High-intensity Resistance Exercise Research Articles

ELECTROLYTE CHANGES RELATED TO MUSCLE PAIN AFTER RESISTANCE EXERCISES

ABSTRACT Introduction Resistance exercises (RE) performed at high intensity cause an inflammatory response and electrolyte abnormalities in blood plasma. Objectives To study the plasma electrolyte changes resulting from a high-intensity session of RE in untrained volunteers, and to correlate these with delayed onset muscle soreness (DOMS). Methods Twenty volunteers, aged 26.9 (±4.4) years, underwent an RE session. The workout (leg extension, squat and leg press) consisted of four sets of 10 maximum repetitions. Electrolytes (Na+, K+, Ca2+ e Mg2+) were evaluated before the training (baseline), immediately (0 min), and 30 minutes after the RE. The DOMS was assessed 24 hours after the sessions. Results The Na+ increased immediately after the RE and returned to normal after 30 min (p<0.001). After 30 min, K+ increased compared to baseline levels and immediately after the RE (p<0.001). Ca2+ and Mg2+ levels did not change throughout the study. Changes in Na+ and K+ levels were correlated immediately (r=-0.511; p=0.021) and 30 min (r=-0.455; p=0.049) after RE. Plasma concentrations of Na+ 0 min were correlated (r=-0.520; p=0.018) with the DOMS. Conclusion High-intensity RE in untrained volunteers leads to changes in plasma concentrations of Na+ and K+. Na+ concentrations immediately after RE were related to DOMS; individuals that presented smaller alterations in this electrolyte reported more muscular pain. Level of evidence II; Diagnostic Studies - Development of diagnostic criteria on consecutive patients (with universally applied reference “gold” standard).

Randomized clinical trial on the effect of a supervised exercise program on quality of life, fatigue, and fitness following esophageal cancer treatment (PERFECT study).

12055 Background: Patients with potentially curable esophageal cancer are often treated with chemoradiotherapy followed by surgery. This treatment might have a negative impact on physical fitness, fatigue and quality of life (QoL). In patients with other types of cancer, evidence suggests that physical exercise reduces treatment related side effects. We investigated whether a supervised exercise program also beneficially affects QoL, fatigue and cardiorespiratory fitness (CRF) in patients after treatment for esophageal cancer. Methods: The multicenter PERFECT study randomly assigned patients in the first year after esophagectomy to an exercise intervention (EX) or usual care (UC) group. EX patients participated in a 12-week moderate to high intensity aerobic and resistance exercise program supervised by a physiotherapist. UC patients were advised to maintain their physical activity levels. Attendance and compliance with the exercise intervention protocol were retrieved from exercise logs. QoL (primary outcome, EORTC-QLQ-30, range 0-100), fatigue (MFI-20, range 4-20) and CRF (cardiopulmonary exercise testing) were assessed at baseline and after 12 weeks (post-intervention). The outcomes were analyzed as between-group differences using either linear mixed effects models or ANCOVA adjusted for baseline and stratification factors (i.e. sex, time since surgery, center), according to the intention-to-treat principle. Results: A total of 120 patients (age 64±8) were included and randomized to EX (n = 61) or UC (n = 59). Patients in the EX group participated in 96% (IQR:92-100%) of the supervised exercise sessions and compliance with all parts of the exercise program was high ( > 90%). Post-intervention, global QoL was not statistically different between groups, but significant (p < 0.05) beneficial EX effects were found for QoL-Summary scores (between-group difference 3.5, 95% CI 0.2;6.8) and QoL-role functioning (9.4, 1.3;17.5). Physical fatigue wat non-significantly lower in the EX group (-1.2; -2.6;0.1, p = 0.08). CRF was significantly higher (VO2peak (1.8 mL/min/kg, 0.6;3.0) following the EX intervention. Conclusions: Patients were well capable to complete an intensive supervised exercise program after esophageal cancer treatment, which led to small but significant improvements in several aspects of QoL and cardiorespiratory fitness. Our results suggest that supervised exercise is a beneficial addition to routine care of patients with esophageal cancer. Clinical trial information: NTR5045 .

