Effect of whole-body resistance training at different load intensities on circulating inflammatory biomarkers, body fat, muscular strength, and physical performance in postmenopausal women.

The primary purpose of this study was to identify the impact of whole-body resistance training (RT) at different load intensities on adipokines, adhesion molecules, and extracellular heat shock proteins in postmenopausal women. As secondary purpose, we analyzed the impact of RT at different load intensities on body fat, muscular strength, and physical performance. Forty participants were randomized into lower-load intensity RT (LIRT, n = 20, 30-35 repetition maximum in the first set of each exercise) or higher-load intensity RT (HIRT, n = 20, 8-12 repetition maximum in the first set of each exercise). Adipokines (adiponectin and leptin), adhesion molecules (MCP-1 and ICAM-1), extracellular heat shock proteins (HO-1 and eHSP60), body fat, muscular strength (1RM), and physical performance [400-meter walking test (400-M) and 6-minute walking test (6MWT)] were analyzed at baseline and after 12-weeks RT. There was a significant time-by-group interaction for eHSP60 (P = 0.049) and 400-M (P = 0.003), indicating superiority of HIRT (d = 0.47 and 0.55). However, both groups similarly improved adiponectin, ICAM-1, HO-1, body fat, 1RM, and 6MWT (P < 0.05). Our study suggests that load intensity does not seem to determine the RT effect on several obesity-related pro-inflammatory and chemotactic compounds, body fat, 1RM, and 6MWT in postmenopausal women, although a greater improvement has been revealed for eHSP60 and 400-M in HIRT. Novelty: Higher-load intensity resistance training improves eHSP60 and 400-M in postmenopausal women. Resistance training improves the inflammatory profile, body fat, muscle strength, and 6MWT, regardless of load intensity.

Carbohydrate mouth rinse improves resistance exercise capacity in the glycogen-lowered state.

The effect of carbohydrate mouth rinse (CHO MR) on resistance exercise performance is equivocal and may be moderated by carbohydrate availability. This study determined the effect of CHO MR on low-load resistance exercise capacity completed in a fed but glycogen-lowered state. Twelve resistance-trained men (age: 22 ± 4 years; height: 1.79 ± 0.05 m; mass: 78.7 ± 7.8 kg; bench press one-repetition maximum (1RM): 87 ± 21 kg; squat 1RM: 123 ± 19 kg) completed two fed-state resistance exercise bouts consisting of six sets of bench press and six sets of squat to failure at 40% 1RM. Each bout was preceded by glycogen-depleting cycling the evening before, with feeding controlled to create acute energy deficit and maintain low muscle glycogen. During resistance exercise, participants rinsed with either a 6% CHO MR solution or a taste-matched placebo (PLA) between sets. Total volume workload was greater with CHO MR (9354 ± 2051 vs. 8525 ± 1911 kg, p = 0.010). Total number of repetitions of squat were greater with CHO MR (107 ± 26 vs. 92 ± 16, p = 0.017); the number of repetitions of bench press were not significantly different (CHO MR: 120 ± 24 vs. PLA: 115 ± 22, p = 0.146). This was independent of differences in feeling or arousal. CHO MR may be an effective ergogenic aid for athletes completing resistance exercise when in energy deficit and with low carbohydrate availability. Novelty: CHO MR can increase low-load resistance exercise capacity undertaken in a glycogen-lowered but fed state. This effect was driven by a greater number of repetitions-to-failure in the squat - using muscles lowered in glycogen content with exhaustive cycling on the evening prior to resistance exercise - but not bench press.

Effects of resistance training at different intensities of load on cross-education of muscle strength.

