8.8 r·m-1) was significantly greater than the pre-fatigue (23.8 ± 7.4 r·m-1, p = 0.003, d = 1.01) and the familiarization throughput (26.4 ± 5.3 r·m-1, p = 0.024, d = 0.77). The Coded Substitution-Delay task also demonstrated significant mean differences (CDD; p = 0.027, η2p = 0.394) with post hoc pairwise comparisons demonstrating that the post-fatigue throughput (49.3 ± 14.4 r·m-1) was significantly less than the pre-fatigue throughput (63.2 ± 9.6 r·m-1, p = 0.011, d = 1.14). The repeated measures ANOVAs for reaction time (ms) demonstrated significant mean differences for MTH (p < 0.001, η2p = 0.624) where post hoc pairwise comparisons demonstrated that the post-fatigue reaction time (1885.2 ± 582.8 ms) was significantly less than the pre-fatigue (2518.2 ± 884.8 ms, p = 0.005, d = 0.85) and familiarization (2253.7 ± 567.6 ms, p = 0.009, d = 0.64) reaction times. The Go/No-Go task demonstrated significant mean differences (GNG; p = 0.031, η2p = 0.320) with post hoc pairwise comparisons demonstrating that the post-fatigue (285.9 ± 16.3 ms) was significantly less than the pre-fatigue (298.5 ± 12.1 ms, p = 0.006, d = 0.88) reaction times. High-intensity resistance exercise may elicit domain-specific influences on cognitive function, characterized by the facilitation of simple cognitive tasks and impairments of complex cognitive tasks.

Effect of high-intensity resistance exercise on cardiometabolic health in older men with osteosarcopenia: the randomised controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)

ObjectivesSarcopenia is related to the metabolic syndrome (MetS), a cluster of cardiometabolic risk-factors (CRF). Most exercise trials apply aerobic rather than resistance exercise to address CRF, while the strategy for...

Music attenuates a widened central pulse pressure caused by resistance exercise: A randomized, single-blinded, sham-controlled, crossover study

Increasing central blood pressure is an independent predictor of cardiovascular disease and is an acute effect of high-intensity resistance exercise. It has been shown that classical music suppresses increased peripheral pressure during exercise. We hypothesized that classical music would suppress increased central pressure induced by high-intensity resistance exercise. To confirm this hypothesis, we examined the effect of classical music on central pressure following high-intensity resistance exercise in 18 young men. A randomized, single-blinded, sham-controlled, crossover trial was conducted under parallel experimental conditions on four separate days. The order of experiments was randomized between sham control (seated rest), music (20-min classical music track compilation), resistance exercise (5 sets of 10 repetitions at 75% of 1 repetition maximum), and resistance exercise with music conditions. Aortic pressure was measured in all subjects. No significant interaction between time, music, and resistance exercise was observed for aortic systolic pressure and diastolic pressure. In contrast, aortic pulse pressure showed a significant interaction; that is, aortic pulse pressure significantly widened after resistance exercise, whereas music significantly attenuated this widening. No significant change was observed in aortic pulse pressure in sham control and music conditions. The present findings suggest that music attenuates resistance exercise-induced increase in central pressure.

Experimental Effects of Acute High-Intensity Resistance Exercise on Episodic Memory Function: Consideration for Post-Exercise Recovery Period.

