Untrained Women Research Articles

Dose-response effects of 8-week resistance training on body composition and muscular performance in untrained young women: A quasi-experimental design.

The purpose of this study was to investigate the effects of 8-week resistance training with different training volumes on body composition, maximum strength, peak power, and muscle thickness in non-training women. This was a 3-arm, prospectively designed, randomized controlled trial. A total of 45 adult women aged 20.7 ± 1 years, the mean heights of the participants were 166 ± 0.07 cm, body weight was measured as 54.5 ± 8.8 kg, and body mass index was 19.9 ± 2.1 kg/m2. They were randomized to low-volume training resistance training (LVT; n = 15, 3 sessions of 12 exercises per week), moderate-volume training resistance training (MVT; n = 15; 4 sessions of 12 exercises per week), and high-volume resistance training (HVT; n = 15; 5 sessions of 12 exercises per week) for 8 weeks. The muscle thickness (MT) of the vastus lateralis was assessed at baseline and 8 weeks later using a portable ultrasound device. A total of 39 adult women completed the study, with 2 participants from each group lost to follow-up. All experimental groups 1RM increased (P = .001, effect size (ES) = 0.463) All groups showed improved muscle thickness (MT) (P = .001) and CMJ (P = .004). The group × time interaction is statistically significant (P = .001) suggests that the changes in muscle thickness over time differ significantly between the different training volume groups (ηp²) is 0.368. In untrained young women, resistance training improved muscle hypertrophy, maximal strength, power, and body composition in untrained young women. However, 4 sessions MVT per week were superior to LVT and HVT sessions, suggesting a nonlinear dose-response relationship favoring moderate volume over low or high volumes, at least in previously untrained young women. ClinicalTrials.gov (NCT06449300).

Assessment of the functional capabilities of the heart and the severity of the stress response in women 30-49 years old who are starting to engage in fitness

In this article, based on the results of scientific publications, the current state of the fitness industry development in Kazakhstan in terms of the volume of fitness services and the number of people involved is studied. The results of our own research are presented using modern technologies: in particular, using the method of cardioscanning of cardiovascular system indicators, assessing the fitness level and cardiostress index, as well as based on bioimpedance analysis, the body mass index of untrained women (30-49 years old) of the Royal Club Bukhar Zhyrau fitness club in Almaty in a state of relative rest was determined. The bicycle ergometry method was used to assess the response of hemodynamic indicators of the surveyed contingent to standard physical activity of subthreshold intensity. The obtained data were processed using the methods of mathematical statistics and correlation analysis, analyzed, summarized and formulated in the research results.

Potential Effects of Lifelong Team Handball and Football Training and Nutritional Habits on Bone Health and Body Composition in Elderly Women.

The aim of this study was to evaluate the effects of lifelong team handball/football training on regional bone health and body composition in elderly women. Seventeen elderly women team handball/football players (65.9 ± 5.7 years) and twenty-one untrained age-matched women (controls) (67.7 ± 5.1 years) participated. Whole-body and regional dual-energy X-ray absorptiometry scans of arms, legs, and lower spine (L1-L4) were performed. We observed 8% and 9% higher bone mineral density (BMD) and bone mineral content (BMC), respectively, at the whole-body level and in the legs and 11.5% higher BMC in the legs in team handball/football players compared to untrained age-matched controls (p < 0.05). Higher total and leg lean body mass (p < 0.05), along with lower total body fat percentage (p < 0.05) and higher T- and Z-scores, markers of fragility risk fracture (0.294 ± 1.461 vs. -0.538 ± 1.031; 1.447 ± 1.278 vs. 0.724 ± 0.823, respectively), were also found in team handball/football players compared to controls (p < 0.05). No significant differences in nutritional habits were observed between groups. Our study suggest that the beneficial effects of lifetime handball/football practice on bone preservation in elderly women occur independently from nutritional intake, which emphasize the potential role of team sports in osteoporosis prevention. Future studies should focus on the cofounding factors and causative mechanisms mediated by team sport practice in osteoporosis prevention.

Muscle memory in humans: evidence for myonuclear permanence and long-term transcriptional regulation after strength training.