Moderate- to high intensity aerobic and resistance exercise reduces peripheral blood regulatory cell populations in older adults with rheumatoid arthritis

ObjectiveExercise can improve immune health and is beneficial for physical function in patients with rheumatoid arthritis (RA), but the immunological mechanisms are largely unknown. We evaluated the effect of moderate- to high intensity exercise with person-centred guidance on cells of the immune system, with focus on regulatory cell populations, in older adults with RA.MethodsOlder adults (≥65 years) with RA were randomized to either 20-weeks of moderate – to high intensity aerobic and resistance exercise (n = 24) or to an active control group performing home-based exercise of light intensity (n = 25). Aerobic capacity, muscle strength, DAS28 and CRP were evaluated. Blood samples were collected at baseline and after 20 weeks. The frequency of immune cells defined as adaptive regulatory populations, CD4 + Foxp3 + CD25 + CD127- T regulatory cells (Tregs) and CD19 + CD24hiCD38hi B regulatory cells (Bregs) as well as HLA-DR−/lowCD33 + CD11b + myeloid derived suppressor cells (MDSCs), were assessed using flow cytometry.ResultsAfter 20 weeks of moderate- to high intensity exercise, aerobic capacity and muscle strength were significantly improved but there were no significant changes in Disease Activity Score 28 (DAS28) or CRP. The frequency of Tregs and Bregs decreased significantly in the intervention group, but not in the active control group. The exercise intervention had no effect on MDSCs. The reduction in regulatory T cells in the intervention group was most pronounced in the female patients.ConclusionModerate- to high intensity exercise in older adults with RA led to a decreased proportion of Tregs and Bregs, but that was not associated with increased disease activity or increased inflammation.Trial registrationImproved Ability to Cope With Everyday Life Through a Person-centered Training Program in Elderly Patients With Rheumatoid Arthritis - PEP-walk Study, NCT02397798. Registered at ClinicalTrials.gov March 19, 2015.

Tribulus Terrestris may decrease muscle damage markers following a high-intensity resistance exercise: A pilot study.

The purpose of this study was to investigate the effect of two weeks of Tribulus Terrestris (TT) on the responses of Interleukin-6 (IL-6), high sensitivity C-reactive protein (hs-CRP), and enzymes creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) following a single session of resistance exercise (RE). Eighteen healthy non-athlete males (age: 22.44 ± 2.54 years, BMI: 26.15 ± 1.62 kg/m2) participated in this study and were divided randomly into two 9-person groups of supplementation or placebo. The participants consumed two 250-mg capsules of TT or placebo (maltodextrin) per day and performed six REs with the intensity 80, 85, and 90% of 1RM in three circles at the day after the end of supplementation period. Blood samples were collected before the initiation of supplementation, and before and after the RE session. Total changes of IL-6 (p<0.001) and LDH (p=0.005) were significant in both groups. Bonferroni post hoc test showed that increased values of IL-6 and CPK in both groups were significant after exercise compared with pre-exercise and baseline (p<0.001). There were no significant differences in relation to within- and between-group changes in hs-CRP (p>0.05). Moreover, differences between the groups regarding post-exercise IL-6 and CPK were not significant (p>0.05). However, post-exercise LDH in supplementation group were lower than placebo group (p=0.015). In conclusion, short-term supplementation with TT has no effect on IL-6 and hs-CRP, but may be effective on the reduction of muscle damage enzymes CPK and LDH following high-intensity circuit RE.

Effect of different exercise training intensities on musculoskeletal and neuropathic pain in inactive individuals with type 2 diabetes – Preliminary randomised controlled trial