BackgroundThe present experiments evaluated the effects of acute high-intensity resistance exercise on episodic memory.MethodsTwo experiments were conducted. For Experiment 1, participants (N = 40; Mage = 21.0 years) were randomized into one of two groups, including an experimental exercise group and a control group (seated for 20 min). The experimental group engaged in an acute bout of resistance exercises (circuit style exercises) for 15 minutes, followed by a 5-min recovery period. Memory function was subsequently assessed using a multiple trial (immediate and delay), word-list episodic memory task (Rey Auditory Verbal Learning Test, RAVLT), and then followed by a comprehensive, computerized assessment of episodic memory (Treasure Hunt task, THT). The THT involved a spatio-temporal assessment of what, where, and when components of episodic memory. Experiment 2 evaluated if altering the recovery period would influence the potential negative effects of high-intensity resistance exercise on episodic memory function. For Experiment 2, participants (N = 51) were randomized into the same acute resistance exercise protocol but either with a 10-min recovery period, 20-min recovery period, or a control group.ResultsFor Experiment 1, for RAVLT, the exercise group performed worse (Fgroup × time = 3.7, p = .001, η2p = .09). Across nearly all THT outcomes, the exercise group had worse spatio-temporal memory than the control group. These results suggest that high-intensity resistance exercise (with a 5-min recovery) may have a detrimental effect on episodic memory function. For Experiment 2, for RAVLT, the exercise with 10-min recovery group performed better (Fgroup × time = 3.1, p = .04, η2p = .11). Unlike Experiment 1, exercise did not impair spatio-temporal memory, with the 20-min exercise recovery group having the best “where” component of episodic memory.ConclusionCollectively, the results from these two experiments suggest that acute high-intensity resistance exercise may impair episodic memory when a short exercise recovery period (e.g., 5-min) is employed, but with a longer recovery period (10+ min), acute high-intensity resistance exercise may, potentially, enhance episodic memory.

Aortic diastolic pressure decay modulates relation between worsened aortic stiffness and myocardial oxygen supply/demand balance after resistance exercise.

High-intensity resistance exercise (RE) increases aortic stiffness and decreases the index of myocardial oxygen supply/demand balance (Buckberg index, BI); there is a correlation between the changes in these parameters. Central hemodynamics during diastole can explain the correlation. We aimed to investigate whether the aortic diastolic decay index mediates the association between changes in aortic stiffness and BI by high-intensity RE. We evaluated the effect of high-intensity RE on aortic stiffness, BI, aortic decay index, and their associations in 52 young men. Subjects were studied under parallel experimental conditions on two separate days. The order of experiments was randomized between RE (5 sets of 10 repetitions at 75% of 1-repetition maximum) and sham control (seated rest). Aortic pulse wave velocity (PWV; index of aortic stiffness), BI, and aortic decay index were measured in all subjects. Aortic decay index was quantified by fitting an exponential curve: P(t) = P0e-λt (where λ is decay index, P0 is end-systolic pressure and t is time from end-systole). Aortic PWV and decay index increased and BI decreased after RE. RE conditions showed that change in the aortic decay index was associated with changes in aortic PWV and changes in aortic PWV were related to changes in BI, although the PWV-BI relationship was not significant after accounting for decay index change. Mediation analysis revealed the mediating effect of the aortic decay index on the relationship between changes in aortic PWV and BI. The present findings suggest that high-intensity RE-induced aortic stiffening worsens myocardial viability by accelerating aortic diastolic exponential decay.NEW & NOTEWORTHY Aortic pulse wave velocity (PWV) and diastolic decay index increased and Buckberg index (BI) decreased after resistance exercise (RE). Mediation analysis revealed a mediating effect of aortic decay index on the relationship between changes in aortic PWV and BI. The present study provides evidence that high-intensity RE-induced aortic stiffening accelerates aortic decay and aortic decay can account for the relationship between aortic stiffening and a deteriorated surrogate marker of myocardial oxygen supply/demand balance induced by high-intensity RE.

The effect of high-intensity resistance exercise on lumbar musculature in patients with low back pain: a preliminary study

BackgroundMuscle atrophy and fatty infiltration of the lumbar extensors is associated with LBP. Exercise-based rehabilitation targets strengthening these muscles, but few studies show consistent changes in muscle quality with standard-of-care rehabilitation. The goal of this study was to assess the effect of high-intensity resistance exercise on lumbar extensor muscle size (cross sectional area) and quality (fat fraction) in individuals with low back pain (LBP).MethodsFourteen patients with LBP were recruited from a local rehabilitation clinic. Patients underwent MRI scanning before and after a standardized 10-week high-intensity machine-based, resistance exercise program. Patient pain, disability, anxiety/depression, satisfaction, strength, and range of motion was compared pre- and post-rehabilitation using analysis of covariance (covariates: age, gender). Exercise-induced changes in MRI, and patient functional outcome measures were correlated using Pearson’s correlation test.ResultsNo significant differences were found in muscle size or fatty infiltration of the lumbar extensors over the course of rehabilitation (p > 0.31). However, patients reported reduced pain (p = 0.002) and were stronger (p = 0.03) at the conclusion of the program. Improvements in muscle size and quality for both multifidus and erector spinae correlated with improvements in disability, anxiety/depression, and strength.ConclusionWhile average muscle size and fatty infiltration levels did not change with high-intensity exercise, the results suggest that a subgroup of patients who demonstrate improvements in muscle health demonstrate the largest functional improvements. Future research is needed to identify which patients are most likely to respond to this type of treatment.