The objective of this work was to investigate myonuclear permanence and transcriptional regulation as mechanisms for cellular muscle memory after strength training in humans. Twelve untrained men and women performed 10weeks of unilateral elbow-flexor strength training followed by 16weeks of de-training. Thereafter, 10weeks' re-training was conducted with both arms: the previously trained arm and the contralateral untrained control arm. Muscle biopsies were taken from the trained arm before and after both training periods and from the control arm before and after re-training. Muscle biopsies were analysed for fibre cross-sectional area (fCSA), myonuclei and global transcriptomics (RNA sequencing). During the first training period, myonuclei increased in type 1 (13 ± 17%) and type 2 (33 ± 23%) fibres together with a 30 ± 43% non-significant increase in mixed fibre fCSA (P=0.069). Following de-training, fCSA decreased in both fibre types, whereas myonuclei were maintained, resulting in 33% higher myonuclear number in previously trained vs. control muscle in type 2 fibres. Furthermore, in the previously trained muscle, three differentially expressed genes (DEGs; EGR1, MYL5 and COL1A1) were observed. Following re-training, the previously trained muscle showed larger type 2 fCSA compared to the control (P=0.035). However, delta change in type 2 fCSA was not different between muscles. Gene expression was more dramatically changed in the control arm (1338 DEGs) than in the previously trained arm (822 DEGs). The sustained higher number of myonuclei in the previously trained muscle confirms myonuclear accretion and permanence in humans. Nevertheless, because of the unclear effect on the subsequent hypertrophy with re-training, the physiological benefit remains to be determined. KEY POINTS: Muscle memory is a cellular mechanism that describes the capacity of skeletal muscle fibres to respond differently to training stimuli if the stimuli have been previously encountered. This study overcomes past methodological limitations related to the choice of muscles and analytical procedures. We show that myonuclear number is increased after strength training and maintained during de-training. Increased myonuclear number and differentially expressed genes related to muscle performance and development in the previously trained muscle did not translate into a clearly superior responses during re-training. Because of the unclear effect on the subsequent hypertrophy and muscle strength gain with re-training, the physiological benefit remains to be determined.

A SCIENTIFIC STUDY ON HEART RATE AND MUSCULAR ENDURANCE OF AEROBIC, ANAEROBIC AND COMBINED AEROBIC AND ANAEROBIC ACTIVITIES AMONG ELITE WOMEN

A planned, systematic and chronic training regimen will always leads to significant adaptations on physical and cardiac functions. The heart is an involuntary organ which directly get impact by any systematic training protocol as compared to any other organ of the body, based on this the investigator is throwing a light on how a long distance running training, middle distance running and weight lifting training protocol leads to a significant impact on heart rate at rest and muscular endurance. To fulfill the objectives of the study the investigator has chosen (N=45) elite women volunteered athletes of each (N=15) of long distance running, middle distance running and weight lifting, between 18 to 22 years. All the volunteered elite athletes are trained by their coaches for about 7 to 9 years. The selected criterian parameters are Heart Rate at rest (HR) and Muscular endurance, and they were measure by M- Mode Doppler Echocardiography with the support of qualified cardiologist and bent knee sit-ups (1 min) respectively. The level of significance is set at 0.01 level of assurance. The investigator has concluded that a regular and systematic long distance running, middle distance running and weight lifting training have significantly brought desired changes in heart rate at rest and muscular endurance as compared the normal, healthy, and untrained women reference values. Further, the investigation come to an that the long distance running has significantly lowered heart rate at rest, and significantly enhanced muscular endurance as compared to the middle distance running and weight lifting groups. In ordered to find out the significant difference the analysis of variance (ANOVA) was employed. When the ‘F’ ratio is significant, the Scheffe’s post-hock test was used to find the paired mean significant difference, if any, among the groups of chosen parameters. KEYWORDS: long distance running, middle distance running, weight lifting, heart rate at rest, muscular endurance

Bigger Calves from Doing Higher Resistance Training Volume?