AimsPeople with type 2 diabetes (T2D) have a greater prevalence of musculoskeletal and neuropathic pain. This exploratory analysis investigated whether exercise of different intensities leads to changes in self-reported musculoskeletal pain or symptoms of diabetic neuropathy in inactive individuals with type 2 diabetes. MethodsThirty-two inactive adults with T2D (59% male, mean age 58.7 ± 9.1yrs, median HbA1c 7.8%) were randomised to usual care (CON), supervised combined aerobic and resistance moderate-intensity continuous training (C-MICT), or supervised combined high-intensity interval training (C-HIIT). At baseline and 8-weeks, musculoskeletal and neuropathic pain were evaluated using a modified Nordic Musculoskeletal Questionnaire and the Neuropathy Total Symptom Score-6 respectively. Quantitative sensory testing was used to determine thermal, mechanical and vibration detection thresholds, as well as pain pressure thresholds. Adverse events were recorded throughout the intervention. ResultsCompared to CON, reduction in musculoskeletal pain intensity was significantly greater for C-HIIT (MD −5.4, 95% CI [−10.6 to −0.2], p = 0.04) and non-significantly greater for C-MICT (MD −5.9 [−12.4 to 0.7], p = 0.08). Changes in neuropathy symptoms were not different between C-HIIT and CON (MD 1.0 [−0.9 to 2.8], p = 0.31), or C-MICT and CON (MD 0.2 [−3.1 to 3.6], p = 0.89). No differences in sensory function were observed between groups. Similar rates of adverse events were seen in both exercise interventions (19 C-HIIT; 17 C-MICT), all but one of which were mild. ConclusionsPreliminary data suggests 8-weeks of high-intensity combined aerobic and resistance exercise may be safely prescribed for inactive individuals with T2D and may reduce musculoskeletal pain but not neuropathic symptoms.Trial Registration:ACTRN12615000475549.

Acute Psychological Effects of Resistance Exercise in Men With Symptoms of Muscle Dysmorphia: A Pilot Study.

SantaBarbara, NJ, Nosrat, S, Whitworth, JW, Ciccolo, JT. acute psychological effects of resistance exercise in men with symptoms of muscle dysmorphia: A pilot study. J Strength Cond Res 37(2): 277-283, 2023-This study tested the acute psychological effects of resistance exercise in men with symptoms of muscle dysmorphia. Twenty-one men completed 4 on-site sessions including a single session of moderate- (70% of 10 repetition maximum [RM]) and high- (100% of 10RM) intensity resistance exercise in a counter balanced order separated by at least 48 hours. State body image, perceived muscle size, exercise enjoyment, and ratings of perceived exertion (RPE) were assessed before, during, and after each session, and statistical significance was set a priori at p < 0.05. State body image significantly improve from pre to post during both sessions ( p < 0.01), with greater effect sizes seen for the high- ( d = 0.57) compared with the moderate- ( d = 0.39) intensity session. Perceived muscle size improved from pre to post during the high-intensity only ( p < 0.01, d = 0.66), and subjects enjoyed the high-intensity session significantly more than the moderate-intensity session ( p = 0.01), despite significantly higher RPE at each timepoint ( p < 0.01). Results contend with previous findings that show more positive psychological effects of moderate- compared with high-intensity resistance exercise. Education and client observation are essential to be aware of the potential for muscle dysmorphia. In instances where muscle dysmorphia is suspected, referral to qualified mental health professionals is recommended.

Concurrent high-intensity aerobic and resistance exercise modulates systemic release of alarmins (HMGB1, S100A8/A9, HSP70) and inflammatory biomarkers in healthy young men: a pilot study

BackgroundIntense exercise is a systemic stressor associated with the release of “danger” molecules – alarmins, by damaged or dying cells into systemic circulation to evoke a sterile inflammatory response. Compared with research in clinical diseases, physiological responses of alarmins to exercise and training are not well studied. Short-term responses to exercise and training using a panel of alarmins – HMGB1, S100A8/A9, HSP70 and sRAGE may reveal unique aspects of stress responses to strenuous exercise, with important ramifications when prescribing exercise to generally healthy adults.MethodsA 3-week, high-intensity training program was performed by healthy young men (N = 7). Concurrent aerobic and resistance exercises were performed on 3 consecutive days each week. Blood and saliva were collected before (Pre), immediately after (Post), and 30 min (30 min) after exercise each week, and 24 h after the final exercise session in week 3 (24 h).ResultsPlasma HMGB1, S100A8/A9 and HSP70 increased from Pre to Post (P < 0.05), although at different timepoints during the study, and displayed different kinetics from IL-10, IL-8 and IFN-γ, suggesting unique mechanisms involved in modulating their release and clearance. CD14+CD16− monocytes increased from Pre to Post across 3 weeks; CD14+CD16+ monocytes increased from Pre to Post in week 2 and 3 (P < 0.05). ΔHMGB1 and ΔHSP70 correlated positively with ΔMCP-1 during 3 weeks of training. As well, ΔHMGB1 correlated positively with CD14+CD16− monocytes, suggesting higher alarmin release after strenuous exercise may involve increase in circulating monocytes.ConclusionsPerturbations in systemic alarmins are novel biological signatures for assessing the inflammatory milieu of healthy adults during high-intensity exercise.

