Performed Resistance Training Research Articles

Moderate and Higher Protein Intakes Promote Superior Body Recomposition in Older Women Performing Resistance Training.

Resistance training (RT) combined with appropriate dietary intake can promote a concomitant increase in skeletal muscle mass (SMM) and reduction in fat mass, a condition termed body recomposition. This study's primary purpose was to explore the effects of protein ingestion on body recomposition after 24 wk of RT in older women. Data from 130 untrained older women (68.7 ± 5.6 yr, 66.5 ± 11.5 kg, 155.5 ± 6.0 cm, and 27.4 ± 4.0 kg·m-2) across six studies were retrospectively analyzed. The participants were divided into tertiles according to their customary protein intake (g·kg-1·d-1): lower (LP; n = 45), moderate (MP; n = 42), and higher (HP; n = 43) protein intake. Participants performed a whole-body RT program carried out over 24 wk (eight exercises, three sets, 8-15 repetitions, three sessions a week). SMM and fat mass were determined by dual-energy x-ray absorptiometry. All groups increased SMM from baseline (P < 0.05), with the HP and MP groups showing greater increases than the LP group (LP, 2.3%; MP, 5.4%; and HP, 5.1%; P < 0.05). Reductions in fat mass were similar for all three groups (LP, 1.7%; MP, 3.7%; and HP, 3.1%; P > 0.05). The composite z-score of the percentage changes from pretraining to posttraining indicated greater positive body recomposition values for HP and MP compared with LP (P < 0.05). Results suggest that protein intake is a moderating variable for body recomposition in older women undergoing RT, with a low protein intake having a less favorable effect on body recomposition.

Sedentary postmenopausal women not undergoing hormone replacement therapy can have their blood pressure lowered by performing resistance training: a systematic review and meta-analysis of randomized controlled trials

Aim: This systematic review and meta-analysis aimed at examining the literature regarding the effects of resistance training (RT) on blood pressure (BP) in postmenopausal women. Methods: The Pubmed, Scopus, Embase, and BVS databases were accessed by two independent reviewers between July 2020, and June 2021 to search for studies that investigated the effects of RT on BP. The eligibility criteria were determined by the PICOT strategy. P: postmenopausal women, I: RT, in which training variables are presented, C: presence of a control group that does not receive any type of intervention, O: BP measured in both groups, at least before and after the intervention, T: randomized controlled trial. For the studies included in the meta-analysis, we calculated the effects sizes based on the net changes in the systolic (SBP) and diastolic (DBP) BP for a random effect model with a confidence interval of 95% and a statistical significance of p < 0.05. Results: The RT group presented a significantly lower SBP (−7.25 mmHg [95% CI: −14.04, −0.45], p = 0.04), while DBP was not statistically significantly different compared to controlled conditions (−2.54 mmHg [95% CI: −5.52, 0.44], p = 0.09). Conclusions: Physically-inactive postmenopausal women who did not take hormone replacement but performed RT exercise had a lower BP value when compared to the control group.

Acute caffeine and capsaicin supplementation and performance in resistance training

Aim: This study aimed to evaluate the acute supplementation effects of capsaicin, caffeine, and the combined capsaicin plus caffeine on total volume (total repetitions x weight lifted), rate of perceived exertion (RPE), and side-effects on resistance training. Methods: Eleven men (21.5 ± 2.1 years, 1.75 ± 0.08 m, 79.64 ± 10.1 kg), trained in resistance training (experience of 4.5 ± 2.6 years, weekly frequency 5 ± 0.8 days) were recruited. This was a crossover, randomized, double-blind study. Each volunteer went through four experimental conditions: supplemented with capsaicin (12 mg), caffeine (400 mg), capsaicin plus caffeine (12 mg and 400 mg, respectively), or placebo. After supplementation, the volunteers completed four sets of back squats until failure, at 70% of one-repetition maximum, with 90 s of rest interval between sets. RPE was registered at the end of each set. Volunteers were asked about the occurrence of side effects, right after exercise and 24 h after supplementation. Results: No significant differences were found (p > 0.05) in total volume between placebo (5505.2 ± 810.7 kg), capsaicin (6010.0 ± 1067.0 kg), capsaicin plus caffeine (5885.1 ± 1219.3 kg), and Caffeine (5628.6 ± 894.4 kg). No significant differences were found in RPE (p > 0.05) between the experimental conditions. The effect size of the total volume was small in capsaicin and capsaicin plus caffeine (d = 0.62 e d = 0.47, respectively), and trivial in the caffeine condition (d = 0.15). Conclusion: The supplementation failed to influence resistance training performance as well as had no effects on increasing the total volume or reducing RPE.