We compared the effects of different weekly calf training sets on muscle size changes. Sixty-one untrained young women performed a calf training program for 6 weeks, 3 d·wk-1, with differences in resistance training volume. The participants were randomly assigned to one of the three groups: 6-SET, 9-SET, and 12-SET weekly calf training sets. The calf raise exercise was performed in sets of 15-20 repetitions maximum. The muscle thickness measurements of medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SOL) were taken via B-mode ultrasound. We used the sum of the three-muscle thickness as a proxy for the triceps surae (TSSUM). The 12-SET group elicited greater increases than the 6-SET in LG (6-SET=+ 8.1% vs. 12-SET=+ 14.3%; P=0.017), SOL (6-SET=+ 6.7% vs. 12-SET=+ 12.7%; P=0.024), and TSSUM (6-SET=+ 6.9% vs. 12-SET=+ 12.0%; P=0.005), but there was no significant difference in MG changes (6-SET=+ 6.6% vs. 12-SET=+ 9.9%; P=0.067). There were no significant differences when comparing 9-SET vs. 6-SET and 12-SET (P≥0.099). Although all groups experienced calf muscle hypertrophy, our results suggest that the higher dose range may optimize triceps surae muscle size gains.

Response Time of Elite Female Wrestlers

Abstract Introduction. Response time is a crucial factor influencing performance effectiveness in wrestling. A short time of response enables athletes to engage in more effective technical and tactical actions. Despite numerous scientific studies on psychomotor abilities in combat sports, there is a lack of scientific reports on women’s wrestling, especially at the highest level of performance. The aim of this study was to determine the response time of female wrestlers with different levels of sports advancement and weight classes. Material and Methods. Female wrestlers aged 19.08 ± 0.86 years with a training experience of 7.03 ± 1.33 years participated in the study, along with women not involved in sports training, aged 19.23 ± 0.70 years. Due to body weight, athletes were divided into two groups: lightweight and heavyweight, and based on sports achievements into medalists and non-medalist participants in the Polish Championships. Response time (including reaction time and movement time) was assessed. Results. The research results revealed differences in response time between wrestlers and untrained women. Wrestlers exhibited shorter response times in both reaction time and movement time. No significant differences in response time were noted between wrestlers based on weight class and sports result. Conclusions. Specialized wrestling training improves the response time of women, both in sensory and motor aspects. Body weight and sports results do not differentiate athletes based on response time. Further research should focus on determining different types of response time, including choice reaction, and their changes under the influence of training and competitive loads in wrestlers with varying levels of sports expertise. Additionally, effective training methods for improving reaction time should be explored.

Intermittent Hypoxic Training Increases and Prolongs Exercise Benefits in Adult Untrained Women.

Alba Camacho-Cardenosa, Marta Camacho-Cardenosa, Johannes Burtscher, Pedro R. Olivares, Guillermo Olcina, and Javier Brazo-Sayavera. Intermittent hypoxic training increases and prolongs exercise benefits in adult untrained women. High Alt Med Biol. 00:00-00, 2024. Background: Exercising in hypoxia may confer multiple health benefits, but the evidence for specific benefits is scarce. Methods: We investigated effects of intermittent hypoxic training (IHT) on the quality of life and functional fitness of healthy adult women, in a double-blind, randomized, placebo-controlled study. Subjects performed 36 sessions of IHT (experimental group, n = 41; fraction of inspired oxygen [FIO2]: 0.17) or the same training in normoxia (control group, n = 41; FIO2: 0.21). Health-related quality of life, fitness tests, and hemoglobin levels were assessed before (T1), directly after (T2), and 4 weeks after (T3) cessation. Results: At T2, upper body strength (+14.96%), lower body strength (+26.20%), and agility (-4.94%) increased significantly in the experimental group compared to baseline but not in controls.The experimental group improved lower body strength more (by 9.85%) than controls at T2 and performed significantly better in walking (by 2.92%) and upper body strength testing (by 16.03%), and agility (by 4.54%) at T3. Perceived general health and vitality was significantly greater in the experimental group at T2 and T3 compared with T1. None of these improvements were observed in the control group. Conclusions: IHT is a promising strategy to induce long-lasting fitness benefits in healthy adult women.

