Training-intensity Distribution on Middle- and Long-distance Runners: A Systematic Review.

Training-intensity distribution (TID) is considered the key factor to optimize performance in endurance sports. This systematic review aimed to: I) characterize the TID typically used by middle-and long-distance runners; II) compare the effect of different types of TID on endurance performance and its physiological determinants; III) determine the extent to which different TID quantification methods can calculate same TID outcomes from a given training program. The keywords and search strategy identified 20 articles in the research databases. These articles demonstrated differences in the quantification of the different training-intensity zones among quantification methods (i. e. session-rating of perceived exertion, heart rate, blood lactate, race pace, and running speed). The studies that used greater volumes of low-intensity training such as those characterized by pyramidal and polarized TID approaches, reported greater improvements in endurance performance than those which used a threshold TID. Thus, it seems that the combination of high-volume at low-intensity (≥ 70% of overall training volume) and low-volume at threshold and high-intensity interval training (≤ 30%) is necessary to optimize endurance training adaptations in middle-and long-distance runners. Moreover, monitoring training via multiple mechanisms that systematically encompasses objective and subjective TID quantification methods can help coaches/researches to make better decisions.

Effects of Manual Therapies and Resistance Exercise on Postexercise Hypotension in Women With Normal Blood Pressure.

ABSTRACT: Monteiro, ER, Pescatello, LS, Winchester, JB, Corrêa Neto, VG, Brown, AF, Budde, H, Marchetti, PH, Silva, JG, Vianna, JM, and Novaes, JdS. Effects of manual therapies and resistance exercise on postexercise hypotension in women with normal blood pressure. J Strength Cond Res 36(4): 948-954, 2022-The purpose of this investigation was to examine the acute effects of resistance exercise (RE) and different manual therapies (static stretching and manual massage [MM]) performed separately or combined on blood pressure (BP) responses during recovery in women with normal BP. Sixteen recreationally strength-trained women (age: 25.1 ± 2.9 years; height: 158.9 ± 4.1 cm; body mass: 59.5 ± 4.9 kg; body mass index: 23.5 ± 1.9 kg·m-2; baseline systolic BP median: 128 mm Hg; and baseline diastolic BP median: 78 mm Hg) were recruited. All subjects performed 6 experiments in a randomized order: (a) rest control (CON), (b) RE only (RE), (c) static-stretching exercise only (SS), (d) MM only, (e) RE immediately followed by SS (RE + SS), and (f) RE immediately followed by MM (RE + MM). RE consisted of 3 sets of bilateral bench press, back squat, front pull-down, and leg press exercises at 80% of 10RM. Static stretching and MM were applied unilaterally in 2 sets of 120 seconds to each of the quadriceps, hamstring, and calf regions. Systolic (SBP) and diastolic BP were measured before (rest) and every 10 minutes for 60 minutes following (Post 10-60) each intervention. There were significant intragroup differences for RE in Post-50 (p = 0.038; d = -2.24; ∆ = -4.0 mm Hg). Similarly, SBP intragroup differences were found for the SS protocol in Post-50 (p = 0.021; d = -2.67; ∆ = -5.0 mm Hg) and Post-60 (p = 0.008; d = -2.88; ∆ = -5.0 mm Hg). Still, SBP intragroup differences were found for the MM protocol in Post-50 (p = 0.011; d = -2.61; ∆ = -4.0 mm Hg) and Post-60 (p = 0.011; d = -2.74; ∆ = -4.0 mm Hg). Finally, a single SBP intragroup difference was found for the RE + SS protocol in Post-60 (p = 0.024; d = -3.12; ∆ = -5.0 mm Hg). Practitioners should be aware that SS and MM have the potential to influence BP responses in addition to RE or by themselves and therefore should be taken into consideration for persons who are hypertensive or hypotensive.

Effects of Different Types of Resistance Training and Detraining on Functional Capacity, Muscle Strength, and Power in Older Women: A Randomized Controlled Study.