A Review: Effect of Rest Interval Duration on the Volume Completed During Resistance Training

The rest duration between sets is one of the most essential resistance training variables; however, research on the effects of rest intervals between sets has shown inconsistencies on whether short or long rest intervals significantly increase overall performance during resistance training. This literature review aimed to investigate how different rest intervals between sets affect the maintenance of repetitions, training volume, and overall strength gains from resistance exercises in both trained and non-trained individuals. Fifteen original investigations and three textbooks involving the effect of between set rest intervals during resistance training are summarized in this review. The results for the studies interested in repetition maintenance suggested longer rest intervals significantly increased the number of repetitions and helped repetitions stay more consistent throughout sets. Longer rest intervals were also determined to increase training volume but had no significant effect on overall strength gains. Biochemical substrates that provide the catalyst for energy creation can take up to eight minutes to fully resynthesize; therefore, more research is needed on longer rest intervals to see if there are further increases in resistance training performance.

Dose Response of Acute ATP Supplementation on Strength Training Performance.

Background: Chronic oral ATP supplementation benefits cardiovascular health, muscular performance, body composition, and recovery while attenuating muscle breakdown and fatigue. A single 400 mg dose of oral ATP supplementation improved lower body resistance training performance and energy expenditure in recreational resistance trained males, however, the minimal effective dose is currently unknown.Materials and Methods: Twenty recreationally trained men (age 28.6 ± 1.0 years, body mass 81.2 ± 2.0 kg, height 175.2 ± 1.4 cm, 1RM 141.5 ± 5.0 kg) consumed a single dose of either 400 mg, 200 mg, or 100 mg ATP (PEAK ATP®, TSI USA LLC, Missoula, MT, USA) or a placebo in a randomized, placebo-controlled crossover design, separated by a one week wash out between treatments. After warm-up, participants performed 4 sets of half-squats using free-weights until movement failure separated by 2 mins of rest between sets.Results: In comparison to placebo, 400 mg ATP significantly increased the number of set 1 repetitions (+13%, p = 0.04), and numerically increased total repetitions (+7%, p = 0.19) and total weight lifted (+6%, p = 0.22). 200 mg ATP numerically increased set 1 repetitions (+4% p = 0.47), while 100 mg ATP showed no improvements over placebo. 100 mg ATP (−4%, p < 0.05) and 400 mg ATP (−4%, p = 0.11) decreased the perceived rate of exertion compared to placebo.Conclusions: In this study, the effective minimal dose of acute oral ATP supplementation during resistance exercise to increase performance was determined to be 400 mg, while as little as 100 mg showed improvements in perceived exertion.

Resistance training mitigates hepato-cardiac changes and muscle mitochondrial protein reductions in rats with diet-induced obesity