Acute Cardiovascular Responses To Resistance Training With And Without Blood Flow Restriction

Recently, it has been suggested that resistance exercise (RE) can be applied for cardiovascular function, maintenance and/or for rehabilitation purposes. PURPOSE: To compare the acute effects of high intensity RE (HI), low intensity RE (LI) and low intensity RE with blood flow restriction (LI-BFR) on heart rate (HR) and blood pressure (BP) in healthy subjects. METHODS: 52 subjects ((27.3±7 years; BMI: 27.3±3.1) were assigned into three groups: High intensity (HI, 75%-1RM; n=15); low intensity (LI, 30%- 1RM; n=13); and low intensity with blood flow restriction training (LI-BFR, 30%-1RM and 30% of total vascular restriction; n=24). All participants performed 4 sets of plantar flexion in the leg press machine with 1 set of 30 repetitions following 3 sets of 15 (for LI and LI-BFR group) or 10 repetitions (HI group). Blood flow restriction was achieved using a cuff positioned on the dominant calf. The cuff was inflated at 30% of total vascular restriction of each individual (mean: 47.6 ± 19.8 mmHg). Cardiovascular variables were obtained during and after the session. RESULTS: Results indicated that HR increased significantly during the 4 exercise set for all groups (p <0.05), although the highest increases were found during the last set for the HI group (pre: 70.0±10.0 bpm; post: 81.6±11.7 bpm; p<0.001) and during the first set for the LI-BFR group (pre: 66.1±12.9 bpm; post: 73.7±15.1bpm; p<0.001). There were no significant differences in BP for any group. However, significant intergroup differences were observed in systolic BP during the first set for HI and LI-BFR groups when compared to LI group (p=0.03). HI and LI-BFR promoted significant systolic BP reductions (p<0.001) 30min post-exercise (pre: 126.1±11.7 mmHg; post: 112.3±14.0 mmHg), 45min post-exercise (pre: 126.1±11.7 mmHg; post: 113.1±10.2 mmHg) and for HI group post-15min (pre: 123.6±15.7 mmHg; post: 115.0±15.9 mmHg), post-45min (pre: 123.6±15.7 mmHg; post: 114.4±16.7 mmHg) and post-60min (pre: 123.6±15.7 mmHg; post: 113.3±14.7 mmHg). There were no significant changes (p>0.05) for diastolic BP and HR of the LI-BFR group. CONCLUSION: LI-BFR resistance training is able to generate an acute hemodynamic and cardiovascular response similar to HI and LI resistance exercise. HI and LI-BFR seem to promote a hypotensive post-exercise response.

Effects of acute high-Intensity resistance exercise on cognitive function and oxygenation in prefrontal cortex.