Blood Flow Restriction Training Applied With High-Intensity Exercise Does Not Improve Quadriceps Muscle Function After Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

Background: A major goal of rehabilitation after anterior cruciate ligament reconstruction (ACLR) is restoring quadriceps muscle strength. Unfortunately, current rehabilitation paradigms fall short of this goal, such that substantial quadriceps muscle strength deficits can limit return to play and increase the risk of recurrent injuries. Blood flow restriction training (BFRT) involves the obstruction of venous return to working muscles during exercise and may lead to better recovery of quadriceps muscle strength after ACLR. Purpose: To examine the efficacy of BFRT with high-intensity exercise on the recovery of quadriceps muscle function in patients undergoing ACLR. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: A total of 34 patients (19 female, 15 male; mean age, 16.5 ± 2.7 years; mean height, 169.0 ± 19.7 cm; mean weight, 73.2 ± 17.7 kg) scheduled to undergo ACLR were randomly assigned to 1 of 4 groups: concentric (n = 8), eccentric (n = 8), concentric with BFRT (n = 9), and eccentric with BFRT (n = 9). The exercise component of the intervention consisted of patients performing a single-leg isokinetic leg press, at an intensity of 70% of the patients’ 1-repetition maximum during either the concentric or eccentric action, for 4 sets of 10 repetitions 2 times per week for 8 weeks beginning at 10 weeks postoperatively. Patients randomized to the BFRT groups performed the leg-press exercise with a cuff applied to the thigh, set to a limb occlusion pressure of 80%. Isometric and isokinetic (60 deg/s) quadriceps peak torque, quadriceps muscle activation, and rectus femoris muscle volume were assessed before ACLR, after BFRT, and at the time that patients returned to activity and were converted to the change in values from baseline for analysis. Also, 1-way analyses of covariance were used to compare the change in values for each dependent variable between groups after BFRT and at return to activity (P ≤ .05). Results: No significant differences were found between groups for any outcome measures at either time point (P > .05). Conclusion: An 8-week BFRT plus high-intensity exercise intervention did not significantly improve quadriceps muscle strength, activation, or volume. On the basis of our findings, the use of BFRT in conjunction with high-intensity resistance exercise in patients undergoing ACLR to improve quadriceps muscle function may not be warranted. Registration: NCT03141801 (ClinicalTrials.gov identifier)

Low-level laser therapy prevents muscle apoptosis induced by a high-intensity resistance exercise in a dose-dependent manner.

Low-level laser therapy prevents muscle apoptosis induced by a high-intensity resistance exercise in a dose-dependent manner.

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.

High Intensity Resistance Exercise Training to Improve Body Composition and Strength in Older Men With Osteosarcopenia. Results of the Randomized Controlled Franconian Osteopenia and Sarcopenia Trial (FrOST).

Considerably decreased muscle mass and function are subsumed under “sarcopenia,” a geriatric syndrome. Dedicated exercise programs maintain muscle mass and function; however, due to the limited enthusiasm of older adults to exercise, it is important to generate low-threshold interventions for this vulnerable cohort. Thus, the primary aim of this study was to determine the effect of low volume/high intensity resistance exercise training (HIT-RT) combined with protein supplementation on body composition and strength in older men with sarcopenia and osteopenia (osteosarcopenia). Forty-three community-dwelling (cdw) older men (78 ± 4 years) with osteosarcopenia were randomly allocated to a consistently supervised HIT-RT (n = 21) or an inactive control group (CG, n = 22). HIT-RT scheduled a single set protocol with high intensity and effort applied twice a week for 36 weeks so far. Both groups were supplemented with Vit-D (800 IE/d), calcium (1,000 mg/d) and whey-protein (CG: 1.2 vs. HIT-RT: 1.5–1.7 g/kg/d). Study endpoints were body composition (dual-energy x-ray absorptiometry) and maximum isokinetic hip/leg-extensor strength (MIES) by leg-press. After 36 weeks, one participant who developed prostate cancer after inclusion in the study (HIT-RT) and two participants who lost interest (CG, HIT-RT) quit the study. Attendance rate for HIT-RT averaged 93 ± 5%. Total and thigh lean body mass (LBM) significantly (p < 0.001) increased in the HIT-RT and was maintained in the CG (p = 0.46 and 0.37). Differences between the groups for changes of total and thigh LBM were pronounced (p < 0.001; SMD d′ = 1.17 and 1.20). Total and abdominal body fat percentage decreased significantly in the HIT-RT (p < 0.001) and increased in the CG (p = 0.039 and p = 0.097). Intergroup differences were significant (p < 0.001; SMD: d′ = 1.35 and 1.28). Finally, MIES was maintained in the CG (p = 0.860), and improved significantly (p < 0.001) in the HIT-RT. Differences between the groups were significant (p < 0.001, SMD: d′ = 2.41). No adverse effects of the intervention were observed. In summary, the HIT-RT/protein protocol significantly affected body composition and strength in cdw men 72 years+ with osteosarcopenia. In the absence of negative side effects, the intervention was feasible, attractive and time effective. Thus, we conclude that supervised HIT-RT might be an exercise option for older men.