AimTo investigate the effect of resistance training (RT) on hepatocardiovascular and muscle mitochondrial parameters in rats that were fed a high-calorie diet for 12 weeks. Main methodsThe animals were divided into four groups: control (C), exercise (E), obese (O), and obese plus exercise (OE). Group E and OE rats performed resistance training by climbing on a vertical ladder with load attached to the end of the tail (1×/day, 3×/week, for 12 weeks). Group O and OE rats were fed a high-calorie diet containing chow and a cafeteria diet for 12 weeks. Under anesthesia, the heart and liver were removed for histopathological analysis, and the gastrocnemius muscle was removed for Western blotting. Key findingsGroup O rats were heavier, with increased fat mass, elevated fasting glycemia, and total triglycerides, and exhibited a significant number of Kupffer cells and diffuse steatosis in the liver. Group O rats also showed increased thickness of the right ventricle, septum, and pulmonary artery. All of these parameters were attenuated by RT. PGC1-α protein levels were increased in both exercise groups. The protein levels of OXPHOS complexes III, IV, and V were reduced in Group O, while RT prevented this alteration. SignificanceRT exerts a protective effect against hepato-cardiac alterations and prevents changes in the muscle mitochondrial protein profile induced by a high-calorie diet.

The Effect of Whole Egg Intake on Muscle Mass: Are the Yolk and Its Nutrients Important?

Whole egg may have potential benefits for enhancing muscle mass, independent of its protein content. The yolk comprises ∼40% of the total protein in an egg, as well as containing several nonprotein nutrients that could possess anabolic properties (e.g.,microRNAs, vitamins, minerals, lipids, phosphatidic acid and other phospholipids). Therefore, the purpose of this narrative review is to discuss the current evidence as to the possible effects of egg yolk compounds on skeletal muscle accretion beyond those of egg whites alone. The intake of whole egg seems to promote greater myofibrillar protein synthesis than egg white intake in young men. However, limited evidence shows no difference in muscle hypertrophy when comparing the consumption of whole egg versus an isonitrogenous quantity of egg white in young men performing resistance training. Although egg yolk intake seems to promote additional acute increases on myofibrillar protein synthesis, it does not seem to further enhance muscle mass when compared to egg whites when consumed as part of a high-protein dietary patterns, at least in young men. This conclusion is based on very limited evidence and more studies are needed to evaluate the effects of egg yolk (or whole eggs) intake on muscle mass not only in young men, but also in other populations such as women, older adults, and individuals with muscle wasting diseases.

High Dose of Caffeine Mouth Rinse Increases Resistance Training Performance in Men.

Caffeine mouth rinsing (CMR) has been shown to enhance exercise performance. However, no studies have analyzed the effects of different dosages of CMR on muscular performance. Therefore, the purpose of this study was to examine the effects of different dosages of CMR on strength (bench press 1 repetition maximum (1-RM)) and muscular endurance (60% of 1-RM repetitions to failure) in resistance-trained males. Fourteen resistance-trained males (age: 23 ± 2 years, height: 179 ± 3 cm, body mass: 83 ± 4 kg, BMI: 17 ± 2 kg/m2) completed four conditions in random order. The four conditions consisted of a mouth rinse with 25 mL solutions containing either 1% (250 mg) of CMR (low dose of CMR: LCMR), 2% (500 mg) of CMR (moderate dose of CMR: MCMR), 3% (750 mg) of CMR (high dose of CMR: HCMR) and sweetened water (placebo: PLA) for 5 s prior to a bench press strength and muscular endurance test. Maximal strength, muscular endurance, heart rate (HR) and ratings of perceived exertion (RPE) were recorded for each condition. There were no significant differences in strength (p = 0.30) and HR (p = 0.83) between conditions. HCMR significantly increased muscular endurance performance (p = 0.01) and decreased RPE values (p = 0.01). In conclusion, CMR did not affect bench press 1-RM strength performance, but muscular endurance responses to CMR seems to be dose-dependent.

Effect of intermittent hypoxic conditioning on inflammatory biomarkers in older adults.