ABSTRACT: Filho, MM, Venturini, GRdO, Moreira, OC, Leitão, L, Mira, PA, Castro, JB, Aidar, FJ, Novaes, JdS, Vianna, JM, and Caputo Ferreira, ME. Effects of different types of resistance training and detraining on functional capacity, muscle strength, and power in older women: A randomized controlled study. J Strength Cond Res 36(4): 984-990, 2022-Resistance training (RT) increases muscle strength, power, and functional capacity (FC) of older women. However, these benefits can be lost partially or totally with detraining. This study aimed to compare the effect of 20 weeks of different types of RT and 4 weeks of detraining on muscle strength, power, and FC in older women. Ninety-five older women were randomly divided into 4 experimental groups (strength endurance, power, absolute strength, and relative strength training) and 1 control group (CG). We assessed muscle strength (10RM test) and muscle power of the lower (countermovement jump) and upper limbs (medicine ball pitch). Functional capacity was assessed by the Senior Fitness Test, which comprises the following tests: 30-second arm curl, 30-second chair stand, back scratch, chair sit and reach, 8-foot up and go, and 6-minute walk. The experiment lasted 24 weeks (familiarization: 2 weeks; neural adaptation: 6 weeks; specific training: 12 weeks; and detraining: 4 weeks). Muscle strength, lower and upper limb power (all p < 0.05), 30-second arm curl, 30-second chair stand, 8-foot up and go, 6-minute walk (all p < 0.001), and lower limb flexibility (p = 0.002) improved in all experimental groups after training and CG showed no differences in any of these variables. After detraining, muscle strength, lower and upper limb power (p < 0.05 for all), and FC decreased in comparison to the end of RT (30-second arm curl, 30-second chair stand, 8-foot up and go, 6-minute walk, and lower limb flexibility, p < 0.05 for all). Although the FC of the subjects has been reduced after 4 weeks of detraining, it was maintained at higher levels in comparison to baseline. These results suggested that older women can be submitted to different types of RT to achieve improvements in general fitness.

Ischemic Preconditioning Improves Resistance Training Session Performance.

ABSTRACT: da Silva Novaes, J, da Silva Telles, LG, Monteiro, ER, da Silva Araujo, G, Vingren, JL, Silva Panza, P, Reis, VM, Laterza, MC, and Vianna, JM. Ischemic preconditioning improves resistance training session performance. J Strength Cond Res 35(11): 2993-2998, 2021-The aim of this study was to investigate the acute effect of ischemic preconditioning (IPC) in a resistance exercise (RE) training session on the number of repetitions performed, total volume, and rating of perceived exertion in recreationally trained and normotensive men. Sixteen recreationally trained and normotensive men completed 3 RE sessions in a counterbalanced and randomized order: (a) IPC protocol using 220 mm Hg followed by RE (IPC), (b) IPC cuff control protocol with 20 mm Hg followed by RE (CUFF), and (c) no IPC (control) followed by RE (CON). RE was performed with 3 sets of each exercise (bench press, leg press, lateral pulldown, hack machine squat, shoulder press, and Smith back squat) until concentric muscular failure, at 80% of one repetition maximum, with 90 seconds of rest between sets and 2 minutes of rest between exercises. Ischemic preconditioning and CUFF consisted of 4 cycles of 5 minutes of occlusion/low pressure alternating with 5 minutes of no occlusion (0 mm Hg) using a pneumatic tourniquet applied around the subaxillary region of the upper arm. For each condition, the number of repetitions completed, total volume of work performed, and rating of perceived exertion were determined. No significant difference was found for rating of perceived exertion between any experimental protocol. Ischemic preconditioning significantly (p < 0.05) increased the number of repetitions across exercises. Consequently, total volume performed (sum of total number of repetitions x load for each exercise) was significantly higher in IPC (46,170 kg) compared with CON (34,069 kg) and CUFF (36,590 kg) across all exercises. This work may have important implications for athletic populations because it demonstrates increase in muscle performance outcomes during a single RE session. Therefore, performing IPC before RE could be an important exercise prescription recommendation to increase maximum repetition performance and total volume of work performed and thus potentially increase desired training adaptations (i.e., strength and hypertrophy).

Effect of Resistance Training on Blood Pressure and Autonomic Responses in Treated Hypertensives.

