Low intensity resistance exercise training with blood flow restriction: insight into cardiovascular function, and skeletal muscle hypertrophy in humans

The level of actual functional fitness of men from different living environments in Poland and associations with health - a cross-sectional study

BACKGROUND

The study aimed to assess the differences in functional fitness between older men living in social welfare homes (SWH) and men living in society.

METHODS

The study involved 474 men aged 60-84, including 134 men living in social welfare homes and 340 men living in community. The Senior Fitness Test was used to assess functional fitness. Body weight and height were measured. Moreover, data on age, education, taking up physical activity and place of residence were collected.

RESULTS

A significantly lower level of functional fitness of SWH residents was demonstrated compared to men living in the society (p < 0.001). A significant percentage of seniors living in SWH did not reach the normal range for the Polish population. Also, the level of education, physical activity and health self-assessment differentiated the institutionalized men from those living in the community.

CONCLUSIONS

The place of residence is a factor that differentiates seniors' functional fitness levels. The reduced fitness of social welfare home residents may also result from the low level of their daily physical activity, education and health. Introducing physical activity programs for elderly residents in social welfare homes seems reasonable.

TRIAL REGISTRATION

ISRCTN platform as 18,225,729; December 2020.

A bibliometric analysis study of blood flow restriction using CiteSpace

[Purpose] To assess the current state-of-the-art and the prevailing trends regarding the global use of blood flow restriction (BFR) in the past 20 years. [Participants and Methods] We retrieved literature relating to BFR from 1999 to 2020 using Web of Science. We conducted a bibliometric analysis of countries/institutions, cited journals, authors/cited authors, cited references, and keywords using CiteSpace. An analysis of counts and centrality was used to examine publication output, countries/institutions, core journals, active authors, foundation references, hot topics, and frontiers. [Results] Seven hundred seventy five references were included and the total number of publications has been continually increasing over the investigated period. Representatives of important academic groups are the Japanese scholars from the University of Tokyo as represented by Takashi Abe. Jeremy Paul Loenneke’s article (centrality: 0.15) was the most representative and symbolic reference with the highest centrality. The three topics identified were intervention (intensity resistance exercise, IRE), physiology (ischemia and muscular function) and behavior (adaptation and increase). The four frontier topics were phosphorylation, reduction, low intensity and arterial occlusion. [Conclusion] This study provides an insight into BFR and offers valuable information for BFR researchers to identify new perspectives for potential cooperation with collaborators and their related cooperative institutions.

Heart rate and cardiac autonomic responses to concomitant deep breathing, hand grip exercise, and circulatory occlusion in healthy young adult men and women

BACKGROUND

Deep breathing (DB) and handgrip (HG) exercise -with and without circulatory occlusion (OC) in muscle-, have been shown to have beneficial effects on cardiovascular function; however, the combination of these maneuvers on heart rate (HR) and cardiac sympathovagal balance have not been previously investigated. Therefore, the aim of the present study was to evaluate the effect of simultaneous DB, HG, and OC maneuvers on the sympathovagal balance in healthy women and men subjects.

METHODS AND RESULTS

Electrocardiogram and ventilation were measured in 20 healthy subjects (Women: n = 10; age = 27 ± 4 years; weight = 67.1 ± 8.4 kg; and height = 1.6 ± 0.1 m. Men: n = 10; age = 27 ± 3 years; weight = 77.5 ± 10.1 kg; and height = 1.7 ± 0.1 m) at baseline and during DB, DB + HG, or DB + HG + OC protocols. Heart rate (HR) and respiratory rate were continuously recorded, and spectral analysis of heart rate variability (HRV) were calculated to indirectly estimate cardiac autonomic function. Men and women showed similar HR responses to DB, DB + HG and DB + HG + OC. Men exhibited a significant HR decrease following DB + HG + OC protocol which was accompanied by an improvement in cardiac autonomic control evidenced by spectral changes in HRV towards parasympathetic predominance (HRV High frequency: 83.95 ± 1.45 vs. 81.87 ± 1.50 n.u., DB + HG + OC vs. baseline; p < 0.05). In women, there was a marked decrease in HR after completion of both DB + HG and DB + HG + OC tests which was accompanied by a significant increase in cardiac vagal tone (HRV High frequency: 85.29 ± 1.19 vs. 77.93 ± 0.92 n.u., DB + HG vs. baseline; p < 0.05). No adverse effects or discomfort were reported by men or women during experimental procedures. Independent of sex, combination of DB, HG, and OC was tolerable and resulted in decreases in resting HR and elevations in cardiac parasympathetic tone.

CONCLUSIONS

These data indicate that combined DB, HG and OC are effective in altering cardiac sympathovagal balance and reducing resting HR in healthy men and women.