Ageing is associated with chronic low-grade inflammation and with a decrease in muscle mass and strength. The aim of the study was to evaluate the effect of a resistance training programme in conditions of intermittent hypoxia on inflammatory biomarkers in older people. A total of 54 older adults (aged 65-75years), who voluntarily participated in the study, were randomly divided into three groups: the control (CON) group, the resistance training normoxia (RTN) group that performed resistance training in normoxia and resistance training hypoxia (RTH) group that trained under hypoxic conditions at a simulated altitude of 2500m above sea level. The training programme that was carried out during 24weeks was similar in both experimental groups and consisted of a full-body workout with elastic bands and kettlebells (three sets x 12-15 reps). Blood inflammatory parameters (CRP, VCAM-1, IL-6, IL-8 and IL-10) were analysed before and after the intervention. After the resistance training programme, a significant decrease in CRP and IL-8 levels was observed, as well as an increase in IL-10 levels, both in normoxia and hypoxia. These results show that resistance training, either in conditions of normoxia or hypoxia, is useful to deal with the chronic inflammation associated with ageing.

Intramuscular hyaluronic acid expression following repetitive power training induced nonfunctional overreaching.

Hyaluronic acid (HA) contributes to extracellular matrix viscosity and fiber regeneration. HA role in resistance training (RT) performance adaptations is unclear. RT men performed power training (nonfunctional overreaching (NFOR) or normal training (CG)) over 7.5days. Post RT, the CG improved power while NFOR did not with HA content decreasing 34.5% in NFOR with no change in CG. HA is critical for muscular recovery; decreased HA may contribute to impaired power adaptations with NFOR RT. Novelty: Nonfunctional over-reaching decreases muscular hyaluronic acid.

Acute hemodynamic responses are not different for mono and multiarticular exercises for the same muscle group

Introduction: Different mechanical behaviors in resistance training can result in certain changes in the cardiovascular system. Objective: To verify the acute behavior of the main cardiovascular variables (heart rate, blood pressure, and double product) when performing resistance training with mono and multiarticular exercises. Methods: 10 male subjects participated in the study (26 ± 4 years; 81 ± 6 kg; 1.77 ± 2 m; 23 ± 1 kg / m2). They performed a test and retest for 8RM in the bench press and crucifix exercises on the machine. After the loads were outlined, they performed the intervention with the exercises, initially with a monoarticular activation containing two sets of 12 repetitions with 50% of the load acquired in the 8RM test of each exercise, using an interval of 60 seconds between one set and another. Additionally, three sets of 8 repetitions (80% 8RM) were performed with an interval between sets of 120 seconds. The execution speed was determined at a moderate level (2s for concentric, 2s for eccentric). It was measured before and during (series 1, series two, and series 3. Named as moments) heart rate exercises using POLAR, model RS800CX Multisport® and blood pressure using OMRON M6 (HEM-7001- E) ®. Then, the double product was calculated using the formula [HR (bpm) X SBP (mmHg)]. Results: In the heart rate analysis, there was an intra-condition difference for moments 1, 2, and 3 compared to rest (p &lt;0.000). In the inter-condition comparison, no differences were observed for rest (p = 0.994) and for moments 1, 2 and 3 (p&gt; 0.999). In systolic blood pressure, intra-conditions, differences were observed for moments 1, 2, and 3 compared to rest (p &lt;0.000). In the inter-condition comparisons, there were no differences between rest (p&gt; 0.999), moment 1 (p = 0.714), 2 (p = 0.999) and 3 (p&gt; 0.999). For diastolic blood pressure, intra conditions, for bench press no significant differences were found for moments 1 (p = 0.331), 2 (p = 0.505) and 3 (p = 0.505) when compared to rest. In the same way it was for the crucifix, wherein the comparison with rest, no difference was observed in moments 1 (p = 0.849), 2 (p = 0.195) and 3 (p = 0.105). In the same sense, no difference was also observed in the comparisons between conditions for rest (p&gt; 0.999), moment 1 (p = 0.999), 2 (p = 0.989) and 3 (p = 0.948). Finally, the double product in intra-condition comparisons found differences between moments 1, 2, and 3 compared to rest (p &lt;0.000). However, in the inter-condition comparisons, no difference was observed at rest (p = 0.999), moment 1 (p = 0.868), 2 and 3 (p&gt; 0.999). Conclusion: It is suggested that resistance training composed of mono and multi-joint exercises offers differences in hemodynamic responses but without differences between the types of mechanics applied by the exercises. Therefore, these results offer a partiality of what can happen with heart rate, blood pressure, and double product.

