Does external pneumatic compression treatment between bouts of overreaching resistance training sessions exert differential effects on molecular signaling and performance-related variables compared to passive recovery? An exploratory study

Effects of different intermittent pneumatic compression stimuli on ankle dorsiflexion range of motion

Despite substantial evidence of the effectiveness of intermittent pneumatic compression (IPC) treatments for range of motion (ROM) improvement, little evidence is available regarding how different IPC stimuli affect ankle dorsiflexion (DF) ROM. This study aimed to investigate the effects of different IPC stimuli on the ankle DF ROM. Fourteen, university intermittent team sport male athletes (age: 21 ± 1 year, height: 1.74 ± 0.05 m, body mass: 70.9 ± 7.7 kg, body fat percentage: 14.2 ± 3.6%, body mass index: 23.5 ± 2.5 kg/m²; mean ± standard deviation) completed four experimental trials in a random order: 1) no compression with wearing IPC devices (SHAM), 2) the sequential compression at approximately 80 mmHg (SQUEE80), 3) the uniform compression at approximately 80 mmHg (BOOST80), and 4) the uniform compression at approximately 135 mmHg (BOOST135). For the experimental trials, the participants were initially at rest for 10 min and then assigned to either a 30-min SHAM, SQUEE80, BOOST80, or BOOST135. Participants rested for 20 min after IPC treatment. The Weight-Bearing Lunge Test (WBLT), popliteal artery blood flow, pressure-to-pain threshold (PPT), muscle hardness, heart rate variability, and perceived relaxation were measured before (Pre) and immediately after IPC treatment (Post-0) and 20 min after IPC treatment (Post-20), and the changes in all variables from Pre (Δ) were calculated. ΔWBLT performance, ΔPPT, and Δperceived relaxation in all IPC treatments were significantly higher than those in SHAM at Post-0 and Post-20 (p < 0.05). ΔPopliteal artery blood flow in BOOST80 and BOOST135 was significantly higher than that in SHAM and SQUEE80 at Post-0 (p < 0.05). ΔMuscle hardness and Δheart rate variability did not differ significantly between trials. In conclusion, IPC treatments, irrespective of applied pressure and mode of compression, increased ankle DF ROM. This resulted from decreased pain sensitivity (i.e., increased PPT). In addition, high inflation pressure and frequency did not provide additional benefits in increasing ankle DF ROM.

The potential therapeutic benefits of low frequency haemodynamic oscillations

Haemodynamic oscillations occurring at frequencies below the rate of respiration have been observed experimentally for more than a century. Much of the research regarding these oscillations, observed in arterial pressure and blood flow, has focused on mechanisms of generation and methods of quantification. However, examination of the physiological role of these oscillations has been limited. Multiple studies have demonstrated that oscillations in arterial pressure and blood flow are associated with the protection in tissue oxygenation or functional capillary density during conditions of reduced tissue perfusion. There is also evidence that oscillatory blood flow can improve clearance of interstitial fluid, with a growing number of studies demonstrating a role for oscillatory blood flow to aid in clearance of debris from the brain. The therapeutic potential of these haemodynamic oscillations is an important new area of research which may have beneficial impact in treating conditions such as stroke, cardiac arrest, blood loss injuries, sepsis, or even Alzheimer's disease and vascular dementia.

Effects of an external pneumatic compression device vs static compression garment on peripheral circulation and markers of sports performance and recovery

PURPOSE

To identify the effects of a single 30 min partial lower leg external pneumatic compression (EPC) treatment compared to a static compression (SC) garment or a no treatment control (CTL) on markers of recovery and performance following a muscle damaging protocol.

METHODS

Thirty healthy, active males (23 ± 3 years; 180.2 ± 9.0 cm; 81.6 ± 11.3 kg) performed 100 drop jumps from a 0.6 m box followed by a randomized, single 30 min treatment of either a partial lower leg EPC device worn below the knee and above the ankle (110 mmHg), SC garment (20-30 mmHg) covering the foot and calf just below the knee, or no treatment CTL, and then returned 24 and 48 h later. Participants were assessed for measures of muscle soreness, fatigue, hemodynamics, blood lactate, muscle thickness, circumferences, and performance assessments.

RESULTS

The drop jump protocol significantly increased muscle soreness (p < 0.001), fatigue (p < 0.001), blood flow (p < 0.001), hemoglobin (p < 0.001), and muscle oxygen saturation (SMO₂; p < 0.001). Countermovement jump and squat jump testing completed after treatment with either EPC, SC, or CTL revealed no differences for jump height between any condition. However, EPC treatment maintained consistent braking force and propulsive power measures across all timepoints for countermovement jump testing. EPC and SC treatment also led to better maintenance of squat jump performance for average relative propulsive force and power variables at 24 and 48 h compared to CTL.

