Blood flow after contraction and cuff occlusion is reduced in subjects with muscle soreness after eccentric exercise

Blood Flow Restriction Is Not Useful as Soccer Competition Recovery in Youth Male National-Level Soccer Players: A Crossover Randomised Controlled Trial

In soccer, blood flow restriction (BFR) is used to optimise between-match recovery. However, the benefits are unclear. This study evaluated the effects of BFR as a recovery strategy after a competition on countermovement jump (CMJ) height, rating of perceived exertion (RPE) and the wellness of soccer players. Forty national-level soccer players were allocated into two conditions: BFR (an active recovery session wearing a BFR device, 24 h after a competition) or NoBFR (the same recovery without BFR). CMJ, RPE and wellness were evaluated the day (CMJ and RPE) or the morning (wellness) before the competition; just after the competition (CMJ and RPE); and 24, 48 (wellness) and 72 h later. After 4 weeks, the players changed conditions. All players showed impaired CMJ (p = 0.013), RPE (p < 0.001) and wellness (p < 0.001) after the match compared with the baseline. The CMJ returned to the baseline 24 h later and wellness returned 48 h later. Only in the BFR condition did the RPE remain impaired 24 h after the match, which was also the moment after finishing the BFR recovery session (p < 0.001). BFR during active recovery does not provide any additional benefits compared with traditional exercise modalities to recover CMJ, RPE and wellness in youth national-level soccer players. BFR could even induce an immediate higher RPE.

Detection of blood flow perfusion and post - occlusive reactive hyperemia in the skeletal muscle of rats

AIMS

Post-occlusive reactive hyperemia (PORH) remains poorly understood in the skeletal muscle system. This study was designed to validate an alternative strategy of PORH detection in rodents. Additionally, we explored the hypothesis that PORH is influenced by experimental models associated with impaired function of the skeletal muscle.

MATERIALS AND METHODS

Wistar rats were anesthetized, and blood flow was assessed by laser Doppler in the anterior tibialis muscle, before and immediately after 5 s, 30 s, 3 min, or 5 min of flow occlusion, obtained through a cuff inflated to 300 mmHg around the thigh of the animals.

KEY FINDINGS

In healthy animals, deflating the cuff resulted in a fast increment of local blood flow, characterizing the PORH after 5 s to 5 min of cuff occlusion and its dependence on flow occlusion duration. Importantly, we found different profiles of PORH in animals pretreated with reserpine (accelerated peak and reduced half recovery time), streptozotocin (increased peak), or subjected to muscle contraction in stretching (delayed peak), approaches used as experimental models to study fibromyalgia, type II diabetes mellitus, and soreness induced by unaccustomed eccentric exercise, respectively.

SIGNIFICANCE

We demonstrated that the profile of PORH in the anterior tibialis muscle of rats is sensitive to a variety of experimental models often associated with the skeletal muscle functionality, providing a useful strategy to explore how and whether changes in local regulation of blood flow can contribute to the development of skeletal muscle associated symptoms in clinically relevant conditions.

Effect of Kinesio taping on delayed-onset muscle soreness in elite athletes

BACKGROUND

This research analyzes the effect of Kinesio taping on delayed-onset muscle soreness in elite athletes because delayed-onset muscle soreness increases the risk of injury in sports.

METHODS

Elite female volleyball players (n=31) were randomly divided into experimental (n=16, with Kinesio taping of the knee) and control (n=15) groups. To elicit delayed-onset soreness in knee joint muscles, the protocol that we used consisting of downhill running, visual analog pain score assessment, and measurements of serum interleukin-6 and creatine kinase concentrations immediately and after 24 hours, 48 hours, and 72 hours.

RESULTS

Compared with the control group, the pain reported by the athletes with Kinesio taping decreased 24 hours and 48 hours (P<0.05) after running, but there was no significant difference 72 hours (P<0.05) after running. Interleukin-6 concentrations were lower in the athletes with Kinesio taping than those in the control group immediately and 24 hours (P<0.05) after running, but there was no significant difference 48 hours and 72 hours (P<0.05) after running. There were no significant differences (P>0.05) in creatine kinase concentrations.

CONCLUSIONS

The use of Kinesio taping in elite athletes is an effective protective strategy for alleviating pain symptoms caused by delayed-onset muscle soreness, but it is not effective to alleviate the skeletal muscle microinjury caused by delayed-onset muscle soreness.