Low-level laser therapy prevents muscle oxidative stress in rats subjected to high-intensity resistance exercise in a dose-dependent manner.

High-intensity resistance exercise (RE) increases oxidative stress leading to deleterious effects on muscle performance and recovery. The aim of this study was to assess the effect of applying low-level laser therapy (LLLT) prior to a RE session on muscle oxidative stress and to determine the possible influence of the dosimetric parameters. Female Wistar rats were assigned to non-LLLT (Ctr: non-exercised control; RNI: RE) or LLLT groups subjected to RE (radiant energy: 4J, 8J, and 12J, respectively). RE consisted of four maximum load climbs. An 830-nm DMC Lase Photon III was used to irradiate three points in gastrocnemius muscles (two limbs) before exercise. Animals were euthanized after 60min after the end of the exercise, and muscle tissue was removed for analysis of oxidative stress markers. All doses resulted in the prevention of increased lipoperoxidation; however, LLLT prevented protein oxidation only in rats that were pretreated with 8J and 12J of energy by LLLT. RE and LLLT did not change catalase activity. However, RE resulted in lower superoxide dismutase activity, and the opposite was observed in the LLLT group. These data indicate that LLLT prior to RE can prevent muscle oxidative stress. This study is the first to evaluate the impact of dosimetric LLLT parameters on the oxidative stress induced by RE, wherein both 8J and 12J of energy afforded significant protection.

Hippocampal plasticity underpins long-term cognitive gains from resistance exercise in MCI.

Dementia affects 47 million individuals worldwide, and assuming the status quo is projected to rise to 150 million by 2050. Prevention of age-related cognitive impairment in older persons with lifestyle interventions continues to garner evidence but whether this can combat underlying neurodegeneration is unknown. The Study of Mental Activity and Resistance Training (SMART) trial has previously reported within-training findings; the aim of this study was to investigate the long-term neurostructural and cognitive impact of resistance exercise in Mild Cognitive Impairment (MCI). For the first time we show that hippocampal subareas particularly susceptible to volume loss in Alzheimer's disease (AD) are protected by resistance exercise for up to one year after training. One hundred MCI participants were randomised to one of four training groups: (1) Combined high intensity progressive resistance and computerised cognitive training (PRT+CCT), (2) PRT+Sham CCT, (3) CCT+Sham PRT, (4) Sham physical+sham cognitive training (SHAM+SHAM). Physical, neuropsychological and MRI assessments were carried out at baseline, 6 months (directly after training) and 18 months from baseline (12 months after intervention cessation). Here we report neuro-structural and functional changes over the 18-month trial period and the association with global cognitive and executive function measures. PRT but not CCT or PRT+CCT led to global long-term cognitive improvements above SHAM intervention at 18-month follow-up. Furthermore, hippocampal subfields susceptible to atrophy in AD were protected by PRT revealing an elimination of long-term atrophy in the left subiculum, and attenuation of atrophy in left CA1 and dentate gyrus when compared to SHAM+SHAM (p=0.023, p=0.020 and p=0.027). These neuroprotective effects mediated a significant portion of long-term cognitive benefits. By contrast, within-training posterior cingulate plasticity decayed after training cessation and was unrelated to long term cognitive benefits. Neither general physical activity levels nor fitness change over the 18-month period mediated hippocampal trajectory, demonstrating that enduring hippocampal subfield plasticity is not a simple reflection of post-training changes in fitness or physical activity participation. Notably, resting-state fMRI analysis revealed that both the hippocampus and posterior cingulate participate in a functional network that continued to be upregulated following intervention cessation. Multiple structural mechanisms may contribute to the long-term global cognitive benefit of resistance exercise, developing along different time courses but functionally linked. For the first time we show that 6 months of high intensity resistance exercise is capable of not only promoting better cognition in those with MCI, but also protecting AD-vulnerable hippocampal subfields from degeneration for at least 12 months post-intervention. These findings emphasise the therapeutic potential of resistance exercise; however, future work will need to establish just how long-lived these outcomes are and whether they are sufficient to delay dementia.