Trevizani, GA, Seixas, MB, Benchimol-Barbosa, PR, Vianna, JM, da Silva, LP, and Nadal, J. Effect of resistance training on blood pressure and autonomic responses in treated hypertensives. J Strength Cond Res 32(5): 1462-1470, 2018-This study evaluated the effect of resistance training (RT) on heart rate variability (HRV) and on blood pressure (BP) responses to acute and short-term exposure in treated hypertensive (HT) subjects. Twenty-one men participated in the study, 8 HT under drug treatment regimen and achieving adequate BP control before inclusion and 13 normotensive (NT). The RT protocol consisted of 12 sessions with eight exercises (leg extension, leg press, leg curl, bench press, seated row, triceps push-down, seated calf flexion, and seated arm curl) performed for two sets of 15-20 repetitions with 50% of one repetition maximum with 2-minute rest intervals in between sets, 3×/week. Heartbeat measurements were taken before and after RT, and BP was measured at the beginning and at the end of each session after 10-minute rest. The repeated measures analysis of variance (effect: group vs. training) evaluated BP and HRV responses. Effect size (ES) calculation measured the magnitude of the RT effect on these variables. There was a statistically significant reduction in postexercise systolic BP in both groups (p = 0.040), without significant change in resting BP along RT (p = 0.159). Regarding HRV, it was observed a reduced sympathetic-vagal balance (training interaction vs. group: p = 0.058, ES = -0.83) in HT subjects. Resistance training promotes a significant acute reduction of BP in the HT and NT groups and provides a slight benefit of cardiac autonomic balance in the HT.

Do Men and Women Differ in Hematological Adaptations to 24 Weeks of Crossfit® Training?

Regular exercise can modulate the immune system functioning through changes in the number and function of leukocytes as well as in red blood cells and other typical blood markers. High intensity exercise promotes increases in cytotoxic activity, phagocytic capacity, chemotaxis and cell apoptosis. The aim of the study was to compare the chronic effects of a 24-week training program using CrossFit® methodology on hematological variables of men vs. women. Twenty-nine CrossFit® athletes (35.3 ± 10.4 years, 175.0 ± 9.2 cm, 79.5 ± 16.4 kg) participated in the study. The blood count, the lipid profile and glucose markers were measured every two months during the study period. The erythrocyte count and hemoglobin concentrations increased in months 4 and 6 in men and women, respectively. Hematocrit levels increased in men in months 2, 4 and 6, while in women only in month 6. Red cell distribution width increased in men in month 6 when compared to the value in month 2. Segmented neutrophils increased in men in month 6 and eosinophil levels increased in women in month 6. Differences between the two sexes were observed in monocytes levels at baseline, as well as in months 2, 4 and 6. Cross-Fit® training increased red cell count indicators in both sexes, which may be related to increased erythropoiesis. Some white blood cell counts were altered and these differed between sexes. The number of lymphocytes remained stable throughout the experiment.

The effect of complex contrast training with different training frequency on the physical performance of youth soccer players: a randomized study.

Background: Complex contrast training (CCT) is potentially an efficient method to improve physical abilities such as muscle strength, power output, speed, agility, are extremely important in developing soccer players of different age categories. Aim: This study aimed to analyze the effects of 6 weeks of CCT program applied in different training frequency (sessions per week) on youth soccer players performance. Methods: Twenty-one youth soccer players (age: 15.3 ± 1.1 years; body mass 64.9 ± 0.7 kg; height 175.4 ± 0.7 cm) were randomized into three groups: a regular pre-season training control group (G0, n = 8), a group with regular pre-season training plus twice-a-week CCT (G2, n = 6), and a group with regular pre-season training plus thrice-a-week CCT (G3, n = 7). The CCT consisted of soccer skills-based exercises distributed across five stations, to be performed before common regular practice during a 6-week pre-season period. The agility (505 Agility test), sprint (S5 and S15), jump (SJ and CMJ), and free kick speed (11 m from the goal) of the groups were analyzed pre- and post-CCT intervention. During a 6-week pre-season period, the players integrated CCT into their regular training sessions. Furthermore, performance variables were compared between the groups. Results: A statistical difference was identified for the timepoint for the players' CMJ (p = 0.023; η2 = 0.343) and the free kick speed (p = 0.013; η2 = 0.383) using ANOVA. The G3 showed a significant improvement in the CMJ (p = 0.001) and the free kick speed (p = 0.003) between pre- to post-CCT test. No other significant changes in performance were observed (p > 0.05). Conclusion: The CCT training program with a weekly frequency of 3 days per week is effective in improving free kick speed and CMJ performance in young male soccer players (U-15 and U-17 categories). CCT training programs have the potential to refine an athlete's preparation for competition. However, certain performance tests did not demonstrate substantial enhancements. Consequently, additional investigations are required to ascertain the effectiveness of CCT.