Effects of Pre-exercise Acute Vibration Training on Symptoms of Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis

Tan, J, Shi, X, Witchalls, J, Waddington, G, Lun Fu, AC, Wu, S, Tirosh, O, Wu, X, and Han, J. Effects of pre-exercise acute vibration training on symptoms of exercise-induced muscle damage: a systematic review and meta-analysis. J Strength Cond Res XX(X): 000-000, 2020-Exercise-induced muscle damage (EIMD) normally occurs after unaccustomed high-intensity eccentric exercises. Symptoms of EIMD include delayed-onset muscle soreness (DOMS), tenderness, stiffness, swelling, reduced strength, and increased creatine kinase (CK) levels in the blood. Vibration training (VT) may be useful as a pre-exercise intervention in attenuating EIMD on the basis of tonic vibration reflex (TVR) through a more efficient distribution of contractile stress over muscle fibers. The objective of this meta-analysis is to examine the effects of acute VT on symptoms of EIMD when performed as the pre-exercise intervention. Randomized controlled trials (RCTs) published in the 8 databases of Cochrane Library, PubMed, Embase, Web of Science, EBSCO, China National Knowledge Infrastructure, Airiti Library and WanFang Data from 1966 (the earliest available time) to January 2019 were searched. A total of 2,324 records were identified and 448 articles were screened with the title and abstract. Two investigators identified eligible studies, extracted data, and assessed the risk of bias independently. Review Manager 5.3 designed by Cochrane was used for the current meta-analysis. Six RCTs involving 180 subjects were included in the analysis. A low-to-moderate methodological quality of the included studies was revealed using the physiotherapy evidence database scale. The results showed that acute VT was superior to the control group for the reduction of DOMS on pain visual analogue scale at 24, 48 hours and pressure pain threshold at 24 hours. In addition, superior effects of acute VT were also found on the indirect markers of muscle damage including CK at 24, 72 hours, and lactate dehydrogenase at 24 hours. The current meta-analysis has collated the evidence to demonstrate that receiving acute VT before unaccustomed high-intensity eccentric exercises may be effective in attenuating markers of muscle damage and the development of DOMS when compared with a control group. The possible mechanisms of this effect could be attributed to an improved synchronization of muscle fiber caused by TVR, which could result in even distribution of exterior loads and eventually attenuate disruptions of muscle fibers. In addition, increased blood flow may also be helpful to prevent accumulation of metabolic substances and attenuate subsequent symptoms of EIMD. Vibration training may be used as a pre-exercise intervention to alleviate symptoms of EIMD caused by unaccustomed high-intensity eccentric exercise. Because of the limited quantity and quality of included studies, more high-quality studies are required to ascertain the effect of VT on symptoms of EIMD.

Relationships between resting blood flow and the indices of muscle damage after eccentric contractions

PURPOSE

The aim of the study is to examine the relationships between increments in resting blood flow and isometric maximal voluntary contraction (MVC) force reduction, muscle soreness, and swelling after eccentric contractions (ECs).

METHODS

Twenty-one young healthy men (age 20.8 ± 1.6 years; height 172.0 ± 5.3 cm; weight 64.9 ± 7.7 kg) were recruited for this study. All participants performed right arm ECs in five sets of 20 repetitions with 3 min of rest between the sets. The dumbbell weight corresponded to 60% MVC force of isometric contraction of elbow flexors with 90° elbow joint angle. Resting forearm blood flow (FBF), the MVC force, the muscle thickness (MT), and muscle soreness of elbow flexors, heart rate (HR), and blood pressure (BP) of brachial artery were measured before, 24 and 48 h after ECs.

RESULTS

Average and peak resting FBF after ECs significantly changed from the average values before ECs (21% and 39% increase, respectively, P < 0.01). However, resting HR and BP were not significantly different after ECs. Average increase in resting FBF showed a significant relationship with average isometric MVC force reduction (r =  - 0.45, P < 0.05), peak isometric MVC force reduction (r =  - 0.48, P < 0.05), average muscle soreness (r = 0.49, P < 0.05), and peak muscle soreness (r = 0.49, P < 0.05). Moreover, stepwise multiple regression analysis revealed that average increased resting FBF was explained by isometric MVC force reduction and muscle soreness (adjusted R² = 0.33).

CONCLUSIONS

These results suggested that increments in resting blood flow reflect muscle damage, and increased resting blood flow may be a result of acute inflammatory response induced by muscle damage.