Investigation on Transient Receptor Potential Vanilloid 1 (TRPv1) Activation in Skeletal Muscle: Pilot Studies

Transient Receptor Potential Vanilloid 1 (TRPv1) is a Ca2+ ion channel predominately studied in neuronal cells and has been found to have sex-differential expression in mouse arterial smooth muscle. More recently, TRPv1 expression has also been observed in skeletal muscle. Among other stimuli, osmotic stress has shown to activate TRPv1 in different tissues (e.g., retinal ganglion and supraoptic nuclear cells). However, the effect of hyperglycemia- and dehydration-induced osmotic stress and the sex-differential expression on TRPv1 in skeletal muscle is not known. PURPOSES: To examine the effect of sex ( Pilot 1), hyperglycemia ( Pilot 2), and dehydration ( Pilot 3) on TRPv1 in skeletal muscle. HYPOTHESES: We hypothesized that TRPv1 would be different between sexes ( Pilot 1), would be higher in hyperglycemic rats compared to healthy controls ( Pilot 2), and would be greater in dehydrated than hydrated state in men ( Pilot 3). METHODS: To accomplish these purposes, we analyzed a subset of samples from three previously completed projects. Pilot 1: Vastus lateralis (VL) muscles were collected from untrained men ( n=3) and women ( n=3) at baseline. Pilot 2: Rats fed a high fat diet and injected with streptozotocin (35 mg/kg) (HFD; n=3; non-fasting blood glucose (NFBG) ≥300mg/dL) were compared to rats fed a normal diet (CON; n=3; NFBG &lt;300mg/dL). Soleus (Sol) muscle was collected after 7 weeks of feeding. Pilot 3: Lastly, VL muscles were collected from trained men (n=5) either dehydrated (DEHY; 296 ± 6 plasma mmol/kg) or hydrated (EUHY; 283 ± 5 plasma mmol/kg) for 24 hours. Rat Sol and human VL samples were analyzed for TRPv1 and p-TRPv1ser502 protein content. TRPv1 activation was calculated as p-TRPv1ser502/ TRPv1/ total protein. Student’s T-tests and effect sizes (ES; small [≤0.49], medium [0.5-0.79], or large [≥0.8] effect) were used to detect differences. Results: Pilot 1: A significant ( p&lt;0.05) difference was observed for TRPv1 with greater expression in men than women (43%, p=0.03, d=2.757). A medium ES was observed for TRPv1 activation (31%, p=0.42, d=0.728) being greater in men compared to women. Pilot 2: No significant difference was observed for TRPv1 and TRPv1 activation between CON and HFD rats. A medium ES was observed for TRPv1 expression (-9%, p=0.31, d=0.441) being lower in HFD compared to CON. A large effect size was observed for TRPv1 activation (30%, p=0.18, d=1.689) being greater in HFD compared to CON. Pilot 3: No significant difference was observed for TRPv1 and TRPv1 activation between EUHY and DEHY. A large ES was observed for TRPv1 (34%, p=0.15, d=0.995) and small ES was observed for TRPv1 activation (2%, p=0.80, d=0.164) being greater in DEHY compared to EUHY. CONCLUSION: These data are the first to illustrate the potential difference in TRPv1 in skeletal muscle. Future research is needed to explore the impact of differential TPRv1 activation on downstream Ca2+ signaling between sexes, dehydration, and hyperglycemic models. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Impact of a 16-week strength training program on physical performance, body composition and cardiac remodeling in previously untrained women and men.

Even if more and more women are involved in strength-training (ST) programs in fitness centers, studies on strength gain, body composition, and cardiac remodeling were mainly conducted in men and whether they are similar in women remains to be explored. In this context, the aim of our study was to assess the effect of a supervised ST program on strength gains, body composition, and cardiac remodeling in previously untrained women and men. 17 healthy and previously untrained young women and 17 young men participated in a supervised 16-week ST program built according to the recommendation of the American College of Sports Medicine in terms of intensity, and strictly using similar volume and intensity in both groups. Strength performance, body composition, and cardiac remodeling were evaluated every 4weeks. Cardiac adaptations were assessed using resting echocardiography, including regional 2D-Strain analysis of the left atrium and ventricle (LA and LV, respectively). Despite lower values at baseline, women exhibited similar or even higher strength gains compared to men. ST induced a decrease of body and abdominal fat mass and an increase of lean body mass in both groups. Similar cardiac remodeling was observed in women, and women, including an early and progressive LV and LA enlargement throughout the ST program, without any alteration of LV diastolic and systolic functions. These findings underlie that ST programs are highly suitable for women to enhance their strength performance and their cardiovascular health.