CONCLUSIONS

A single 30 min partial leg EPC treatment may lead to more consistent jump performance following a damaging bout of exercise.

The Effect of Pressotherapy on Performance and Recovery in the Management of Delayed Onset Muscle Soreness: A Systematic Review and Meta-Analysis

Background: It has been demonstrated that pressotherapy used post-exercise (Po-E) can influence training performance, recovery, and physiological properties. This study examined the effectiveness of pressotherapy on the following parameters. Methods: The systematic review and meta-analysis were performed according to PRISMA guidelines. A literature search of MEDLINE, PubMed, EBSCO, Web of Science, SPORTDiscus, and ClinicalTrials has been completed up to March 2021. Inclusion criteria were: randomized control trials (RCTs) or cross-over studies, mean participant age between 18 and 65 years, ≥1 exercise mechanical pressotherapy intervention. The risk of bias was assessed by the Cochrane risk-of-bias tool for RCT (RoB 2.0). Results: 12 studies comprised of 322 participants were selected. The mean sample size was n = 25. Pressotherapy significantly reduced muscle soreness (Standard Mean Difference; SMD = −0.33; CI = −0.49, −0.18; p < 0.0001; I2 = 7%). Pressotherapy did not significantly affect jump height (SMD = −0.04; CI = −0.36, −0.29; p = 0.82). Pressotherapy did not significantly affect creatine kinase level 24−96 h after DOMS induction (SMD = 0.41; CI = −0.07, 0.89; p = 0.09; I2 = 63%). Conclusions: Only moderate benefits of using pressotherapy as a recovery intervention were observed (mostly for reduced muscle soreness), although, pressotherapy did not significantly influence exercise performance. Results differed between the type of exercise, study population, and applied treatment protocol. Pressotherapy should only be incorporated as an additional component of a more comprehensive recovery strategy. Study PROSPERO registration number—CRD42020189382.

Neither Peristaltic Pulse Dynamic Compressions nor Heat Therapy Accelerate Glycogen Resynthesis after Intermittent Running

PURPOSE

To investigate the effects of a single session of either peristaltic pulse dynamic leg compressions (PPDC) or local heat therapy (HT) after prolonged intermittent shuttle running on skeletal muscle glycogen content, muscle function, and the expression of factors involved in skeletal muscle remodeling.

METHODS

Twenty-six trained individuals were randomly allocated to either a PPDC (n = 13) or a HT (n = 13) group. After completing a 90-min session of intermittent shuttle running, participants consumed 0.3 g·kg-1 protein plus 1.0 g·kg-1 carbohydrate and received either PPDC or HT for 60 min in one randomly selected leg, while the opposite leg served as control. Muscle biopsies from both legs were obtained before and after exposure to the treatments. Muscle function and soreness were also evaluated before, immediately after, and 24 h after the exercise bout.

RESULTS

The changes in glycogen content were similar (P > 0.05) between the thigh exposed to PPDC and the control thigh ~90 min (Control: 14.9 ± 34.3 vs PPDC: 29.6 ± 34 mmol·kg-1 wet wt) and ~210 min (Control: 45.8 ± 40.7 vs PPDC: 52 ± 25.3 mmol·kg-1 wet wt) after the treatment. There were also no differences in the change in glycogen content between thighs ~90 min (Control: 35.9 ± 26.1 vs HT: 38.7 ± 21.3 mmol·kg-1 wet wt) and ~210 min (Control: 61.4 ± 50.6 vs HT: 63.4 ± 17.5 mmol·kg-1 wet wt) after local HT. The changes in peak torque and fatigue resistance of the knee extensors, muscle soreness, and the mRNA expression and protein abundance of select factors were also similar (P > 0.05) in both thighs, irrespective of the treatment.

CONCLUSIONS

A single 1-h session of either PPDC or local HT does not accelerate glycogen resynthesis and the recovery of muscle function after prolonged intermittent shuttle running.

Accelerating Recovery from Exercise-Induced Muscle Injuries in Triathletes: Considerations for Olympic Distance Races

The triathlon is one of the fastest developing sports in the world due to expanding participation and media attention. The fundamental change in Olympic triathlon races from a single to a multistart event is highly demanding in terms of recovery from and prevention of exercise-induced muscle injures. In elite and competitive sports, ultrastructural muscle injuries, including delayed onset muscle soreness (DOMS), are responsible for impaired muscle performance capacities. Prevention and treatment of these conditions have become key in regaining muscular performance levels and to guarantee performance and economy of motion in swimming, cycling and running. The aim of this review is to provide an overview of the current findings on the pathophysiology, as well as treatment and prevention of, these conditions in compliance with clinical implications for elite triathletes. In the context of DOMS, the majority of recovery interventions have focused on different protocols of compression, cold or heat therapy, active regeneration, nutritional interventions, or sleep. The authors agree that there is a compelling need for further studies, including high-quality randomized trials, to completely evaluate the effectiveness of existing therapeutic approaches, particularly in triathletes. The given recommendations must be updated and adjusted, as further evidence emerges.