The objectives of this study were to 1) compare the extent of cross-transfer of muscle strength of high- versus low-load unilateral resistance training performed with external pacing of the movement (URTEP) and 2) compare the time course of the 2 approaches. Fifty subjects were randomized to 1 of the following 3 groups: G80 [2 sets at 80% and 2 sets at 40% of 1 repetition maximum (1RM), 1 concentric second and 3 eccentric seconds controlled by a metronome]; G40 (4 sets at 40% of 1RM, 1 s and 3 s controlled by a metronome); or control group. At week 1, the G80 increased the elbow flexion 1RM (P < 0.05) in contralateral arm. At week 4, both G80 and G40 increased the elbow flexion 1RM (P < 0.05) in contralateral arm. However, a greater 1RM gain was observed in the G80 than in the G40 (P < 0.05). Thus, although higher-load URTEP seems to enhance the cross-education effect when compared with lower-load URTEP, the cross-education of dynamic strength can be achieved in the 2 approaches after 4 weeks. Many patients would benefit from cross-education of muscle strength through URPEP, even those who are unable to exercise with high loads and in short periods of immobilization. Novelty: Unilateral resistance training promotes cross-education of dynamic muscle strength. However, higher-load resistance training enhances the effects of cross-education of muscle strength.

Time course of recovery is similar for the back squat, bench press, and deadlift in well-trained males.

This study examined the time course of recovery following resistance exercise sessions in the back squat, bench press, and deadlift. Twelve well-trained males (age: 24.5 ± 3.8 years, body mass: 84.01 ± 15.44 kg, training age: 7.1 ± 4.2 years) performed 4 sets to failure at 80% of a 1-repetition maximum (1RM) on the squat, bench press, and deadlift in successive weeks. The bench press was always performed in week 2 with the squat and deadlift order counterbalanced between weeks 1 and 3. Indirect muscle damage and performance fatigue was assessed immediately before and after exercise and at 24 h, 48 h, 72 h, and 96 h postexercise. Outcome measures included limb swelling, joint range of motion, delayed onset muscle soreness, average concentric velocity (ACV) at 70% of 1RM, creatine kinase, lactate dehydrogenase, and cell-free DNA (cfDNA). Most measures demonstrated a main time effect (p < 0.05) within conditions; however, no between condition (p > 0.05) differences existed. ACV decreased in the squat condition for up to 72 h (p = 0.02, -8.61%) and in the bench press (p < 0.01, -26.69%) immediately postexercise but did not decline during the deadlift condition (p > 0.05). There was a main time effect for increased cfDNA in the squat (p < 0.01) and bench press (p < 0.05), but not the deadlift (p = 0.153). Further, immediately postexercise increases in cfDNA were directly related (p < 0.05) to changes in ACV in all 3 conditions. These results suggest that the deadlift does not result in greater muscle damage and recovery time than the squat and bench press following volume-type training in well-trained men. Further, acute changes in cfDNA may predict performance during the recovery period.

Effects of order of resistance training exercises on muscle hypertrophy in young adult men.

The purpose of the present study was to analyze the effects of the order of resistance training (RT) exercises on hypertrophy in young adult men. Thirty-six young adult men (age, 21.9 ± 2.5 years; body mass, 72.6 ± 12.1 kg, height, 176.9 ± 7.4 cm; body mass index, 23.1 ± 3.3 kg/m2) were randomly assigned to 1 of 2 training groups that performed a 6-week RT program in either (i) a traditional approach starting with multi-joint (MJ) exercises followed by single-joint exercises (SJ) (MJ-SJ, n = 19) or (ii) in reverse order (SJ-MJ, n = 17). Muscle thickness of the biceps brachii and mid-thigh were assessed by ultrasound. Lean soft tissue (LST) was assessed by dual-energy X-ray absorptiometry. Both groups similarly increased (P < 0.05) biceps brachii thickness (MJ-SJ = +14.2%, SJ-MJ = +13.8%). Alternatively, only the MJ-SJ group presented an increase in mid-thigh thickness from pre- to post-training (MJ-SJ = +7.2%, SJ-MJ = +3.9%). Upper limb LSTs (MJ-SJ = +5.2%, SJ-MJ = +7.5%) were statistically similar between conditions, and a trend for significance (P = 0.07) was found for trunk LST (MJ-SJ = +7.2%, SJ-MJ = +1.7%). Nonsignificant pre- to post-training changes were observed for lower limb LSTs (MJ-SJ = +0.7%, SJ-MJ = +1.8%). Our data suggest that both sequences are effective for increasing muscle hypertrophy over a short-term RT period; there may be a potentially beneficial hypertrophic effect for the mid-thigh by performing exercises in a manner that progresses from MJ to SJ exercises.