HEART RATE VARIABILITY DURING PHYSICAL EFFORT IN PATIENTS WITH METASTATIC OVARIAN CANCER AND CONCOMITANT OBESITY

Introduction. One of the main factors affecting postoperative outcomes in patients with advanced ovarian cancer is the cardiopulmonary status. Several studies have reported that preoperative multifactorial rehabilitation and physical fitness can lead to reduced postoperative morbidity, mortality, shorter length of stay, and improved quality of life in cancer patients. The issue of adaptability to physical activity of overweight and obese patients who undergoing debulking surgery is insufficiently studied. The study of compensatory changes that occur in physically inactive obese patients remains relevant, especially against the background of neoadjuvant chemotherapy, in the conditions of preoperative preparation with ERAS-recommended physical activity.&#x0D; The aim of the study is to determine the differences between women with advanced ovarian cancer and obesity compared to women with normal weight in terms of heart rate variability during exercise. To assess the adaptive capabilities to physical activity of patients with advanced ovarian cancer and obesity at the stage of preoperative preparation, who undergoing debulking surgery.&#x0D; Result. Achieved METs, peak HR, CI, and HR recovery were higher in nonobese women, whereas training had no significant effect in obese women. Women who had already received neoadjuvant CT achieved a lower level of MET (6.8 ± 3.2 vs. 8.9 ± 4.1; P &lt; 0.001). Also, peak HR and CI were lower in women after neoadjuvant CT (126±27 vs. 138±20; P = 0.001 and 0.65±0.22 vs. 0.71±0.22; P = 0.001, respectively). BMI was a significant predictor of exercise capacity only in the obese subgroup, whereas age, peak HR, and prior adjuvant HT were always significantly associated with METs achieved.&#x0D; Conclusions. No significant difference was found between trained and untrained women with comorbid obesity in HR behavior or physical capacity. Different heart rate behavior in patients of this group is thus explained by obesity as such, regardless of the degree of physical training.

The relevance of body composition assessment for the rating of perceived exertion in trained and untrained women and men.

Introduction: Mechanic power output (MPO) and oxygen consumption (VO2) reflect endurance capacity and are often stated relative to body mass (BM) but less often per skeletal muscle mass (SMM). Rating of perceived exertion (RPE) has previously shown conflicting results between sexes at submaximal intensities. Individual body composition, however, largely differs due to sex and training status. It was the aim of this study to evaluate RPE of untrained and trained individuals of both sexes considering body composition and to estimate whether RPE could be improved as a tool to determine endurance capacity. Methods: The study included 34 untrained adults (age 26.18 ± 6.34years, 18 women) and 29 endurance trained (age 27.86 ± 5.19, 14 women) who were measured for body composition (InBody 770, InBody Europe B.V., Germany) and tested on a treadmill (Pulsar, H/P/Cosmos, Germany) for aerobic capacity (Metalyzer 3B, Cortex Biophysik GmbH, Germany) in an all-out exercise test applying the Bruce-protocol. VO2, MPO, heart rate (HR), and RPE were obtained at each exercise stage. VO2 and MPO were calculated per BM and SMM. RPE values were correlated with absolute VO2 and MPO, as well as relative to BM, and SMM. HR values and the parameters' standardized values served for comparison to standard procedures. Results: VO2 and MPO were higher in men compared to women and in trained compared to untrained participants. No differences between groups and sexes exist when VO2 and MPO were calculated per BM. When calculated per SMM, VO2 and MPO indicate opposite results already at low intensity stages of exercise test. RPE values had highest correlation with MPO per SMM (R2 = 0.8345) compared to absolute MPO (R2 = 0.7609), or MPO per BM (R2 = 0.8176). Agreement between RPE and MPO per SMM was greater than between RPE and HR (p = 0.008). Conclusion: Although RPE represents a subjective value at first glance, it was shown that RPE constitutes a valuable tool to estimate endurance capacity, which can be further enhanced if individual body composition is considered. Furthermore, MPO and VO2 should be considered relative to SMM. These findings might help to avoid over-exertion, especially among untrained people, by adjusting the training intensity for each subject according to the individual strain evaluated in an exercise test based on individual body composition.