[Purpose]Moderate-intensity exercise is known to be the best effective intensity to enhance cognitive function, including memory and learning. However, the effects of high-intensity exercise in comparison with moderate- intensity exercise on cognitive function remain controversial. The aim of this study was to investigate the effect of high-intensity resistance exercise on cognitive function. [Methods]Thirty-six healthy female college students volunteered to participate in this study. The participants were divided into four groups: (i) control group (CON); (ii) high-intensity resistance exercise group (HIR); (iii) high-intensity aerobic exercise group (HIA); and (iv) combined moderate-intensity exercise group (MIC). Immediately prior to and after exercise, the solved number (SN) and reaction times (RT) in the Stroop test (neutral task, NT and incongruent task, IT), as well as the tissue oxygen index (TOI) in the left and right prefrontal cortex (PFC) were measured in all groups. [Results]In the NT, both HIR and MIC groups showed significant improvements in SN and RT compared with the CON group. Meanwhile, performance in the HIA group was significantly attenuated compared with that in the MIC group. In the IT, only the MIC group showed a significant increase in SN and RT compared with the CON group. Furthermore, the TOI in the PFC (left PFC in the NT, and bilaterally in the IT) was significantly lower in the HIR group compared with that in the CON group. [Conclusion]The results of this study show worse cognitive performance and decreased PFC oxygenation in high-intensity exercise compared with moderate-intensity exercise and controls. These results suggest that high-intensity exercise may not improve cognition as effectively as moderate-intensity exercise.

Acute Effect of High-Intensity Eccentric Exercise on Vascular Endothelial Function in Young Men.

Choi, Y, Akazawa, N, Zempo-Miyaki, A, Ra, S-G, Shiraki, H, Ajisaka, R, and Maeda, S. Acute effect of high-intensity eccentric exercise on vascular endothelial function in young men. J Strength Cond Res 30(8): 2279-2285, 2016-Increased central arterial stiffness is as an independent risk factor for cardiovascular disease. Evidence regarding the effects of high-intensity resistance exercise on vascular endothelial function and central arterial stiffness is conflicting. The purpose of this study was to examine the effects of acute high-intensity eccentric exercise on vascular endothelial function and central arterial stiffness. We evaluated the acute changes in endothelium-dependent flow-mediated dilation (FMD), low-flow-mediated constriction (L-FMC), and arterial stiffness after high-intensity eccentric exercise. Seven healthy, sedentary men (age, 24 ± 1 year) performed maximal eccentric elbow flexor exercise using their nondominant arm. Before and 45 minutes after eccentric exercise, carotid arterial compliance and brachial artery FMD and L-FMC in the nonexercised arm were measured. Carotid arterial compliance was significantly decreased, and β-stiffness index significantly increased after eccentric exercise. Brachial FMD was significantly reduced after eccentric exercise, whereas there was no significant difference in brachial L-FMC before and after eccentric exercise. A positive correlation was detected between change in arterial compliance and change in FMD (r = 0.779; p ≤ 0.05), and a negative correlation was detected between change in β-stiffness index and change in FMD (r = -0.891; p < 0.01) with eccentric exercise. In this study, acute high-intensity eccentric exercise increased central arterial stiffness; this increase was accompanied by a decrease in endothelial function caused by reduced endothelium-dependent vasodilation but not by a change in endothelium-dependent vasoconstriction.

High-Intensity Resistance Exercise Promotes Postexercise Hypotension Greater than Moderate Intensity and Affects Cardiac Autonomic Responses in Women Who Are Hypertensive.

The purpose of this study was to evaluate the effect of high-intensity resistance exercise (RE) sessions on blood pressure (BP), heart rate (HR), cardiac autonomic modulation, and forearm blood flow (FBF). Sixteen trained hypertensive women (n = 16, 56 ± 3 years) completed the following 3 experimental sessions: control (CS), RE at 50% (EX50%), and RE at 80% (EX80%) of 1 repetition maximum (1RM). Both EX50% and EX80% comprised a set of 10 repetitions of 10 exercises, with an interval of 90 seconds between exercises. Measurements were taken preintervention and postintervention (at 10, 30, 50, 70, and 90 minutes of recovery). Reductions in systolic/diastolic BP after exercise were greater in EX80% (largest declines, -29 ± 4/-14 ± 5 mm Hg) than EX50% (largest declines, -18 ± 6/-8 ± 5 mm Hg, p ≤ 0.05). Heart rate and cardiac sympathovagal balance (LF/HF) increased more in relation to pre-exercise values in EX80% than EX50% (largest increases 96 ± 3 vs. 90 ± 4 b·min, LF/HF = 1.77 ± 0.25 vs. 1.40 ± 0.20, respectively, p ≤ 0.05). Increases in FBF and hyperemia was also higher in EX80% than EX50% compared with pre-exercise (4.97 ± 0.28 vs. 4.36 ± 0.27 ml·min·100 ml and 5.90 ± 0.20 vs. 5.38 ± 0.25 ml·min·100 ml; p ≤ 0.05, respectively). These results suggest that RE of higher intensity promoted greater postexercise hypotension accompanied by greater increases in FBF, vasodilator response, HR, and cardiac sympathovagal balance.