Age-dependent stress response DNA demethylation and gene upregulation accompany nuclear and skeletal muscle remodeling following acute resistance-type exercise in rats.

Efficacy of high-intensity resistance exercise becomes progressively compromised with aging. Previously, to investigate this, we developed a rodent model of high-intensity training consisting of stretch-shortening contractions (SSCs) and determined that following one month of training, young rats exhibit a robust stress response and 20% performance increase, whereas old rats display a muted stress response and 30% performance decrease. Whether these age-specific responses occur early in training and constitute primary factors in adaptation/maladaptation was not addressed. The aim of the present study was to characterize performance, remodeling, and stress response transcriptional profile 6–120 h following acute SSC exposure. For young rats, the stress response pathway was highly regulated (≥20 differentially expressed genes at each time point) and was accompanied by robust DNA demethylation, tissue remodeling, and isometric torque recovery. For old rats, a muted transcriptional profile (13 and 2 differentially expressed genes at 6 and 120 h, respectively) coincided with deficiencies in demethylation, muscle remodeling, and torque recovery. These findings occurred in the context of heightened chronic levels of stress response gene expression with aging. This demonstrates that age-related constitutive elevations in stress response gene expression was accompanied by diminished SSC-induced responsiveness in epigenomic regulation and tissue remodeling.

Acute Capsaicin Supplementation Improved Resistance Exercise Performance Performed After a High-Intensity Intermittent Running in Resistance-Trained Men.

de Freitas, MC, Cholewa, JM, Panissa, VLG, Toloi, GG, Netto, HC, Zanini de Freitas, C, Freire, RV, Lira, FS, and Rossi, FE. Acute capsaicin supplementation improved resistance exercise performance performed after a high-intensity intermittent running in resistance-trained men. J Strength Cond Res 36(1): 130-134, 2022-We sought to investigate the acute effects of capsaicin supplementation on the rate of perceived exertion (RPE) and heart rate during high-intensity intermittent exercise (HIIE) and resistance exercise performance executed after HIIE in resistance-trained men. Eleven resistance-trained men completed 2 randomized, double-blind trials: capsaicin condition or a placebo condition. The concurrent exercise session was composed of a 5-km intermittent run (1:1 effort and passive recovery ratio) and subsequent resistance exercise (4 × 70% of 1RM until muscle failure in the half-squat exercise). Heart rate was recorded during HIIE and after the protocol RPE (0-10 scale) was accessed. The resistance exercise performance was analyzed by the maximum number of repetitions performed for each set and the total volume (repetitions × weight lifted). During HIIE, the RPE (capsaicin = 7 ± 1 vs. placebo = 8 ± 1 points, t = -3.674, p = 0.005) and mean heart rate (capsaicin = 153 ± 13 vs. placebo = 158 ± 12 bpm, t = -2.292, p = 0.048) were significantly lower in the capsaicin compared with placebo condition. For subsequent resistance exercise, there was a significant decrease in volume across time (F = 19.889, p < 0.001, η2= 0.69) with maximal number of repetitions performed in capsaicin than placebo condition (2,077.6 ± 465.2 kg vs. 1,838.9 ± 624.1 kg, p = 0.028, d = 0.43), but the condition vs. set was not significant (F = 0.582, p = 0.632, η2= 0.06). Acute capsaicin supplementation induced a lower mean heart rate and RPE during HIIE and improved subsequent resistance exercise performance in resistance-trained men.

Feasibility of Resistance Exercise for Posttraumatic Stress and Anxiety Symptoms: A Randomized Controlled Pilot Study.