Regional and muscle-specific adaptations in knee extensor hypertrophy using flywheel versus conventional weight-stack resistance exercise.

This study compared the effects of the most frequently employed protocols of flywheel (FW) versus weight-stack (WS) resistance exercise (RE) on regional and muscle-specific adaptations of the knee extensors. Sixteen men (n = 8) and women (n = 8) performed 8 weeks (2-3 days/week) of knee extension RE employing FW technology on 1 leg (4 × 7 repetitions), while the contralateral leg performed regular WS training (4 × 8-12 repetitions). Maximal strength (1-repetition maximum (1RM) in WS) and peak FW power were determined before and after training for both legs. Partial muscle volume of vastus lateralis (VL), vastus medialis (VM), vastus intermedius (VI), and rectus femoris (RF) were measured using magnetic resonance imaging. Additionally, quadriceps cross-sectional area was assessed at a proximal and a distal site. There were no differences (P > 0.05) between FW versus WS in muscle hypertrophy of the quadriceps femoris (8% vs. 9%), VL (10% vs. 11%), VM (6% vs. 8%), VI (5% vs. 5%), or RF (17% vs. 17%). Muscle hypertrophy tended (P = 0.09) to be greater at the distal compared with the proximal site, but there was no interaction with exercise method. Increases in 1RM and FW peak power were similar across legs, yet the increase in 1RM was greater in men (31%) than in women (20%). These findings suggest that FW and WS training induces comparable muscle-specific hypertrophy of the knee extensors. Given that these robust muscular adaptations were brought about with markedly fewer repetitions in the FW compared with WS, it seems FW training can be recommended as a particularly time-efficient exercise paradigm.

Metabolic equivalents of body weight resistance exercise with slow movement in older adults using indirect calorimetry.

We examined the metabolic equivalents (METs) of body weight resistance exercise with slow movement in older adults using indirect calorimetry. Thirteen men and 7 women (mean age, 70.8 ± 4.8 years) participating in this study performed 4 exercises (squat, knee push-up, crunch, and heel-raise). Squat was categorized as 3.6 to 3.8 METs, whereas knee push-up, crunch, and heel-raise were categorized as 2.1 to 3.2 METs based on aerobic energy expenditure. Those values are comparable with those of younger adults.

Assessing the usefulness of acute physiological responses following resistance exercise: sensitivity, magnitude of change, and time course of measures.

A variety of strategies exist to modulate the acute physiological responses following resistance exercise aimed at enhancing recovery and/or adaptation processes. To assess the true impact of these strategies, it is important to know the ability of different measures to detect meaningful change. We investigated the sensitivity of measures used to quantify acute physiological responses to resistance exercise and constructed a physiological profile to characterise the magnitude of change and the time course of these responses. Eight males accustomed to regular resistance exercise performed experimental sessions during a "control week", void of an exercise stimulus. The following week, termed the "exercise week", participants repeated this sequence of experimental sessions, and they also performed a bout of lower-limb resistance exercise following the baseline assessments. Assessments were conducted at baseline and at 2, 6, 24, 48, 72, and 96 h after the intervention. On the basis of the signal-to-noise ratio, the most sensitive measures were maximal voluntary isometric contraction, 20-m sprint, countermovement jump peak force, rate of force development (100-200 ms), muscle soreness, Daily Analysis Of Life Demands For Athletes part B, limb girth, matrix metalloproteinase-9, interleukin-6, creatine kinase, and high-sensitivity C-reactive protein with ratios >1.5. Clear changes in these measures following resistance exercise were determined via magnitude-based inferences. These findings highlight measures that can detect real changes in acute physiological responses following resistance exercise in trained individuals. Researchers investigating strategies to manipulate acute physiological responses for recovery and/or adaptation can use these measures, as well as the recommended sampling points, to be confident that their interventions are making a worthwhile impact.