High‐intensity exercise promotes postexercise hypotension greater than moderate intensity in elderly hypertensive individuals

To evaluate the effects of high-intensity resistance exercise on postexercise hypotension (PEH) and forearm vascular resistance (FVR) in the hypertensive elderly. The study was conducted with ten hypertensive elderly individuals (65 ± 3 years, 28·7 ± 3 kg m(-2)). They were subjected to three experimental sessions: control session (SC), exercise 50% (S50%) and 80% (S80%) of 1RM. For each session, subjects were evaluated pre-and postintervention. In the preintervention, the blood pressure (BP) and FVR were measured after 10 min of rest. Thereafter, they were taken to the gym to perform the exercise sessions or remained at rest in each of the equipment during the same time. Both S50% and S80% were composed of a set of ten repetitions of ten exercises, with an interval of 90 s between exercises. Subsequently, the FVR and BP measurements were again performed at 10, 30, 50, 70 and 90 min of recovery (postintervention). The PEH was greater in S80% compared with S50%, with the lower value of BP being found at 90 min of recovery for the two sessions (systolic BP: 115 ± 3,0 mmHg versus 124 ± 5 mmHg; diastolic BP: 75 ± 5 mmHg versus 86 ± 3 mmHg and mean BP: 87 ± 3 mmHg versus 95 ± 4 mmHg, respectively). Concomitantly, the FVR also decreased significantly in both sessions, this reduction being more evident in S80% (P<0·05). High-intensity resistance exercise was effective in promoting PEH, this phenomenon being accompanied by a reduction in FVR within the first minute of recovery in the hypertensive elderly.

The effects of high-intensity resistance exercise on the blood lipid profile and liver function in hypercholesterolemic hamsters

It is well established that atherogenic dyslipidemia, characterized by high levels of triglycerides (TG), total cholesterol (TC), and low-density lipoprotein (LDL) cholesterol and low levels of high-density lipoprotein (HDL) cholesterol, constitutes important risk factors for cardiovascular disease. Regular exercise has been associated with a reduced risk for metabolic diseases. However, studies supporting the concept that resistance exercise is a modifier of blood lipid parameters are often contradictory. The aim of this study was to investigate the effects of high-intensity resistance exercise on the serum levels of TG, TC, HDL and non-HDL cholesterol, glucose, and the liver function enzymes alanine aminotransferase (ALT, EC 2.6.1.2) and aspartate aminotransferase (AST, EC 2.6.1.1) in golden Syrian hamsters (Mesocricetus auratus (Waterhouse, 1839)) fed a hypercholesterolemic diet. Sedentary groups (S) and exercise groups (E) were fed a standard diet (SS and ES) or a cholesterol-enriched diet (standard plus 1% cholesterol, SC and EC). Resistance exercise was performed by jumps in the water, carrying a load strapped to the chest, representing 10 maximum repetitions (10 RM, 30 s rest, five days per week for five weeks). Mean blood sample comparisons were made by ANOVA + Tukey or ANOVA + Kruskal-Wallis tests (p < 0.05) to compare parametric and nonparametric samples, respectively. There were no differences in blood lipids between the standard diet groups (SS and ES) (p > 0.05). However, the EC group increased the glucose, non-HDL, and TC levels in comparison with the ES group. Moreover, the EC group increased the TG levels versus the SC group (p < 0.05). In addition, the ALT levels were increased only by diet treatment. These findings indicated that high-intensity resistance exercise contributed to dyslipidemia in hamsters fed a hypercholesterolemic diet, whereas liver function enzymes did not differ in regards to the exercise protocol.