Effects of Short-Term Golden Root Extract (Rhodiola rosea) Supplementation on Resistance Exercise Performance.

The purpose of this study was to examine the effects of short-term Golden Root Extract (GRE; Rhodiola rosea) supplementation on blood lactate, catecholamines, and performance during repeated bench press exercise. Resistance-trained males (n = 10) participated in this study. In a double-blinded, crossover, counterbalanced study design, participants supplemented with either 1500 mg/day of GRE or placebo (PL; gluten-free cornstarch) for 3 days prior to experimentation. An additional 500 mg dose was ingested 30 min prior to exercise testing. During each exercise trial, participants completed 2 repetitions of bench press at 75% of one-repetition maximum (1RM) as explosively as possible. A linear position transducer was used to measure mean concentric velocity. After 5 min of rest, participants completed 3 sets × repetitions to failure (RTF) at 75% 1RM separated by 2 min of rest between each set. A capillary blood sample was obtained pre- (PRE) and immediately post- (POST) exercise to measure blood concentrations lactate (LA), epinephrine (EPI), and norepinephrine (NE). Mean concentric velocity was significantly higher with GRE when compared to PL (p = 0.046). However, total RTF were significantly lower with GRE versus PL (p < 0.001). Regardless of treatment, LA was significantly higher Post versus Pre (p < 0.001), but GRE resulted in greater Post values compared to PL (p = 0.049). EPI and NE increased in both conditions Pre to Post (p < 0.001). However, Pre NE was significantly higher with GRE versus PL (p = 0.008). Findings indicate that short-term GRE supplementation increases mean bench press velocity but decreases bench press repetition volume. Furthermore, GRE resulted in higher NE levels and blood lactate following exercise. Thus, supplementing with GRE may enhance explosive resistance training performance but may also impair upper body strength-endurance.

Physical Activity Level Following Resistance Training in Community-Dwelling Older Adults Receiving Home Care: Results from a Cluster-Randomized Controlled Trial.

Older adults’ physical activity (PA) is low. We examined whether eight months of resistance training increased PA level in community-dwelling older adults receiving home care. A two-armed cluster-randomized trial using parallel groups was conducted. The included participants were >70 years and received home care. The resistance training group performed resistance training using body weight, elastic bands, and water canes twice per week for eight months. The control group was informed about the national PA guidelines and received motivational talks. The ActiGraph GT3X+ accelerometer was used to estimate PA. Outcomes included total PA (counts per minute), sedentary behavior (min/day), light PA (min/day), moderate-to-vigorous PA (min/day), and steps (mean/day). Between-group differences were analyzed using multilevel linear mixed models. Twelve clusters were randomized to either resistance training (7 clusters, 60 participants) or the control group (5 clusters, 44 participants). A total of 101 participants (median age 86.0 (interquartile range 80–90) years) had valid accelerometer data and were included in the analysis. There were no statistically significant between-group differences for any of the PA outcomes after four or eight months. This study offers no evidence of increased PA level following resistance training in older adults with home care.

High-Protein Energy-Restriction: Effects on Body Composition, Contractile Properties, Mood, and Sleep in Active Young College Students.