Isometric parameters in the monitoring of maximal strength, power, and hypertrophic resistance-training.

This study monitored strength-training adaptations via isometric parameters throughout 2 × 10 weeks of hypertrophic (HYP I-II) or 10 weeks maximum strength (MS) followed by 10 weeks power (P) training with untrained controls. Trainees performed bilateral isometric leg press tests analyzed for peak force (maximal voluntary contraction (MVC)) and rate of force development (RFD) every 3.5 weeks. These parameters were compared with dynamic performance, voluntary and electrically induced isometric contractions, muscle activity, and cross-sectional area (CSA) in the laboratory before and after 10 and 20 weeks. RFD increased similarly during the first 7 weeks (HYP I, 44% ± 53%; MS, 48% ± 55%, P < 0.05), but RFD continued to increase up to 65% ± 61% from baseline (P < 0.01) only during P. These increases were concomitant with enhanced dynamic performances of 1-repetition maximum (1RM) (HYP I, 8% ± 6%; MS, 11% ± 6%, P < 0.001), and explosive repetitions during P (11% ± 15%, P < 0.05). Time to reach peak RFD differed (P < 0.001) between HYP (mean 42 ± 20 ms) and MS-P (mean 31 ± 12 ms) groups because of training. The changes in MVC correlated with the changes in CSA during weeks 1-20 (HYP I-II, r = 0.664; MS-P, r = 0.595, P ≤ 0.05), as well as changes in 1RM (r = 0.724, P < 0.05) during weeks 11-20 (HYP II). Muscle activity increased during MS and P only. Both MVC and RFD improvements reflected combinations of central and peripheral adaptations. RFD parameters may be effective tools to evaluate adaptations, particularly during maximal strength/power training, while MVC cannot distinguish between strength or muscle mass changes. Monitoring RFD provided important information regarding plateaus in RFD improvement, which were observed in dynamic explosive performances after HYP II compared with P.

Changes in HDL-c concentrations after 16 weeks of combined training in postmenopausal women: characteristics of positive and negative responders.

This study aimed to investigate the individual characteristics of body composition and metabolic profile that could explain interindividual variation in high-density lipoprotein cholesterol (HDL-c) concentrations in response to 16 weeks of combined strength plus aerobic (combined) training in postmenopausal women. The participants were divided into tertiles based on percentage of changes in HDL-c concentrations after combined training. Only women in the upper tertile (positive responders: Δ > 10.4%; n = 19) and lower tertile (negative responders: Δ < -1.4%; n = 19) were considered for analyses. The total body fat (BF), trunk fat (TF), android fat (AF), gynoid fat, and lean body mass were estimated by dual-energy X-ray absorptiometry. The metabolic profile - glucose, triacylglycerol, total cholesterol, HDL-c, low-density lipoprotein cholesterol, and very-low-density lipoprotein (VLDL) - were assessed. After 16 weeks, both positive and negative responders presented similar improvement in body composition, such as a decrease in percentage and kilograms of BF, TF, and AF, and increase in lean body mass (p value for time < 0.05). As expected, there was an effect of time and also a significant interaction (time vs. group) (p value < 0.001) in the improvement of HDL-c, with higher values for positive responders. Regarding metabolic profile, there were significant interactions (time vs. group) for triacylglycerol (p value = 0.032) and VLDL (p value = 0.027) concentrations, with lower values for positive responders. Our results suggests there is heterogeneity in combined training-induced HDL-c changes in postmenopausal women, and the positive responders were those who presented more pronounced decreases in triacylglycerol and VLDL concentrations.

Evidence of homologous and heterologous effects after unilateral leg training in youth.