Reduction of leptin levels during acute exercise is dependent on fasting but not on caloric restriction during chronic exercise: A systematic review and meta-analysis.

BACKGROUND: The importance of leptin in controlling body mass has recently gained more attention. Its levels are directly associated with the amount of fat mass, but not necessarily dependent on it. Exercise has great potential in reducing leptin levels, however the response of exercise to this cytokine is still not well understood. OBJECTIVE: The objective of the review was to analyze the effects of physical exercise on plasma leptin concentration, either acutely (post-exercise/training session) and/or after a training period (short- or long-term), as well as to investigate the existence of possible moderating variables. METHODS: The studies included in this systematic review were published between 2005 and May 2023. Only peer-reviewed studies, available in English, performed with humans that evaluated the effects of any form of exercise on leptin levels were included. The search was conducted on May 03, 2023, in Embase (Elsevier), MEDLINE via PubMed®, and Web of Science (Core collection). The risk of bias in the included trials was assessed by the Physiotherapy Evidence Database tool, considering 11 questions regarding the methodology of each study with 10 questions being scored. The data (n, mean, and standard deviation) were extracted from included studies to perform random effects meta-analyses using standardized mean difference between the pre- and post-intervention effects. RESULTS: Twenty-five studies (acute effect: 262 subjects; short- and long-term effect: 377 subjects) were included in this systematic review and meta-analysis. Short- and long-term physical exercise and caloric restriction plus exercise reduce plasma leptin levels, presenting statistically significant differences (p<0.001); as well as acute effect (p = 0.035), however the latter result was influenced by the pre-exercise meal as shown in the subgroup analysis. In this meta-analysis the effect of moderating factors on leptin reduction, not addressed by past reviews, is verified, such as the relationship with caloric restriction, exercise intensity and pre-exercise meal on acute responses. CONCLUSION: Both acute and chronic exercise reduce leptin levels, yet the acute effect is dependent on the pre-exercise meal. In addition to having a long-term reduction in leptin levels, the minimum amount of weekly exercise to have a significant reduction in plasma leptin is 180 minutes of moderate-intensity exercise and 120 minutes of high-intensity exercise.

Manual myofascial release and muscle energy enhances trunk flexibility and strength in recreationally resistance-trained women: Cross-over study.

The purpose of this study was to compare the effects of myofascial release and muscle energy on acute outcomes in trunk extensors active range-of-motion and strength in recreationally resistance-trained women. Seventeen apparently healthy women performed three experimental protocols using a cross-over, randomized (counterbalanced in Latin Square format), and within-subjects design: a) range-of-motion and strength test after a manual myofascial release protocol (MFR); b) flexibility and strength test after a muscle energy protocol (ME); and c) range-of-motion and strength test without myofascial release or muscle energy (control condition). Active trunk range-of-motion was measured via a sit-and-reach test and trunk extension strength via isometric dorsal dynamometer. A significant increase in range-of-motion was found for MFR (p = 0.002; d = 0.71) and ME (p < 0.001; d = 0.47) when comparing post-intervention with baseline values. Similarly, a significant increase for strength was found for MFR (p = 0.018; d = 0.10) when comparing post-intervention with baseline values. In conclusion, both techniques (MFR and ME) improved trunk range-of-motion with the sit and reach test immediately post-intervention; however, MFR showed greater magnitude increases in range-of-motion (MFR: (medium magnitude) vs ME: small magnitude). Due to the potential health implications, both (MFR and ME) responses should be among the many considerations for rehabilitation and performance exercise prescription when prescribing an exercise regimen.

Effects of foam rolling and strength training on post exercise hypotension in normotensive women: A cross-over study.