Impaired microvascular reactivity after eccentric muscle contractions is not restored by acute ingestion of antioxidants or dietary nitrate

Unaccustomed eccentric exercise leads to impaired microvascular function but the underlying mechanism is unknown. In this study, we evaluated the role of oxidative stress and of nitric oxide (NO) bioavailability. Thirty young men and women performed eccentric contractions of the tibialis anterior (TA) muscle (ECC), with the contralateral leg serving as nonexercising control (CON). Participants were randomized into three groups ingesting an antioxidant cocktail (AO), beetroot juice (BR) or placebo 46 h postexercise. At baseline and 48 h postexercise, hyperemic responses to brief muscle contractions and 5 min of cuff occlusion were assessed bilaterally in the TA muscles using blood oxygen level dependent (BOLD) magnetic resonance imaging. Eccentric contractions resulted in delayed time-to-peak (~22%; P < 0.001), blunted peak (~21%; P < 0.001) and prolonged time-to-half relaxation (~12%, P < 0.001) in the BOLD response to brief contractions, with no effects of AO or BR, and no changes in CON. Postocclusive time-to-peak was also delayed (~54%; P < 0.001) in ECC, with no effects of AO or BR, and no changes in CON. Impaired microvascular reactivity after eccentric contractions is confined to the exercised tissue, and is not restored with acute ingestion of AO or BR. Impairments in microvascular reactivity after unaccustomed eccentric contractions may result from structural changes within the microvasculature that can diminish muscle blood flow regulation during intermittent activities requiring prompt adjustments in oxygen delivery.

Distinct effects of thermal treatments after lengthening contraction on mechanical hyperalgesia and exercise-induced physiological changes in rat muscle

Delayed-onset muscle soreness (DOMS) is a common but displeasing event induced by excessive muscle use or unaccustomed exercise and characterized by tenderness and movement-related pain in the exercised muscle. Thermal therapies, either icing or heating applied to muscles immediately after exercise, have been used as therapeutic interventions for DOMS. However, the mechanisms of their analgesic effects, and physiological and metabolic changes in the muscle during thermal therapy, remain unclear. In the present study, we investigated the effects of both thermal treatments on mechanical hyperalgesia of DOMS and physiological and muscle metabolite changes using the rat DOMS model induced by lengthening contraction (LC) to the gastrocnemius muscle. Heating treatment just after LC induced analgesic effects, while rats with icing treatment showed mechanical hyperalgesia similar to that of the LC group. Furthermore, increased physiological responses (e.g., muscle temperature and blood flow) following the LC were significantly kept high only in the rats with heating treatment. In addition, heating treatment increased metabolites involved in the improvement of blood flow and oxidative metabolisms in the exercised muscle. The results indicated that heating treatment just after LC has analgesic effects on DOMS, which might be mediated partly through the improvement of muscle oxidative metabolisms by changes in metabolites and elevated physiological responses.NEW & NOTEWORTHY Physiological effects of thermal therapy in the muscle and its mechanisms of analgesic effects remain unclear. The results indicated that heating, but not icing, treatment just after lengthening contractions induced analgesic effects in the rat muscle. Increases in hemodynamics, muscle temperature, and metabolites such as nicotinamide were more prominent in heating treatment, consistent with improvement of muscle oxidative metabolisms, which might reduce chemical factors to induce mechanical hyperalgesia.

Hemorheological alterations following an acute bout of nordic hamstring exercise in active male participants1

BACKGROUND

The Nordic hamstring exercise (NHE) has been proven to be an effective preventive technique for hamstring injuries. Hemorheological parameters (erythrocyte deformability and aggregation) play a critical role in exercise influencing oxygenation. Although previous studies presented hemorheological alterations induced by different types of exercise, changes in red blood cell (RBC) deformability and aggregation following NHE remain unknown. Present study was designed to explore possible alterations in hemorheological and oxidative parameters after an acute bout of NHE.

METHODS

10 healthy, male, active students (mean age 19.9±0.23, BMI: 21.56±0.54) participated to the study. They performed a single session of seven-repetitions of NHE followed by a familiarisation period. Blood samples were obtained before and immediately after the exercise from the antecubital vein. Hemorheological parameters were measured by an ektacytometer.

RESULTS

NHE did not change deformability, hematocrit and oxidative stress but, increased RBC aggregation index (AI, p = 0.011) and decreased RBC aggregation half time (t½, p = 0.009).

CONCLUSIONS

Our results suggest that, increased RBC aggregation following an acute bout of NHE may result in increased plasma skimming and thus ease the flow of blood.