Low-Load Resistance Training With Blood Flow Restriction Improves Clinical Outcomes in Musculoskeletal Rehabilitation: A Single-Blind Randomized Controlled Trial

Background: There is growing evidence to support the use of low-load blood flow restriction (LL-BFR) exercise in musculoskeletal rehabilitation.

Purpose: The purpose of this study was to evaluate the efficacy and feasibility of low-load blood flow restricted (LL-BFR) training versus conventional high mechanical load resistance training (RT) on the clinical outcomes of patient’s undergoing inpatient multidisciplinary team (MDT) rehabilitation.

Study design: A single-blind randomized controlled study.

Methods: Twenty-eight lower-limb injured adults completed a 3-week intensive MDT rehabilitation program. Participants were randomly allocated into a conventional RT (3-days/week) or twice-daily LL-BFR training group. Outcome measurements were taken at baseline and 3-weeks and included quadriceps and total thigh muscle cross-sectional area (CSA) and volume, muscle strength [five repetition maximum (RM) leg press and knee extension test, isometric hip extension], pain and physical function measures (Y-balance test, multistage locomotion test—MSLT).

Results: A two-way repeated measures analysis of variance revealed no significant differences between groups for any outcome measure post-intervention (p > 0.05). Both groups showed significant improvements in mean scores for muscle CSA/volume, 5-RM leg press, and 5-RM knee extension (p < 0.01) after treatment. LL-BFR group participants also demonstrated significant improvements in MSLT and Y-balance scores (p < 0.01). The Pain scores during training reduced significantly over time in the LL-BFR group (p = 0.024), with no adverse events reported during the study.

Conclusion: Comparable improvements in muscle strength and hypertrophy were shown in LL-BFR and conventional training groups following in-patient rehabilitation. The LL-BFR group also achieved significant improvements in functional capacity. LL-BFR training is a rehabilitation tool that has the potential to induce positive adaptations in the absence of high mechanical loads and therefore could be considered a treatment option for patients suffering significant functional deficits for whom conventional loaded RT is contraindicated.

Trial Registration: ISRCTN Reference: ISRCTN63585315, dated 25 April 2017.

Skeletal muscle amino acid transporter and BCAT2 expression prior to and following interval running or resistance exercise in mode-specific trained males

Endurance (END)- and resistance (RES)-trained males performed interval running or resistance exercise during three consecutive days (bouts 1-3). Muscle biopsies were obtained at baseline, 2 h post-bout 1, and 72 h post-bout 3. Amino acid transporter SNAT2 mRNA was 75% greater in END (group p = 0.008), and increased ~ 70% 2 h post in both groups (time p = 0.023). Amino acid transporter PAT1 mRNA was 2.7-fold greater in RES (group p = 0.002). Baseline protein levels of the mitochondrial aminotransferase BCAT2 were 79% greater in END (p = 0.015).

Acute and chronic resistance training downregulates select LINE-1 retrotransposon activity markers in human skeletal muscle

Herein, we examined if acute or chronic resistance exercise affected markers of skeletal muscle long interspersed nuclear element-1 (LINE-1) retrotransposon activity. In study 1, 10 resistance-trained college-aged men performed three consecutive daily back squat sessions, and vastus lateralis biopsies were taken before (Pre), 2 h following session 1 (Post1), and 3 days following session 3 (Post2). In study 2, 13 untrained college-aged men performed a full-body resistance training program (3 days/wk), and vastus lateralis biopsies were taken before ( week 0) and ~72 h following training cessation ( week 12). In study 1, LINE-1 mRNA decreased 42-48% at Post1 and 2 ( P < 0.05), and reverse transcriptase (RT) activity trended downward at Post2 (-37%, P = 0.067). In study 2, LINE-1 mRNA trended downward at week 12 (-17%, P = 0.056) while LINE-1 promoter methylation increased (+142%, P = 0.041). Open reading frame (ORF)2p protein expression (-24%, P = 0.059) and RT activity (-26%, P = 0.063) also trended downward by week 12. Additionally, changes in RT activity versus satellite cell number were inversely associated ( r = -0.725, P = 0.008). Follow-up in vitro experiments demonstrated that 48-h treatments with lower doses (1 μM and 10 μM) of efavirenz and nevirapine (non-nucleoside RT inhibitors) increased myoblast proliferation ( P < 0.05). However, we observed a paradoxical decrease in myoblast proliferation with higher doses (50 μM) of efavirenz and delavirdine. This is the first report suggesting that resistance exercise downregulates markers of skeletal muscle LINE-1 activity. Given our discordant in vitro findings, future research is needed to thoroughly assess whether LINE-1-mediated RT activity enhances or blunts myoblast, or primary satellite cell, proliferative capacity.