Background: It is often advised to ensure a high-protein intake during energy-restricted diets. However, it is unclear whether a high-protein intake is able to maintain muscle mass and contractility in the absence of resistance training.Materials and Methods: After 1 week of body mass maintenance (45 kcal/kg), 28 male college students not performing resistance training were randomized to either the energy-restricted (ER, 30 kcal/kg, n = 14) or the eucaloric control group (CG, 45 kcal/kg, n = 14) for 6 weeks. Both groups had their protein intake matched at 2.8 g/kg fat-free-mass and continued their habitual training throughout the study. Body composition was assessed weekly using multifrequency bioelectrical impedance analysis. Contractile properties of the m. rectus femoris were examined with Tensiomyography and MyotonPRO at weeks 1, 3, and 5 along with sleep (PSQI) and mood (POMS).Results: The ER group revealed greater reductions in body mass (Δ −3.22 kg vs. Δ 1.90 kg, p < 0.001, partial η2 = 0.360), lean body mass (Δ −1.49 kg vs. Δ 0.68 kg, p < 0.001, partial η2 = 0.152), body cell mass (Δ −0.85 kg vs. Δ 0.59 kg, p < 0.001, partial η2 = 0.181), intracellular water (Δ −0.58 l vs. Δ 0.55 l, p < 0.001, partial η2 = 0.445) and body fat percentage (Δ −1.74% vs. Δ 1.22%, p < 0.001, partial η2 = 433) compared to the CG. Contractile properties, sleep onset, sleep duration as well as depression, fatigue and hostility did not change (p > 0.05). The PSQI score (Δ −1.43 vs. Δ −0.64, p = 0.006, partial η2 = 0.176) and vigor (Δ −2.79 vs. Δ −4.71, p = 0.040, partial η2 = 0.116) decreased significantly in the ER group and the CG, respectively.Discussion: The present data show that a high-protein intake alone was not able to prevent lean mass loss associated with a 6-week moderate energy restriction in college students. Notably, it is unknown whether protein intake at 2.8 g/kg fat-free-mass prevented larger decreases in lean body mass. Muscle contractility was not negatively altered by this form of energy restriction. Sleep quality improved in both groups. Whether these advantages are due to the high-protein intake cannot be clarified and warrants further study. Although vigor was negatively affected in both groups, other mood parameters did not change.

Anti-Apoptotic Effects of Resistance Training and Tribulus Terrestris Consumption in the Heart Tissue of Rats Exposed to Stanozolol.

Nowadays, the use of energetic substances has become a complex problem in sports, such that the role of anabolic-androgenic steroids is undeniable. This study aimed to investigate the antiapoptotic effect of resistance training and Tribulus terrestris in the heart tissue of rats exposed to stanozolol. 35 rats divided into 7 groups including (1) sham, (2) stanozolol-treated, (3) stanozolol+50 mg/kg Tribulus terrestris-treated, (4) stanozolol+100 mg/kg Tribulus terrestris-treated, (5) stanozolol+resistance training-treated, (6) stanozolol+resistance training+50 mg/kg Tribulus terrestris-treated, and (7) stanozolol+resistance training+100 mg/kg Tribulus terrestris-treated. During 8 weeks, groups 2-7 received 5 mg/kg stanozolol per day peritoneally; groups 5-7 performed resistance training for 3 sessions per week; and groups 3, 4, 6 and 7 received daily doses of Tribulus terrestris peritoneally. Stanozolol administration significantly increased the BAX, BCL-2, P53, and caspase 3 and BAX/BCL-2 ratio (P < .001). Resistance training, 100 mg/kg Tribulus terrestris administration, 50 mg/kg Tribulus terrestris administration, resistance training+100 mg/kg Tribulus terrestris administration, and resistance training+50 mg/kg Tribulus terrestris administration significantly decreased BAX, BCL-2, P53, and caspase 3 levels and BAX/BCL-2 ratio (P < .001); however, stanozolol+resistance training+100 mg/kg Tribulus terrestris administration caused more decrease than stanozolol+resistance training+50 mg/kg Tribulus terrestris administration in BAX (P < .001). Resistance training and Tribulus terrestris administration alone appear to have antiapoptotic effects; however, resistance training combined with Tribulus terrestris administration, especially at higher doses, have more desirable effects than resistance training or Tribulus terrestris administration alone on the apoptosis markers.

Effects of resistance training on exercise ability in chronic obstructive pulmonary disease subjects: A systematic review and meta-analysis.