The positive effects of unilateral training on contralateral muscles (cross education) has been demonstrated with adults for over a century. There is limited evidence for cross education of heterologous muscles. Cross education has not been demonstrated with children. It was the objective of this study to investigate cross-education training in children examining ipsilateral and contralateral homologous and heterologous muscles. Forty-eight male children (aged 10-13 years) were assessed for unilateral, ipsilateral and contralateral lower limb strength, power and endurance (1-repetition maximum (RM) leg press, knee extensors (KE) and flexors (KF) maximum voluntary isometric contractions (MVIC), countermovement jump, muscle endurance test (leg press repetitions with 60% 1RM)), and upper body unilateral MVIC elbow flexors (EF) and handgrip strength. An 8-week training program involved 2 unilateral leg press resistance-training groups (high load/low repetitions: 4-8 sets of 5RM, and low load/high repetitions: 1-2 sets of 20RM) and control (untrained) group. All muscles exhibited improvements of 6.1% to 89.1%. The trained limb exhibited greater adaptations than the untrained limb for leg press 1RM (40.3% vs. 25.2%; p = 0.005), and 60% 1RM leg press (104.1% vs. 73.4%; p = 0.0001). The high load/low repetition training induced (p < 0.0001) greater improvements than low load/high repetition with KE, KF, EF MVIC and leg press 1RM. This is the first study to demonstrate cross-education effects with children and that the effects of unilateral training involve both contralateral homologous and heterologous muscles with the greatest strength-training responses from high-load/low-repetition training.

The effect of resistance training set configuration on strength, power, and hormonal adaptation in female volleyball players.

The primary purpose of this investigation was to determine the impact of altering the set structure during an 8-week resistance training program on anthropometric, hormonal, and strength power characteristics. Thirty female volleyball players were recruited for participation and then randomly assigned to 1 of 3 resistance training groups: (i) cluster sets (CRT; n = 10), (ii) traditional sets (TRT; n = 10), or (iii) control (CON; n = 10). All athletes were evaluated for thigh and arm circumference, vertical jump, 20-m sprint, 4 × 9-m shuttle-run, 1-repetition maximum (1RM) back squat, bench press, military press, and deadlift prior to and after an 8-week periodized training intervention. Blood samples were taken before and after the 8-week training period to evaluate resting testosterone, cortisol, and insulin-like growth factor 1 responses to the training period. After 8 weeks of training the CRT group displayed a small but significant improvement in vertical jump (CRT: effect size (ES) = 038, 7.1%) performance when compared with the TRT group (ES = 0.34, 5.6%). Both the CRT and TRT training interventions resulted in very large increases in the 1RM squat (CRT: 8.4% ± 1.2%; TRT: 7.3% ± 0.6%), bench press (CRT: 8.3% ± 2.0%; TRT: 8.7% ± 1.9%), military press (CRT: 5.7% ± 1.2%; TRT: 5.5% ± 1.6%), and deadlift (CRT: 8.2% ± 1.6%; TRT: 8.3% ± 2.2%). There were no significant differences in 20-m sprint or 4 × 9-m shuttle run times between the CRT, TRT, and CON groups. These results suggest that cluster sets allow for greater improvements in vertical jump performance and equal improvements in strength gains to those seen with traditional sets.

Acute metabolic responses following different resistance exercise protocols.

Resistance exercise (RE) can be an excellent modality for glycemic control. Studies have demonstrated that a single RE session can reduce glycemia in subjects with or without diabetes. Little is known about the dose-response effect of RE on glycemic control. This study aimed to investigate the acute metabolic responses after different RE protocols. Eighty-nine males were separated into six groups that completed RE protocols: 2 sets of 18 repetitions (2 × 18 at 50% of 1-repetition maximum (1RM); n = 19); 3 sets of 12 repetitions (3 × 12 at 70% of 1RM; n = 14); 4 sets of 9 repetitions (4 × 9 at 80% of 1RM; n = 13); 6 sets of 6 repetitions (6 × 6 at 90% of 1RM; n = 19); circuit (2 × 18 at 50% of 1RM; n = 12); and a control session (n = 12). The exercise sequence consisted of 8 exercises. An oral glucose tolerance test was conducted with metabolic measurements immediately after each RE protocol and every 15 min until 120 min of recovery. All groups exhibited significantly lower values (p < 0.05) in the glucose area under the curve (AUC) when compared with control over a 120 min monitoring period. The 6 × 6 group showed a significantly lower glucose AUC versus the 3 × 12 and 4 × 9 groups (p = 0.004; p = 0.001, respectively). As for blood lactate, the control and 6 × 6 groups exhibited lower AUC values versus all other groups (p < 0.05), and AUC for glucose and lactate concentration showed a negative and significant correlation (r = -0.46; p < 0.0001). It appears that a combination of 9-12 repetitions per set and 3-4 sets per muscle group might be optimal for acute postprandial glucose control.