Resistance Training with Blood Flow Restriction on Vascular Function: A Meta-analysis

In this meta-analysis, the aims were to examine the effects of resistance training with and without blood flow restriction on vascular function. Five databases were searched up to June 2020 for papers about resistance training with blood flow restriction influence on vascular function. The quality of each identified study was evaluated. Effect sizes were estimated in terms of the standardized mean difference. A subgroup analysis was conducted according to participants' age, training duration, and cuff pressure. The results of six studies on arterial compliance and five on vascular function were highly homogenous regarding responses to resistance training with or without blood flow restriction. Resistance training with blood flow restriction had a more positive effect for regulating arterial compliance than resistance training without blood flow restriction, but not for vascular function. Resistance training with blood flow restriction leads to a more positive effect on vascular function than resistance training when training for no longer than four weeks.

Effects of combined treatment with blood flow restriction and low-intensity electrical stimulation on diabetes mellitus-associated muscle atrophy in rats

BACKGROUND

Diabetes mellitus (DM) results in decreased muscle mass and harmful complications. Blood flow restriction (Bfr) and electrical stimulation (ES) increase muscle protein synthesis. We hypothesized that combined Bfr and low-intensity ES may be more effective in preventing diabetes-associated muscle atrophy by inhibiting the downregulation of protein synthesis-related pathways. In this study, the effects of combined Bfr and low-intensity ES on diabetes-associated muscle atrophy were investigated by evaluating advanced glycation end-products (AGEs) and receptor for AGEs (RAGE) in rats.

METHODS

Twenty-four Goto-Kakizaki (GK) rats were randomly divided into four treatment groups: sedentary DM, DM + Bfr (pressure cuffs placed around the thigh), DM + ES, and DM + Bfr + ES. Six Wistar rats were used as an age-matched control. Levels of AGEs and the expression of RAGE, extracellular signal-regulated kinase (ERK), and ribosomal protein S6 (rpS6) were determined in plantaris muscles.

RESULTS

Diabetes resulted in a loss of muscle mass and upregulation of AGEs and RAGE in the plantaris muscle compared with the control group. Treatment with Bfr and ES alone failed to attenuate diabetes-associated loss of muscle mass, and could not prevent the upregulation of AGEs. However, the combination of Bfr and ES prevented the diabetes-associated decrease in muscle mass and upregulation of AGEs. In addition, the combination treatment prevented diabetes-associated decreases in the expression of phosphorylated rpS6.

CONCLUSIONS

Combination treatment with Bfr and ES may prevent diabetes-associated muscle atrophy by upregulating inhibition of AGEs, which leads to the activation of protein synthesis.

Application of Blood Flow Restriction to Optimize Exercise Countermeasures for Human Space Flight

In recent years there has been a strong increase in publications on blood flow restriction (BFR) training. In particular, the fact that this type of training requires only low resistance to induce muscle strength and mass gains, makes BFR training interesting for athletes and scientists alike. For the same reason this type of training is particularly interesting for astronauts working out in space. Lower resistance during training would have the advantage of reducing the risk of strain-induced injuries. Furthermore, strength training with lower resistances would have implications for the equipment required for training under microgravity conditions, as significantly lower resistances have to be provided by the training machines. Even though we are only about to understand the effects of blood flow restriction on exercise types other than low-intensity strength training, the available data indicate that BFR of leg muscles is also able to improve the training effects of walking or running at slow speeds. The underlying mechanisms of BFR-induced functional and structural adaptations are still unclear. An essential aspect seems to be the premature fatigue of Type-I muscle fibers, which requires premature recruitment of Type-II muscle fibers to maintain a given force output. Other theories assume that cell swelling, anabolic hormones, myokines and reactive oxygen species are involved in the mediation of BFR training-related effects. This review article is intended to summarize the main advantages and disadvantages, but also the potential risks of such training for astronauts.

OXYGEN UPTAKE AND RESISTANCE EXERCISE METHODS: THE USE OF BLOOD FLOW RESTRICTION

ABSTRACT Introduction: The literature has shown that a gap is identified regarding the acute effects of blood flow restriction training on aerobic variables. Objective: to analyze oxygen consumption (VO2) during and after two resistance training sessions: traditional high intensity and low intensity with blood flow restriction. Methods: After one-repetition maximum tests, eight male participants (25.7±3 years) completed the two experimental protocols, separated by 72 hours, in a randomized order: a) high intensity training at 80% of 1RM (HIRE) and b) low intensity training at 20% of 1RM combined with blood flow restriction (LIRE + BFR). Three sets of four exercises (bench press, squat, barbell bent-over row and deadlift) were performed. Oxygen consumption and excess post-exercise oxygen consumption were measured. Results: the data showed statistically significant differences between the traditional high intensity training and low intensity training with blood flow restriction, with higher values for traditional training sessions, except for the last five minutes of the excess post-exercise oxygen consumption. Oxygen consumption measured during training was higher (p = 0.001) for the HIRE (20.32 ± 1.46 mL·kg-1·min-1) compared to the LIRE + BFR (15.65 ± 1.14 mL·kg-1·min-1). Conclusion: Oxygen uptakes rates during and after the exercise sessions were higher for the high intensity training methodology. However, when taking into account the volume of training provided by both methods, these differences were attenuated. Level of Evidence III - Non-consecutive studies, or studies without consistently applied reference stand.