Foam rolling (FR) has recently become very popular among athletes and recreational exercisers and is often used during warm up prior to strength training (ST) to induce self-myofascial release. The purpose was to examine the acute effects of ST and FR performed in isolation or in combination on blood pressure (BP) responses during recovery in normotensive women. Sixteen normotensive and strength trained women completed four interventions: 1) rest control (CON), 2) ST only, 3) FR only, and 4) ST immediately followed by FR (ST + FR). ST consisted of three sets of bench press, back squat, front pull-down, and leg press exercises at 80% of 10RM. FR was applied unilaterally in two sets of 120 s to each of the quadriceps, hamstring, and calf regions. Systolic (SBP) and diastolic (DBP) BP were measured before (rest) and every 10 min, for 60 min, following (Post 10-60) each intervention. Cohen's d effect sizes were calculated to indicate the magnitude effect by the formula d = Md/Sd, where Md is the mean difference and Sd is the standard deviation of differences. Cohen's d effect-sizes were defined as small (≥0.2), medium (≥0.5), and large (≥0.8). There were significant reductions in SBP for ST at Post-50 (p < 0.001; d = -2.14) and Post-60 (p < 0.001; d = -4.43), for FR at Post-60 (p = 0.020; d = -2.14), and for ST + FR at Post-50 (p = 0.001; d = -2.03) and Post-60 (p < 0.001; d = -2.38). No change in DBP was observed. The current findings suggest that ST and FR performed in isolation can acutely reduce SBP but without an additive effect. Thus, ST and FR can both be used to acutely reduce SBP and, importantly, FR can be added to a ST regimen without furthering the SBP reduction during recovery.

Cardiovascular and Perceptual Responses to Resistance Training with Practical Blood Flow Restriction Induced by a Non-Elastic Band vs. Pneumatic Cuff: A Crossover Randomized Study.

Our purpose in this study was to analyze perceptual and cardiovascular responses in low-load resistance training (RT) sessions associated with a fixed non-elastic band compressed to the proximal region of the arms (p-BFR) versus a pneumatic cuff inflated to a pressure of 150 mmHg (t-BFR). Participants (16 healthy trained men) were randomly assigned to two conditions of low-load RT (20% one repetition maximum [1RM]) with BFR (p-BFR or t-BFR). In both conditions, the participants performed five exercises (4 sets/30-15-15-15) for the upper-limbs, but in one of the conditions, the exercises were performed with a p-BFR induced by a non-elastic band, while in the other, the exercises were performed with a t-BFR using a device with similar width. The devices used to generate the BFR had similar widths (5 cm). Brachial blood pressure (bBP) and heart rate (HR) were measured before, after each exercise and after the experimental session (5-, 10-, 15-, and 20 min post-session). Rating of perceived exertion (RPE) and rating of pain perception (RPP) were reported after each exercise and 15 minutes post-session. HR increased during the training session in both conditions, with no differences between p-BFR and t-BFR. Neither intervention increased diastolic BP (DBP) during training, but there was a significant post-session reduction in DBP in the p-BFR, with no differences observed between conditions. There were no significant differences in RPE and RPP in the two training conditions, with both conditions associated with higher RPE and RPP at the end versus beginning of the experimental session. We conclude that when BFR device width and material are similar, low-load training with t-BFR and p-BFR promotes similar acute perceptual and cardiovascular responses in healthy trained men.

Chronic Effects of Different Intensities of Interval Training on Hemodynamic, Autonomic and Cardiorespiratory Variables of Physically Active Elderly People.

Interval training (IT) is a very efficient method. We aimed to verify the chronic effects of IT with different intensities on hemodynamic, autonomic and cardiorespiratory variables in the elderly. Twenty-four physically active elderly men participated in the study and were randomized into three groups: Training Group A (TGA, n = 8), Training Group B (TGB, n = 8) and control group (CG, n = 8). The TGA and TGB groups performed 32 sessions (48 h interval). TGA presented 4 min (55 to 60% of HRmax) and 1 min (70 to 75% of HRmax). The TGB training groups performed the same protocol, but performed 4 min at 45 to 50% HRmax and 1 min at 60 to 65% HRmax. Both training groups performed each set six times, totaling 30 min per session. Assessments were performed pre (baseline) after the 16th and 32nd intervention session. The CG performed only assessments. Hemodynamic, autonomic and cardiorespiratory (estimated VO2max) variables were evaluated. There were no significant differences between protocols and times (p > 0.05). However, the effect size and percentage delta indicated positive clinical outcomes, indicating favorable responses of IT. IT may be a strategy to improve hemodynamic, autonomic and cardiorespiratory behavior in healthy elderly people.