The resistance exercise effect on the exercise ability in chronic obstructive pulmonary disease (COPD) subjects has drawn considerable attention. However, the relationship between resistance exercise and the exercise ability of COPD subjects is conflicting. This meta-analysis was performed to evaluate this relationship. A systematic-literature search up to July 2020 was performed in OVID, Embase, Cochrane Library, PubMed, Google scholar for randomised control trials reported relationships between resistance exercise and the exercise ability of COPD subjects, and 13 studies were detected with 1286 subjects at the baseline. Mean differences (MD) with 95% confidence intervals (CIs) were calculated comparing the resistance exercise and the exercise ability of COPD subjects using the continuous method with a random or fixed-effect model. A significantly higher 6-minutes walk test was observed in subjects performing resistance training (MD, 60.41; 95% CI, 39.97-80.85, P<.001) compared with non-resistance training subjects. However, no significant difference was observed between COPD subjects performing resistance exercise compared with non-resistance training COPD subjects in constant work rate cycle endurance test (MD, 1.59; 95% CI, 0.03-3.15, P=.05), unsupported upper extremity exercise test (MD, 48.77; 95% CI, -1.20 to 98.75, P<.06) and quality of life questionnaires (MD, -0.62; 95% CI, -2.49 to 1.245, P<.51). The resistance exercise significantly increases the 6-minutes walk test in COPD subjects. However, resistance exercise did not significantly affect the constant work rate cycle endurance test, unsupported upper extremity exercise test and quality of life questionnaires. This relationship forces us to recommend the resistance exercise to improve the 6-minutes walk test as a simple and easy evaluation of functional exercise ability in COPD subjects.

Microcirculatory Responses to Muscle and Tendon Exercises in Individuals With and Without Type 2 Diabetes Mellitus and the Association Between Microcirculatory and Exercise Performance.

Background: This study aimed to measure and compare (1) the microcirculation and microcirculatory responses of the muscles and tendons at rest and during isometric muscle contractions in participants with and without diabetes mellitus (DM) and (2) to determine correlations between microcirculation and muscle strength. Methods: Sixty-three participants with type 2 DM and 42 physically matched controls were recruited. Baseline measurements of the microcirculation of the rectus femoris (RF) and medial gastrocnemius (MG) muscles and patellar (PT) and Achilles tendons (AT), as well as their microcirculatory changes during maximal isometric exercises, were performed and recorded by using near-infrared spectroscopy and a red laser. Data on various laboratory tests (including glycated hemoglobin, triglyceride, high-density cholesterol), the monofilament test, and the ankle-brachial index were also obtained. Results: The baseline measurements indicated that, compared with the controls, the diabetic participants had lower oxygen saturation (SpO2) in their RF and MG muscles (both P < 0.001), and the total hemoglobin in the diabetic PT and AT was higher (P = 0.001 and P = 0.01). The minimal SpO2 levels in the aforementioned muscles during isometric contractions were lower in the diabetes group than in the control group (P ≤ 0.001). Furthermore, there were correlations between the microcirculatory change of the RF muscle and the knee extension force. Conclusions: This study demonstrated the effects of diabetes on the microcirculation of skeletal muscles and tendons during baseline measurements and responses to maximal isometric exercises. The results support the need for preventive strategies for diabetic muscles to prevent adverse complications when performing resistance training.

The effect of warm-up in resistance training and strength performance: a systematic review

The warm-up is fundamental to optimize physical activity and exercise performance. However, little is known about the effect of warm-up in resistance training and strength performance. We performed a systematic review to synthesize and analyze the effects of different warm-up strategies in maximal and submaximal strength during resistance exercises. A search for studies was performed on four databases (Web of Science, Scopus, PubMed, and ScienceDirect) for original research published between May 1973 and December 2019. Eleven articles were selected according to the inclusion criteria. Most of the studies evaluated the effects of warm-up on maximal strength and the number of repetitions until failure. The results were not consensual regarding the use of general warm-up followed by a specific warm-up. Moreover, while some studies showed that specific warm-up did not lead to different results than without warm-up, others found that performing only the specific warm-up was the best way to obtain maximal strength performance. It seemed that the maximal strength and the number of repetitions could be positively affected when a specific warm-up is performed at loads close to the maximum. Further studies are needed to deepen the knowledge about the preparation procedures for optimizing resistance exercise performances. Keywords: pre-exercise, general warm-up, specific warm-up, strength, performance.