Can infrared thermography serve as an alternative to assess cumulative fatigue in women?

Muscle fatigue can limit performance both in sports and daily life activities. Consecutive days of exercise without a proper recovery time may elicit cumulative fatigue. Although it has been speculated that skin temperature could serve as an indirect indicator of exercise-induced adaptations, it is unclear if skin temperature measured by infrared thermography (IRT) could be an outcome related to the effects of cumulative fatigue. In this study, we recruited 21 untrained women and induced cumulative fatigue in biceps brachii over two consecutive days of exercise. We measured delayed onset muscle soreness (DOMS, using a numeric rate scale), maximal strength (using a dynamometer), and skin temperature (using IRT) in exercise and non-exercise muscles. Cumulative fatigue reduced muscle strength and increased DOMS. Skin temperature in the arm submitted to cumulative fatigue was higher for minimum and mean temperature, being asymmetrical in relation to the control arm. We also observed that the variations in the minimum and mean temperatures correlated with the strength losses. In summary, skin temperature measured by IRT seems promising to help detect cumulative fatigue in untrained women, being useful to explain strength losses. Future studies should provide additional evidence for the potential applications not only in trained participants but also in patients that may not be able to report outcomes of scales or precisely report DOMS.

Effects of Whole-Body Vibrotherapy on Selected Parameters of Body Composition and Subjectively Perceived Quality of Life in Young Women

Introduction: Overweightness and obesity are a very worrying and growing health problem. Medical science is increasingly looking for effective ways to combat the effects of the disease, not only at the level of physical health, but also in other dimensions of human health, such as mental health and social function. A promising form of therapy in this area is vibration therapy.Research objectives: The aim of the work was to evaluate the influence of whole-body vibrotherapy on selected parameters of body composition and subjectively perceived quality of life in young women.Materials and methods: The research was a pilot study. The study involved 22 women. Before and after 30 minutes of daily vibrotherapeutic treatment for a period of 4 weeks, body composition was measured with the Tanita analyser, which uses innovative electric bioimpedance technology (BIA). In addition, the participants completed the Short-Form Health Survey (SF-36) questionnaire on quality of life assessment before and after a series of vibrotherapy sessions.Results: After a series of systemic vibrotherapies, lower average body mass index, fat %, fat mass, BMI, VFR, FFM and BMR values of the women studied were achieved than before the series. The decrease in indicators was shown to be associated with vibrotherapy, as the study group included healthy, untrained and non-dietary women. Of particular significance is the decrease in BMI and VFR, which was important in view of the short investigation period. The TBW and TBW rates increased slightly, which can also be classified as positive effects of the therapy. The subjective assessment of quality of life was not significantly changed in the study group, apart from the area of well-being, which showed a slight improvement in 54% (12 women in the 22-person group).Conclusion: Oscillatory-cycloidal vibrotherapy can be an effective tool to normalise the level of body composition parameters and to combat obesity. The positive effect of vibrotherapy on subjectively perceived quality of life among the subjects is also indicated.

Does Obesity Affect Neuromuscular and Cardiovascular Adaptations after a 3-Month Combined Exercise Program in Untrained Premenopausal Middle-Aged Women?

Previous studies indicated different acute adaptations between obese and lean individuals, while there is limited information with conflicting results regarding long-term adaptations. The aim of this study was to compare the efficacy of a 3-month integrated combined training between obese and lean middle-aged untrained premenopausal women. In total, 72 women (36 obese/36 lean) were divided into four groups: (a) obese exercise (OB-EG), (b) obese control (OB-CG), (c) lean exercise (L-EG), and (d) lean control (L-CG). The exercise groups followed a 3-month (3 times/week) integrated combined aerobic and strength training program. Health indices (body composition, body circumferences, blood pressure, respiratory function), functional capacity (flexibility, balance), and physical fitness (strength, aerobic capacity) were measured before and after the 3-month time period. Participants' enjoyment was also assessed following the program. OB-EG and L-EG significantly improved (p < 0.05) similarly across all functional capacity and physical fitness indices (10-76%; depending on the evaluation index), except balance and strength indices of the non-preferred limb where OB-EG showed greater improvement (reducing the existing pre-training strength/balance asymmetries) than L-EG. Furthermore, both obese and lean individuals showed similarly high levels of enjoyment. This program could be effectively used in fitness settings causing similar neuromuscular and cardiovascular adaptations in obese and lean women.