Acute Effect of Resistance Training With Blood Flow Restriction on Perceptual Responses: A Systematic Review and Meta-Analysis.

CONTEXT: Several studies have compared perceptual responses between resistance exercise with blood flow restriction and traditional resistance exercise (non-BFR). However, the results were contradictory. OBJECTIVES: To analyze the effect of RE+BFR versus non-BFR resistance exercise [low-load resistance exercise (LL-RE) or high-load resistance exercise (HL-RE)] on perceptual responses. DATA SOURCES: CINAHL, Cochrane Library, PubMed®, Scopus, SPORTDiscus, and Web of Science were searched through August 28, 2021, and again on August 25, 2022. STUDY SELECTION: Studies comparing the effect of RE+BFR versus non-BFR resistance exercise on rate of perceived exertion (RPE) and muscle pain/discomfort were considered. Meta-analyses were conducted using the random effects model. STUDY DESIGN: Systematic review and meta-analysis. LEVEL OF EVIDENCE: Level 2. DATA EXTRACTION: All data were reviewed and extracted independently by 2 reviewers. Disagreements were resolved by a third reviewer. RESULTS: Thirty studies were included in this review. In a fixed repetition scheme, the RPE [standardized mean difference (SMD) = 1.04; P < 0.01] and discomfort (SMD = 1.10; P < 0.01) were higher in RE+BFR than in non-BFR LL-RE, but similar in sets to voluntary failure. There were no significant differences in RPE in the comparisons between RE+BFR and non-BFR HL-RE; after sensitivity analyses, it was found that the RPE was higher in non-BFR HL-RE in a fixed repetition scheme. In sets to voluntary failure, discomfort was higher in RE+BFR versus non-BFR HL-RE (SMD = 0.95; P < 0. 01); however, in a fixed scheme, the results were similar. CONCLUSION: In sets to voluntary failure, RPE is similar between RE+BFR and non-BFR exercise. In fixed repetition schemes, RE+BFR seems to promote higher RPE than non-BFR LL-RE and less than HL-RE. In sets to failure, discomfort appears to be similar between LL-RE with and without BFR; however, RE+BFR appears to promote greater discomfort than HL-RE. In fixed repetition schemes, the discomfort appears to be no different between RE+BFR and HL-RE, but is lower in non-BFR LL-RE.

Joint and muscle injuries in men and women CrossFit® training participants.

OBJECTIVE: Verify the incidence and rate of joint and muscle injuries with the practice of CrossFit® and the potential risk factors for injuries in men and women. METHODS: A total of 184 CrossFit® participants (97 men and 87 women). A questionnaire was conducted based on characterization, training routine, injuries, and additional information. The incidence refers to the number of new cases of injury in the sample during the CrossFit® training. The injury rate was calculated by estimating the number of weekly training hours and converted into the number of injuries per 1000 training hours. RESULTS: Among the participants, 38.6% reported some type of injury, being joint injuries (83.1%) and/or muscle injuries (45.1%). The injury rate was 3.4/1000 h, with men having a higher rate. The location of the joint injuries was shoulders, wrists, and elbows, in addition to the lumbar spine in women. As for muscle injuries, the deltoid, upper back muscles, and quadriceps femoris were the most reported in men and deltoid, trapezius, upper back muscles, and gastrocnemius in women. CONCLUSIONS: A better understanding of the anatomical distribution of the injuries may help coaches prescribe the most adequate workout that may reduce the likelihood of injuries occurring in CrossFit® training participants. It was demonstrated that gender, experience, weekly frequency, and previous injuries are important factors, and professionals must be concerned with the assessment of the participants and with an individualized progression in order to avoid risks.