Using velocity loss for monitoring resistance training effort in a real-world setting.

The purpose of the present study was to evaluate the changes in movement velocity during resistance training with different loads while the trainees attempted to move the load at a predetermined repetition duration. Twenty-one resistance-trained men (age: 25.7 ± 5 years; height: 177.0 ± 7.2 cm; mass: 85.4 ± 13.56 kg) volunteered to participate in the study. Participants performed 2 test sessions. The first to determine 1-repetition maximum (1RM) load, and the second to evaluate velocity loss during a set to failure performed at 75% and 50% of 1RM using a 2-s concentric and 2-s eccentric repetition duration, controlled by a mobile app metronome. When using 75% 1RM there was a significant loss of movement velocity between the antepenultimate and the penultimate repetition (5.33%, p < 0.05), as well as during the penultimate and the last (22.11%, p < 0.05). At 50% of 1RM the participants performed the set until momentary failure without significant velocity loss. Monitoring velocity loss during high-load resistance training through simple methods can be an important tool for standardize the intensity of effort employed during submaximal training. This can be useful in clinical conditions where maximum exertions are contraindicated or when specific logistics are lacking.

Muscular performance and body composition changes following multi-joint versus combined multi- and single-joint exercises in aging adults.

The aim of the present study was to compare muscular performance and body composition changes following low-volume resistance-training programs consisting of multi-joint (MJ) exercises (cable chest press and seated row) versus a combination of multi- and single-joint (MJ+SJ) exercises (cable chest press, seated row, biceps curl, and triceps extension). Thirty untrained healthy aging adults were randomly assigned to 3 groups: MJ (n = 11), MJ+SJ (n = 11), and control (n = 8). Twelve-repetition maximums (12-RMs) for the cable chest press and seated row, localized muscular endurance for the elbow flexors handgrip strength, and body composition were assessed before and after the 8-week training program. All comparisons were analyzed via a mixed-model analysis with repeated measures (group × time) and the Bonferroni post hoc test (p < 0.05). The MJ and MJ+SJ groups increased performance in the 12-RM cable chest press (MJ = 61.5% ± 24.6% and MJ+SJ = 71.1% ± 25.6%), 12-RM seated row (MJ = 46.4% ± 26.3% and MJ+SJ = 51.5% ± 21.0%), localized muscular endurance (MJ = 24.7% ± 16.7% and MJ+SJ = 37.0% ± 11.4%), and handgrip strength (MJ = 9.3% ± 10.4% and MJ+SJ = 16.6% ± 25.3%) after the intervention. Body composition (i.e., trunk and upper limb fat and lean mass) did not change for any groups. No significant differences were observed between the MJ versus the MJ+SJ protocols after the intervention for any variables. In conclusion, for aging adults, either MJ or MJ+SJ low-volume resistance training resulted in similar increases in 12-RM, localized muscular endurance, and handgrip strength, without changes in body composition after 8 weeks of training.

The role of volume-load in strength and absolute endurance adaptations in adolescent's performing high- or low-load resistance training.