Emerging evidence suggests that exercise may beneficially affect posttraumatic stress symptoms (PTSS), but few randomized trials exist. Additionally, the effects of resistance exercise (i.e., weight lifting or strength training) on PTSS have not been thoroughly examined. This study aimed to explore the feasibility of a brief high-intensity resistance exercise intervention for PTSS and related issues, such as anxiety, sleep, alcohol use, and depression, in non-treatment-seeking adults who screened positive for posttraumatic stress disorder (PTSD) and anxiety. The sample included 30 non-treatment-seeking, urban-dwelling adults (M age = 29.10 years, SD = 7.38; 73.3% female) who screened positive for PTSD and anxiety and were randomly assigned to either a 3-week resistance exercise intervention or a time-matched contact control condition. The results suggest the intervention was feasible, with 80.0% (n = 24) of participants completing the study, 88.9% of the resistance exercise sessions attended, and no adverse effects reported. Additionally, resistance exercise had large beneficial effects on symptoms of avoidance, d = 1.26, 95% CI [0.39, 2.14]; and hyperarousal, d = 0.90, 95% CI [0.06, 1.74], relative to the control condition. Resistance exercise also produced large improvements concerning sleep quality, d = 1.31, 95% CI [0.41, 2.21], and hazardous alcohol use, d = 0.99, 95% CI [0.13, 1.86], compared to the control condition. Overall, the findings suggest that 3 weeks of high-intensity resistance exercise is a feasible intervention for PTSS reduction in non-treatment-seeking adults who screen positive for PTSD and anxiety; additional research is needed to verify these preliminary findings.

The Effects of Leucine-Enriched Branched-Chain Amino Acid Supplementation on Recovery After High-Intensity Resistance Exercise.

Of the 3 branched-chain amino acids (BCAA), leucine has arguably received the most attribution for the role of BCAA supplementation in alleviating symptoms of exercise-induced muscle damage and facilitation of acute performance recovery. To examine whether enrichment of a standard BCAA supplement with additional leucine or a standalone leucine (LEU) supplement differentially affects exercise-induced muscle damage and performance recovery compared with a standard BCAA supplement. A total of 22 recreationally active male and female subjects were recruited and assigned to consume a BCAA, leucine-enriched BCAA (LBCAA), or LEU supplement for 11 d. On the eighth day, subjects performed eccentric-based resistance exercise (ECRE). Lower-body mean average and peak power, plasma creatine kinase, soreness, and pain threshold were measured before and 24, 48, and 72h after ECRE. LEU showed decreased mean average power (P = .02) and mean peak power (P = .01) from baseline to 48h post-ECRE, whereas LBCAA and BCAA only trended toward a reduction at 24 hours post-ECRE. At 48h post-ECRE, BCAA showed greater recovery of mean peak power than LEU (P = .04). At 24h post-ECRE, LEU demonstrated a greater increase in plasma creatine kinase from baseline than BCAA (P = .04). Area under the curve for creatine kinase was greater in LEU than BCAA (P = .02), whereas BCAA and LBCAA did not differ. Only LEU demonstrated increased soreness during rest and under muscular tension at 24 and 48 h post-ECRE (P < .05). LBCAA failed to afford any advantages over a standard BCAA supplement for postexercise muscle recovery, whereas a LEU supplement was comparatively ineffective.

Blood flow restriction in human skeletal muscle during rest periods after high-load resistance training down-regulates miR-206 and induces Pax7

BackgroudBlood flow restriction (BFR) with low-intensity resistance training has been shown to result in hypertrophy of skeletal muscle. In this study, we tested the hypothesis that BFR during the rest periods between acute, high-intensity resistance exercise sessions (70% of 1 repetition maximum, 7 sets with 10 repetitions) enhances the effects of the resistance training. MethodsA total of 7 healthy young men performed squats, and between sets BFR was carried out on one leg while the other leg served as a control. Because BFR was applied during rest periods, even severe occlusion pressure (approximately 230 mmHg), which almost completely blocked blood flow, was well-tolerated by the participants. Five muscle-specific microRNAs were measured from the biopsy samples, which were taken 2 h after the acute training. ResultsDoppler data showed that the pattern of blood flow recovery changed significantly between the first and last BFR. microRNA-206 levels significantly decreased in the BFR leg compared to the control. The mRNA levels of RAC-β serine/threonine-protein kinase v22, nuclear respiratory factor 1, vascular endothelial growth factor, lupus Ku autoantigen protein p70 genes (p < 0.05), and paired box 7 (p < 0.01) increased in the BFR leg. The protein levels of paired box 7, nuclear respiratory factor 1, and peroxisome proliferator-activated receptor γ coactivator 1α did not differ between the BFR leg and the control leg. ConclusionBFR, during the rest periods of high-load resistance training, could lead to mRNA elevation of those proteins that regulate angiogenesis, mitochondrial biogenesis, and muscle hypertrophy and repair. However, BFR also can cause DNA damage, judging from the increase in mRNA levels of lupus Ku autoantigen protein p70.