Ischemic Preconditioning Improves Handgrip Strength and Functional Capacity in Active Elderly Women.

BACKGROUND: Aging decreases some capacities in older adults, sarcopenia being one of the common processes that occur and that interfered with strength capacity. The present study aimed to verify the acute effect of IPC on isometric handgrip strength and functional capacity in active elderly women. METHODS: In a single-blind, placebo-controlled design, 16 active elderly women (68.1 ± 7.6 years) were randomly performed on three separate occasions a series of tests: (1) alone (control, CON); (2) after IPC (3 cycles of 5-min compression/5-min reperfusion at 15 mmHg above systolic blood pressure, IPC); and (3) after placebo compressions (SHAM). Testing included a handgrip isometric strength test (HIST) and three functional tests (FT): 30 s sit and stand up from a chair (30STS), get up and go time (TUG), and 6 min walk distance test (6MWT). RESULTS: HIST significantly increased in IPC (29.3 ± 6.9 kgf) compared to CON (27.3 ± 7.1 kgf; 7.1% difference; p = 0.01), but not in SHAM (27.7 ± 7.9; 5.5%; p = 0.16). The 30STS increased in IPC (20.1 ± 4.1 repetitions) compared to SHAM (18.5 ± 3.5 repetitions; 8.7%; p = 0.01) and CON (18.5 ± 3.9 repetitions; 8.6%; p = 0.01). TUG was significantly lower in IPC (5.70 ± 1.35 s) compared to SHAM (6.14 ± 1.37 s; -7.2%; p = 0.01), but not CON (5.91 ± 1.45 s; -3.7%; p = 0.24). The 6MWT significantly increased in IPC (611.5 ± 93.8 m) compared to CON (546.1 ± 80.5 m; 12%; p = 0.02), but not in SHAM (598.7 ± 67.6 m; 2.1%; p = 0.85). CONCLUSIONS: These data suggest that IPC can promote acute improvements in handgrip strength and functional capacity in active elderly women.

Ischemic Preconditioning with High and Low Pressure Enhances Maximum Strength and Modulates Heart Rate Variability.

Background: The application of ischemic preconditioning (IPC) to resistance exercise has attracted some attention, owing to increases in muscle performance. However, there is still no consensus on the optimal occlusion pressure for this procedure. This study compared the acute effects of IPC with high and low pressure of occlusion on upper and lower limb maximal strength and heart rate variability in recreationally trained individuals. Methods: Sixteen recreationally trained men (25.3 ± 1.7 years; 78.4 ± 6.2 kg; 176.9 ± 5.4 cm; 25.1 ± 1.5 m2 kg−1) were thoroughly familiarized with one repetition maximum (1 RM) testing in the following exercises: bench press (BP), front latissimus pull-down (FLPD), and shoulder press (SP) for upper limbs, and leg press 45º (LP45), hack machine (HM), and Smith Squat (SS) for lower limbs. The 1 RM exercises were then randomly performed on three separate days: after a high pressure (220 mmHg, IPChigh) and a low pressure (20 mmHg, IPClow) IPC protocol and after no intervention (control, CON). Heart rate variability was also measured at rest, during and after the entire IPC protocol, and after the exercises. Results: Maximal strength was significantly (p < 0.05) higher in both IPChigh and IPClow compared with CON in all upper- and lower-limb exercises. There was no difference between the two experimental conditions. No significant differences were found in the comparison across the different experimental conditions for LFnu, HFnu, LF/HF ratio, and RMSSDms. Conclusions: IPC performed with both high and low pressures influenced heart rate variability, which may partly explain the maximal strength enhancement.

Effects of Resistance Training to Muscle Failure on Acute Fatigue: A Systematic Review and Meta-Analysis.