This study compared high- (HL) and low-load (LL) resistance training (RT) on strength, absolute endurance, volume-load, and their relationships in untrained adolescents. Thirty-three untrained adolescents of both sexes (males, n = 17; females, n = 16; 14 ± 1 years) were randomly assigned into either (i) HL (n = 17): performing 3 sets of 4-6 repetitions to momentary concentric failure; or (ii) LL (n = 16): performing 2 sets of 12-15 repetitions to momentary concentric failure. RT was performed for 2×/week for 9 weeks. Change in maximum strength (1 repetition maximum) and absolute muscular endurance for barbell bench press was assessed. Weekly volume-load was calculated as sets (n) × repetitions (n) × load (kg). Ninety-five percent confidence intervals (CIs) revealed that both groups significantly increased in strength and absolute endurance with large effect sizes (d = 1.51-1.66). There were no between-group differences for change in strength or absolute endurance. Ninety-five percent CIs revealed that both groups significantly increased in weekly volume-load with large effect sizes (HL = 1.66, LL = 1.02). There were no between-group differences for change in volume-load though average weekly volume-load was significantly greater for LL (p < 0.001). Significant Pearson's correlations were found for the HL group between average weekly volume-load and both strength (r = 0.650, p = 0.005) and absolute endurance (r = 0.552, p = 0.022) increases. Strength and absolute endurance increases do not differ between HL and LL conditions in adolescents when performed to momentary concentric failure. Under HL conditions greater weekly volume-load is associated with greater strength and absolute endurance increases.

Resistance exercise attenuates skeletal muscle oxidative stress, systemic pro-inflammatory state, and cachexia in Walker-256 tumor-bearing rats.

The aim of this study was to investigate the effects of resistance exercise training (RET) on oxidative stress, systemic inflammatory markers, and muscle wasting in Walker-256 tumor-bearing rats. Male (Wistar) rats were divided into 4 groups: sedentary controls (n = 9), tumor-bearing (n = 9), exercised (n = 9), and tumor-bearing exercised (n = 10). Exercised and tumor-bearing exercised rats were exposed to resistance exercise of climbing a ladder apparatus with weights tied to their tails for 6 weeks. The physical activity of control and tumor-bearing rats was confined to the space of the cage. After this period, tumor-bearing and tumor-bearing exercised animals were inoculated subcutaneously with Walker-256 tumor cells (11.0 × 107 cells in 0.5 mL of phosphate-buffered saline) while control and exercised rats were injected with vehicle. Following inoculation, rats maintained resistance exercise training (exercised and tumor-bearing exercised) or sedentary behavior (control and tumor-bearing) for 12 more days, after which they were euthanized. Results showed muscle wasting in the tumor-bearing group, with body weight loss, increased systemic leukocytes, and inflammatory interleukins as well as muscular oxidative stress and reduced mTOR signaling. In contrast, RET in the tumor-bearing exercised group was able to mitigate the reduced body weight and muscle wasting with the attenuation of muscle oxidative stress and systemic inflammatory markers. RET also prevented loss of muscle strength associated with tumor development. RET, however, did not prevent the muscle proteolysis signaling via FBXO32 gene messenger RNA expression in the tumor-bearing group. In conclusion, RET performed prior tumor implantation prevents cachexia development by attenuating tumor-induced systemic pro-inflammatory condition with muscle oxidative stress and muscle damage.

Detraining-induced alterations in adipokines and cardiometabolic risk factors after nonlinear periodized resistance and aerobic interval training in obese men.

This study compared the effects of nonlinear resistance training (NRT), aerobic interval training (AIT), and detraining on adipokines and cardiometabolic risk factors in middle-aged obese men. Thirty-three obese men were randomly allocated to NRT (n = 12), AIT (n = 10), and control (CON, n = 11) groups. Subjects in experimental groups performed exercise protocols 3 days per week for 12 weeks followed by a 4-week detraining period. The NRT involved 55 min of weight training with flexible periodization. The AIT consisted of running on a treadmill (4 × 4-min intervals at 90% of maximal heart rate, with each interval separated by 3 min at 65%). Peak oxygen consumption increased significantly after training compared with CON (P < 0.01), but it increased more in the AIT group than in the NRT group (P = 0.004). After detraining, peak oxygen consumption decreased significantly in both training groups (P < 0.001); however, the value in the AIT group was still higher than that in the CON group (P = 0.003). No significant changes were observed in serum levels of omentin-1 and interleukin (IL)-18 after training (P > 0.05), but omentin-1 decreased significantly in both training groups and IL-18 increased significantly in the NRT group after detraining (P < 0.05). High-density lipoprotein cholesterol (HDL-C) increased significantly after training in the AIT group compared with the CON group (P < 0.05) and returned to the pre-training level after detraining. Conversely, apelin-13 increased significantly in response to training, compared with baseline (P < 0.05), and remained unchanged after detraining. Both training regimens had similar effects on most markers; however, AIT seems to have stronger anti-coronary disease effects (as indicated by HDL-C and peak oxygen consumption) than NRT.