Effects of high-intensity interval training combined with traditional strength or power training on functionality and physical fitness in healthy older men: A randomized controlled trial.

Concurrent training (CT) is an efficient strategy to improve neuromuscular function and cardiorespiratory fitness in older adults, which are factors of pivotal importance for the maintenance of functional capacity with aging. However, there is a lack of evidence about the effectiveness of power training (PT) as an alternative to traditional strength training (TST) during CT. Thus, the aim of the present study was to examine the effect of 16weeks (twice weekly) TST combined with high intensity interval training (TST+HIIT) vs. PT combined with HIIT (PT+HIIT) on functional performance, cardiorespiratory fitness and body composition in older men. Thirty five older men (65.8±3.9years) were randomly allocated into two training groups: TST+HIIT (n=18), and PT+HIIT (n=17). TST+HIIT performed resistance training at intensities ranging from 65% to 80% 1RM at slow controlled speed (≅ 2s for each concentric phase), whereas PT+HIIT trained at intensities ranging from 40% to 60% of 1RM at maximal intentional speed. Both groups performed HIIT at intensities ranging from 75 to 90% of VO2peak. Participants performed functional tests (sit-to-stand, timed-up-and-go, stair climbing); cardiopulmonary exercise testing (maximal cycling power output: Wmax, peak oxygen uptake: VO2peak, cycling economy), as well as body composition assessment (DXA) before, post 8 and post 16weeks of training. The groups improved similarly (P<0.05) with training in all functional capacity outcomes, Wmax, cycling economy, VO2peak and body composition (P<0.05). These findings suggest that HIIT based CT programs involving TST vs. PT are equally effective in improving functionality, cardiorespiratory fitness and body composition in healthy older men.

The Effects of Two Different Intensities of Combined Training on C1q/TNF-Related Protein 3 (CTRP3) and Insulin Resistance in Women with Non-alcoholic Fatty Liver Disease

Background: C1q/TNF-related protein (CTRP3) is a potent anti-inflammatory adipokine with activities, such as reduction of glucose level and inhibition of gluconeogenesis in the liver. However, the effect of exercise training on CTRP3 in patients with non-alcoholic fatty liver disease (NAFLD) remains unknown. Objectives: This study was done to investigate the effects of two different intensities of combined training on CTRP3 and insulin resistance in women with NAFLD and compare these two training patterns. Methods: Thirty-three women with NAFLD were randomly divided into three equal groups. Group 1 performed resistance training (RT), along with aerobic interval training (AIT) (2 - 5 intervals of four minutes, 70 - 75% HRmax), group 2 performed RT along with high-intensity interval training (HIIT) (8 - 13 intervals of one minute, 85 - 95% HRmax), and the control group did not participate in any training. The body composition measurements and blood sampling were carried out before and after 12 weeks of training. Data analysis was performed using repeated-measures ANOVA (α ≤ 0.05). Results: After 12 weeks, the CTRP3 level significantly increased in group 1 compared with the control group (P = 0.01) and group 2 (P &lt; 0.001). The fasting glucose and fasting insulin levels significantly decreased in group 1 compared with the control group (P &lt; 0.001 and P = 0.01, respectively). The insulin resistance index decreased in both group 1 and group 2; however, the difference was not significant compared with the control group (P &gt; 0.05). Conclusions: Combined training (RT + AIT) in the present study increased the level of CTRP3; thus, it is likely that women with NAFLD can benefit from this program as a non-pharmacological adjunct treatment to prevent inflammation and progression of the disease.