Concomitant external pneumatic compression treatment with consecutive days of high intensity interval training reduces markers of proteolysis

PURPOSE

To compare the effects of external pneumatic compression (EPC) and sham when used concurrently with high intensity interval training (HIIT) on performance-related outcomes and recovery-related molecular measures.

METHODS

Eighteen recreationally endurance-trained male participants (age: 21.6 ± 2.4 years, BMI: 25.7 ± 0.5 kg/m², VO_2peak: 51.3 ± 0.9 mL/kg/min) were randomized to balanced sham and EPC treatment groups. Three consecutive days of HIIT followed by EPC/sham treatment (Days 2-4) and 3 consecutive days of recovery (Days 5-7) with EPC/sham only on Days 5-6 were employed. Venipuncture, flexibility and pressure-to-pain threshold (PPT) measurements were made throughout. Vastus lateralis muscle was biopsied at PRE (i.e., Day 1), 1-h post-EPC/sham treatment on Day 2 (POST1), and 24-h post-EPC/sham treatment on Day 7 (POST2). 6-km run time trial performance was tested at PRE and POST2.

RESULTS

No group × time interaction was observed for flexibility, PPT, or serum measures of creatine kinase (CK), hsCRP, and 8-isoprostane. However, there was a main effect of time for serum CK (p = 0.005). Change from PRE in 6-km run times at POST2 were not significantly different between groups. Significant between-groups differences existed for change from PRE in atrogin-1 mRNA (p = 0.018) at the POST1 time point (EPC: - 19.7 ± 8.1%, sham: + 7.7 ± 5.9%) and atrogin-1 protein concentration (p = 0.013) at the POST2 time point (EPC: - 31.8 ± 7.5%, sham: + 96.0 ± 34.7%). In addition, change from PRE in poly-Ub proteins was significantly different between groups at both the POST1 (EPC: - 26.0 ± 10.3%, sham: + 34.8 ± 28.5%; p = 0.046) and POST2 (EPC: - 33.7 ± 17.2%, sham: + 21.4 ± 14.9%; p = 0.037) time points.

CONCLUSIONS

EPC when used concurrently with HIIT and in subsequent recovery days reduces skeletal muscle markers of proteolysis.

Effects of Whey, Soy or Leucine Supplementation with 12 Weeks of Resistance Training on Strength, Body Composition, and Skeletal Muscle and Adipose Tissue Histological Attributes in College-Aged Males

We sought to determine the effects of L-leucine (LEU) or different protein supplements standardized to LEU (~3.0 g/serving) on changes in body composition, strength, and histological attributes in skeletal muscle and adipose tissue. Seventy-five untrained, college-aged males (mean ± standard error of the mean (SE); age = 21 ± 1 years, body mass = 79.2 ± 0.3 kg) were randomly assigned to an isocaloric, lipid-, and organoleptically-matched maltodextrin placebo (PLA, n = 15), LEU (n = 14), whey protein concentrate (WPC, n = 17), whey protein hydrolysate (WPH, n = 14), or soy protein concentrate (SPC, n = 15) group. Participants performed whole-body resistance training three days per week for 12 weeks while consuming supplements twice daily. Skeletal muscle and subcutaneous (SQ) fat biopsies were obtained at baseline (T1) and ~72 h following the last day of training (T39). Tissue samples were analyzed for changes in type I and II fiber cross sectional area (CSA), non-fiber specific satellite cell count, and SQ adipocyte CSA. On average, all supplement groups including PLA exhibited similar training volumes and experienced statistically similar increases in total body skeletal muscle mass determined by dual X-ray absorptiometry (+2.2 kg; time p = 0.024) and type I and II fiber CSA increases (+394 μm² and +927 μm²; time p < 0.001 and 0.024, respectively). Notably, all groups reported increasing Calorie intakes ~600–800 kcal/day from T1 to T39 (time p < 0.001), and all groups consumed at least 1.1 g/kg/day of protein at T1 and 1.3 g/kg/day at T39. There was a training, but no supplementation, effect regarding the reduction in SQ adipocyte CSA (−210 μm²; time p = 0.001). Interestingly, satellite cell counts within the WPC (p < 0.05) and WPH (p < 0.05) groups were greater at T39 relative to T1. In summary, LEU or protein supplementation (standardized to LEU content) does not provide added benefit in increasing whole-body skeletal muscle mass or strength above PLA following 3 months of training in previously untrained college-aged males that increase Calorie intakes with resistance training and consume above the recommended daily intake of protein throughout training. However, whey protein supplementation increases skeletal muscle satellite cell number in this population, and this phenomena may promote more favorable training adaptations over more prolonged periods.