75-repetition versus sets to failure of blood flow restriction exercise on indices of muscle damage in women

ABSTRACT There is conflicting evidence regarding the prevalence and magnitude of exercise-induced muscle damage (EIMD) following low-load resistance exercise with blood flow restriction (LL + BFR) that may be related to exercise protocols. The purpose of this investigation was to examine the effects of 75-repetition (BFR-75) (1 × 30, 3 × 15) and 4 sets to failure (BFR-4x) protocols on indices of EIMD among untrained women. Thirteen women completed this investigation. One leg was randomly assigned to BFR-75 and the other to BFR-4x. Each leg performed isokinetic, unilateral, concentric-eccentric, leg extension muscle actions at 30% of maximal strength. Indices of EIMD (muscle soreness, range of motion [ROM], limb circumference, pain pressure threshold [PPT], and maximal voluntary isometric contraction [MVIC]) were recorded before exercise, 0-, 24-, 48-, 72-, and 96-hours post-exercise. There were no changes for ROM, circumference, or PPT. Muscle soreness increased similarly in both conditions 0-, 24-, and 48-hours post-exercise and MVIC increased 24-, 48-, 72-, and 96-hours post-exercise. These findings suggested BFR-75 and BFR-4x were not associated with EIMD and elicited similar physiological responses. The increases in muscle soreness may be due to metabolic stress associated with LL + BFR protocols apart from EIMD.

Accuracy of Predicted Intraset Repetitions in Reserve (RIR) in Single- and Multi-Joint Resistance Exercises Among Trained and Untrained Men and Women.

We assessed the accuracy of intraset repetitions in reserve (RIR) predictions on single-joint machine-based movements of trained and untrained men and women. Participants were 27 men (M age = 22, SE = 0.6 years; M weight = 90.8, SE = 4.0kg; M height = 182.3, SE = 1.4cm; M training experience = 66, SE = 9 months) and 31 women (M age = 20, SE = 0.4 years; M weight = 67.8, SE = 2.3kg; M height = 167.6, SE = 1.1cm; M training experience = 22, SE = 4 months). In one session, participants performed a five-repetition maximum (5RM) test on biceps curl, triceps pushdown, and seated row exercises; we then estimated one repetition maximum (1RM). Participants then performed four sets of each exercise, in a randomized order, to the point of momentary muscular failure at 72.5% of 1RM. During each set, participants indicated when they first perceived 5RIR and then predicted RIR on every repetition thereafter until failure. The difference between actual repetitions performed and predicted repetitions at each intraset prediction was determined to be the RIR difference (RIRDIFF). A 3-way repeated measures ANCOVA found that a 3-way interaction was not statistically significant (p = 0.435) and no covariates of sex (p = 0.917), training experience (p = 0.462) nor experience rating RIR significantly affected RIRDIFF (p = 0.462-0.917). There were significant main effects for the proximity to failure of the prediction and the set number (p < 0.01) but not for exercise (p = 0.688). Thus, intraset RIR predictions were more accurate when closer to failure and in later sets, but sex, training experience, and experience rating RIR did not significantly influence RIR prediction accuracy on machine-based single-joint exercises.