BACKGROUND: Proper design of resistance training (RT) variables is a key factor to reach the maximum potential of neuromuscular adaptations. Among those variables, the use of RT performed to failure (RTF) may lead to a different magnitude of acute fatigue compared with RT not performed to failure (RTNF). The fatigue response could interfere with acute adaptive changes, in turn regulating long-term adaptations. Considering that the level of fatigue affects long-term adaptations, it is important to determine how fatigue is affected by RTF versus RTNF. OBJECTIVE: The aim of this systematic review and meta-analysis was to compare the effects of RTF versus RTNF on acute fatigue. METHODS: The search was conducted in January 2021 in seven databases. Only studies with a crossover design that investigated the acute biomechanical properties (vertical jump height, velocity of movement, power output, or isometric strength), metabolic response (lactate or ammonia concentration), muscle damage (creatine kinase activity), and rating of perceived exertion (RPE) were selected. The data (mean ± standard deviation and sample size) were extracted from the included studies and were either converted into the standardized mean difference (SMD) or maintained in the raw mean difference (RMD) when the studies reported the results in the same scale. Random-effects meta-analyses were performed. RESULTS: Twenty studies were included in the systematic review and 12 were included in the meta-analysis. The main meta-analyses indicated greater decrease of biomechanical properties for RTF compared with RTNF (SMD - 0.96, 95% confidence interval [CI] - 1.43 to - 0.49, p < 0.001). Furthermore, there was a larger increase in metabolic response (RMD 4.48 mmol·L-1, 95% CI 3.19-5.78, p < 0.001), muscle damage (SMD 0.76, 95% CI 0.31-1.21, p = 0.001), and RPE (SMD 1.93, 95% CI 0.87-3.00, p < 0.001) for RTF compared with RTNF. Further exploratory subgroup analyses showed that training status (p = 0.92), timepoint (p = 0.89), load (p = 0.10), and volume (p = 0.12) did not affect biomechanical properties; however, greater loss in the movement velocity test occurred on upper limbs compared with lower limbs (p < 0.001). Blood ammonia concentration was greater after RTF than RTNF (RMD 44.66 µmol·L-1, 95% CI 32.27-57.05, p < 0.001), as was 48 h post-exercise blood creatine kinase activity (SMD 0.86, 95% CI 0.33-1.42, p = 0.002). Furthermore, although there was considerable heterogeneity in the overall analysis (I2 = 83.72%; p < 0.01), a significant difference in RPE after RTF compared with RTNF was only found for studies that did not equalize training volumes. CONCLUSIONS: In summary, RTF compared with RTNF led to a greater decrease in biomechanical properties and a simultaneous increase in metabolic response, higher muscle damage, and RPE. The exploratory analyses suggested a greater impairment in the velocity of movement test for the upper limbs, more pronounced muscle damage 48 h post-exercise, and a greater RPE in studies with non-equalized volume after the RTF session compared with RTNF. Therefore, it can be concluded that RTF leads to greater acute fatigue compared with RTNF. The higher acute fatigue after RTF can also have an important impact on chronic adaptive processes following RT; however, the greater acute fatigue following RTF can extend the time needed for recovery, which should be considered when RTF is used. PROTOCOL REGISTRATION: The original protocol was prospectively registered (CRD42020192336) in the International Prospective Register of Systematic Reviews (PROSPERO).

Chronic Effects of Different Types of Neuromuscular Training on Hemodynamic Responses Estimated VO2max, and Walking Performance in Older People.

This paper investigated the effects over time of different forms of neuromuscular training on hemodynamic responses, the estimated VO2max, and walking performance. 105 older adults were randomly organized into three groups: RGA, RGB, and the Control Group (CG). RGA and RGB did 4 weeks of adaptation phase training and 12 weeks of intervention with different loads: moderate loads for RGB. and higher loads for RGA. A pre- and post-evaluation of the resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), double product (DP), estimated VO2max, and walking performance were assessed. Significant differences were observed for SBP, DBP, HR, and DP. For SBP, a post-evaluation reduction was observed only in RGA (p = 0.007) and when comparing RGA with the Control Group (p < 0.000). For the absolute VO2max, a significant improvement was seen in RGB compared to RGA (p = 0.037) and CG (p < 0.000). For the relative VO2max, RGB scored significantly higher than RGA (p < 0.000) and CG (p < 0.000), post-intervention. For the walk test, a significant reduction in completion times was observed for RGA (p = 0.027) and RGB (p < 0.000), and for RGB compared to RGA (p = 0.000) and CG (p < 0.000). Resistance training can be an excellent strategy for hemodynamic and cardiorespiratory improvement in the elderly.