Volume-equated high- and low-repetition daily undulating programming strategies produce similar hypertrophy and strength adaptations.

The overarching aim of this study was to compare volume-equated high-repetition daily undulating periodization (DUPHR) versus a low-repetition daily undulating periodization (DUPLR) program for muscle performance. Sixteen college-aged (23 ± 3 years) resistance-trained males were counterbalanced into 2 groups: (i) DUPHR (n = 8), with a weekly training order of 12 repetitions (Day 1), 10 repetitions (Day 2), and 8 repetitions (Day 3); and (ii) DUPLR (n = 8), with a weekly training order of 6 repetitions (Day 1), 4 repetitions (Day 2), and 2 repetitions (Day 3). Both groups trained 3 times/week for 8 weeks on nonconsecutive days, with pre- and post-training testing during weeks 1 and 8. Participants performed only squat and bench press exercises each session. Changes in one-repetition maximum (1RM) strength, muscle thickness (MT), and muscular endurance (ME) were assessed. Both groups significantly increased 1RM strength for both squat and bench press (p < 0.01), and no group differences existed (p > 0.05). Similarly, both groups experienced significant increases in chest, lateral quadriceps distal, and anterior quadriceps MT (p < 0.05), but no change was present in either group for lateral quadriceps mid MT (p < 0.05). No group differences were discovered for changes in MT (p > 0.05). ME did not significantly change in the squat or bench press for either group (p > 0.05); however, for squat ME, a moderate effect size was observed for DUPHR (0.57) versus a trivial effect size for DUPLR (0.17). Our findings suggest that in previously trained males, training volume is a significant contributor to strength and hypertrophy adaptations, which occur independently of specific repetition ranges.

Plyometric exercise combined with high-intensity interval training improves metabolic abnormalities in young obese females more so than interval training alone.

The aim of this study was to compare the effects of 12 weeks of high-intensity interval training (HIIT) with the effects of 12 weeks of plyometric exercise combined with HIIT (P+HIIT) on anthropometric, biochemical, and physical fitness data in young obese females. Sixty-eight participants (age, 16.6 ± 1.3 y; body mass, 82.8 ± 5.0 kg; body fat, 39.4% ± 3.3%; body mass index z score, 2.9 ± 0.4) were assigned to 1 of 3 groups: HIIT (2 blocks per session of 6-8 bouts of 30-s runs at 100% velocity at peak oxygen uptake, with 30-s active recovery between bouts at 50%velocity at peak oxygen uptake (n = 23)); P+HIIT (2 blocks per session of 3 different 15-s plyometric exercises with 15-s passive recoveries, totaling 2 min for each plyometric exercise + the same HIIT program (n = 26)); or control (no exercise (n = 19)). Anthropometric (body mass, body mass index z score, body fat, lean body mass, and waist circumference), biochemical (plasma glucose, insulin, leptin and adiponectin concentrations, leptin/adiponectin ratio, and homeostasis model assessment of insulin resistance (HOMA-IR)), physical fitness (peak oxygen uptake, velocity at peak oxygen uptake, squat jump, and countermovement jump performances), and energy intake data were collected. Both training programs improved the anthropometric, biochemical, and physical fitness variables. However, the P+HIIT program induced greater improvements than did the HIIT program in lean body mass (+3.0% ± 1.7%), plasma glucose and leptin concentrations (-11.0% ± 4.7% and -23.8% ± 5.8%, respectively), plasma leptin/adiponectin ratio (-40.9% ± 10.9%), HOMA-IR (-37.3% ± 6.2%), and squat jump performance (22.2% ± 7.5%). Taken together, these findings suggest that adding plyometric exercises to a HIIT program may be more beneficial than HIIT alone in obese female adolescents.