The Effect of Strawberry Extract Supplementation on Caspase -3 and Cytochrome C After Resistance Exercise in Non-athletic Women

Background: Exercise-induced apoptosis occurs in a variety of tissues. Objectives: This study aimed to determine the effects of strawberry extract supplementation on circulating apoptosis biomarkers following a single bout of resistance exercise. Methods: Eighteen healthy young untrained women were enrolled in a randomized, double-blind, placebo-controlled crossover research. The subjects participated in one resistance exercise session (at 80% 1RM) and underwent 2 wk strawberry extracts (700 mg daily) or maltodextrin. The washout period that separated the treatment periods was 4 wk. Blood samples were taken before supplementation and after 2 wk of the post-resistance exercise session to determine cytochrome c and caspase-3 serum markers. Results: Resting cytochrome c and caspase-3 concentrations were not significantly different for any strawberry extract supplementation and placebo groups (P &gt; 0.05). Cytochrome c and caspase-3 were significantly elevated after exercise in a placebo (P &lt; 0.05) but not strawberry extract supplementation. Conclusions: Supplementation with strawberry extract attenuates intense acute exercise-induced apoptosis in healthy women.

Effects of Microfiltered Seawater Intake and Variable Resistance Training on Strength, Bone Health, Body Composition, and Quality of Life in Older Women: A 32-Week Randomized, Double-Blinded, Placebo-Controlled Trial

The aim was to explore the effects of a 32-week resistance training (RT) intervention with elastic bands with or without microfiltered seawater (SW) supplementation on isokinetic strength, bone mineral density (BMD), body composition, and subjective quality of life in postmenopausal women. Ninety-three untrained women (age: 70.00 ± 6.26 years; body mass index: 22.05 ± 3.20 kg/m2; body fat: 37.77 ± 6.38%; 6.66 ± 1.01 s up-and-go test) voluntarily participated in this randomized, double-blinded, controlled trial. Participants were allocated into four groups (RT+SW, RT+PLA, CON+SW, and CON+PLA). The RT intervention (twice weekly) consisted of different exercises for the whole body performed at submaximal intensities with elastic bands. Both control groups were not involved in any exercise program. A two-way mixed analysis of variance of repeated measures revealed significant improvements in almost all the variables in both intervention groups (p < 0.05). However, significant differences with controls were encountered in isokinetic strength, body fat percentage, and bodily pain. Although the group with SW supplementation obtained greater effect sizes, non-significant differences between both RT groups were observed. In conclusion, the determinant factor of the adaptations seems to be RT rather than SW.

Calf blood flow is augmented in habitually aerobically trained versus untrained postmenopausal women in association with favorable modulation of vasculo-metabolic interactions.

Menopause is associated with vascular dysfunction and increased risk of developing metabolic syndrome. Associations between vascular and metabolic health, and interactions with aerobic exercise training, are unknown in postmenopausal women (PMW). In habitually aerobically trained PMW (PMWtr; n= 10; 57 ± 1 years; 40 ± 1mL/kg/min), strain-gauge plethysmography was used to compare resting and peak calf blood flow (CBFr and CBFpk, respectively) and vascular resistance (CVRr; CVRpk) versus untrained PMW (PMWun; n= 13; 56 ± 1 years; 29 ± 1mL/kg/min) and premenopausal women (PreM; n= 14; 26 ± 1 years; 40 ± 1mL/kg/min). Vascular measures were taken before and 1 hour after 45 minutes of aerobic exercise (60% V̇ O2peak ), a known nitric oxide stimulus. Blood analyses included low- (LDLc) and high-density lipoprotein cholesterol (HDLc), insulin, and glucose. Pre-exercise, CBFr and CVRr did not differ (p> 0.05) between PMW groups, nor between PreM and PMWtr. CBFpk was highest (p< 0.05) and CVRpk was lowest (p< 0.05) in PMWtr. Blood markers were similar (p> 0.05) in PMW groups. However, in PMWtr, CBFpk was associated inversely (p< 0.05) with insulin (r= -0.725). Conversely, in PMWun, CBFpk correlated (p< 0.05) inversely with glucose (r= -0.717), positively with HDLc (r= 0.633), and CVRpk positively (p< 0.05) with LDLc (r= 0.568). Post-exercise, CBF increased and CVR decreased (p< 0.05) in all groups, yet CBFpk remained higher and CVRpk lower (p< 0.05) in PMWtr. In untrained PMW, peak CBF is associated inversely with circulating pro-atherogenic lipids and glucose. In contrast, peak CBF is associated inversely with insulin levels only in trained PMW. Habitual aerobic exercise may favorably modulate vasculo-metabolic interactions in PMW.