A Comparison between the Recovery Responses Following an Eccentrically Loaded Bench Press Protocol Vs. Regular Loading in Highly Trained Men.

The purpose of this study was to compare the physiological responses of a single bout of an eccentric accentuated bench press protocol (120% of 1RM in the eccentric phase/80% in the concentric phase; [120/80]) versus a regular high-intensity exercise protocol (80%/80%; [80/80]) in resistance-trained men. Eleven men (age = 25.6 ± 3.9 y; body mass = 84.6 ± 11.2 kg; body height = 176.4 ± 3.9 cm) with 6.3 ± 3.4 y of resistance training experience performed each protocol in counterbalanced, randomized order. Isometric, isokinetic and ballistic tests were performed at the bench press (IBPF, ISOK and BTP, respectively) at baseline (BL), 15-min (15P), 24-h (24P), and 48-h (48P) post-exercise for each testing session. In addition, muscle thickness of the pectoralis major (PecMT) was measured at the same timepoints via ultrasound. Significantly greater reductions in BTP (p < 0.001), peak force during both ISOK (p = 0.005) and IBPF (p = 0.006) at 15P were detected in 120/80 compared to 80/80. BTP was still significantly (p = 0.009) impaired at 48P following the 120/80 protocol, while no differences were noted following 80/80. PecMt was significantly elevated following both 120/80 and 80/80 (p < 0.05) at 15P, but significant differences between the trials were present at 15P and 24P (p = 0.005 and p = 0.008, respectively). Results indicated that heavy eccentric loading during the bench press exercise caused greater performance deficits than a bout of traditionally loaded high intensity resistance exercise. Power performance appears to be more influenced by the 120/80 protocol than isometric peak force. Eccentrically loaded exercise sessions should be separated by at least 48 hours to obtain a complete recovery of the initial muscle morphology and performance.

Effects of a 12-Week Resistance Training Program on Arterial Stiffness: A Randomized Controlled Trial.

Werner, TJ, Pellinger, TK, Rosette, VD, and Ortlip, AT. Effects of a 12-week resistance training program on arterial stiffness: a randomized controlled trial. J Strength Cond Res 35(12): 3281-3287, 2021-Arterial stiffness is an indicator of disease and is an independent predictor of cardiovascular events. Some reports indicate that resistance training increases indices of arterial stiffness, whereas others report no association. This study sought to determine the association between 2 common resistance training models and indices of arterial stiffness. We recruited 30 male, untrained subjects (18-30 years) and randomized them into 1 of 3 groups: control (CON, n = 10), high-intensity resistance exercise (HI, n = 10), and high-volume resistance exercise (HV, n = 10). Subjects randomized to the resistance training groups were required to perform whole-body strength training exercises 3-5 days a week for 12 weeks. The exercise regimen consisted of 2-3 sets of 3-8 repetitions (80-90% of 1 repetition maximum [1RM]) for the HI group and 3-4 sets of 10-15 repetitions (50-70% of 1RM) for the HV group. Anthropometry, carotid artery diameters, peripheral and central blood pressure, and maximal dynamic strength were measured before and after the 12-week study period. Subjects were instructed to maintain their normal diet and avoid aerobic exercise during the study. After the intervention, both the HI and HV groups increased their maximal strength on the back squat, bench press, and seated row (all p < 0.05). However, there were no changes in arterial stiffness indices between the groups. Using a randomized controlled trial with validated measurements of arterial stiffness, chronic resistance training does not appear to influence central arterial stiffness, regardless of training volume and load.