Anterior cruciate ligament: A brief narrative review of main risk factors for injury and re-injury.

Anterior cruciate ligament (ACL) injury is one of the main injuries in professional and amateur athletes of different sports. Hundreds of thousands of ACL ruptures occurs annually, and only 55% of the athletes return to competitive level, with a 15 times higher chance of suffering a second injury. 60% of these injuries occur without physical contact and since they occur in the acute process, they can cause joint effusion, muscle weakness and functional incapacity. In the long term, they can contribute to a premature process of osteoarthritis. This narrative review is of particular interest for clinicians, practitioners, coaches and athletes to understand the main factors that contribute to an injury and/or re-injury and thus, to optimize their training to reduce and/or prevent the risk of injury and/or reinjury of ACL. Therefore, we aimed reports a narrative overview of the literature surrounding communication and explore through a theoretical review, the main risk factors for an ACL injury and/or re-injury, as well as bringing practical and correct methods of training applications. The lack of theoretical/practical knowledge on the part of rehabilitation and/or training professionals may impair the treatment of an athlete and/or student. High-quality research that can testing different training methods approaches in randomized controlled trials is needed.

Resistance Exercise Sessions Comprising Multijoint vs. Single-Joint Exercises Result in Similar Metabolic and Hormonal Responses, But Distinct Levels of Muscle Damage in Trained Men.

ABSTRACT: Barbosa, PH, Bueno de Camargo, JB, Jonas de Oliveira, J, Reis Barbosa, CG, Santos da Silva, A, Dos-Santos, JW, Verlengia, R, Barreira, J, Braz, TV, and Lopes, CR. Resistance exercise sessions comprising multijoint vs. single-joint exercises result in similar metabolic and hormonal responses, but distinct levels of muscle damage in trained men. J Strength Cond Res 38(5): 842-847, 2024-Resistance-type exercise (RE) elicits distinct acute metabolic and hormonal responses, which can be modulated by the manipulation of training variables. The purpose of this study was to compare the metabolic (blood lactate and estimated lactic anaerobic system energy expenditure) and hormonal (growth hormone [GH]) responses to RE sessions composed exclusively of multijoint (MULTI) or single-joint (SINGLE) exercises. Assessments of creatine kinase (CK) levels were also performed. In a crossover design, 10 recreationally resistance-trained men (age: 26.9 ± 3.0 years, total body mass: 83.2 ± 13.8 kg; height: 176 ± 7.0 cm; training experience: 5.5 ± 2.4 years) were randomly submitted to both protocols. Blood collections were made pre, 3 minutes after, and 36 hours after each experimental session. No significant difference between MULTI vs. SINGLE was observed for the rises in blood lactate (p = 0.057) and GH (p = 0.285) levels. For CK, a significant difference between the protocols was noted, in which MULTI resulted in significant rises after 3 minutes (p = 0.017) and 36 hours (p = 0.043) compared with SINGLE. In conclusion, the findings of this study suggest that resistance-trained individuals display similar metabolic and hormonal responses when performing MULTI and SINGLE exercise protocols. Also, RE sessions comprising MULTI exercises induce a higher magnitude of muscle damage, which may require a longer recovery period compared with SINGLE.

Muscle Hypertrophy Responses to Changes in Training Volume: A Retrospective Analysis.

This study assessed associations between changes in the weekly number of sets performed and the percentage change in muscle thickness of the biceps (MTBB) and triceps (MTTB) brachii muscles. Through a retrospective analysis, sixty-eight resistance-trained subjects that participated in previous studies had their previous training volumes analyzed and compared to the volume imposed during each individual study. The relationship between variables was determined through Spearman correlation and a k-cluster analysis was performed to subdivide the participants into three groups and classified as:<0%; 0-50%, and >50% increase in the number of sets for both muscle groups. Moderate and weak correlations were observed between the alterations in training volume and changes in MTBB (rs=0.44, p=0.001) and MTTB (rs=0.35, p=0.002), respectively. A significant difference was noted between<0% to >50% for MTBB and MTTB (p=0.017; p=0.042, respectively), while no significant difference was observed between<0% to 0-50% and 0-50% to >50% (both p >0.05) for both muscle groups. In conclusion, muscle hypertrophy of the upper limbs is only weakly to moderately associated with changes in training volume of trained subjects.

Does beta-alanine supplementation enhance adaptations to resistance training? A randomized, placebo-controlled, double-blind study.

The aim of the present study was to assess the effects of beta-alanine supplementation on muscle strength and thickness. Nineteen resistance-trained men (age: 27.3 ± 5.5 years; height: 178 ± 10 cm; body mass: 83.4 ± 9.7 kg; training experience: 5.9 ± 3.9 years) were allocated to one of the following groups: Beta-alanine (BA) (6.4 g/day of beta-alanine) or Placebo (PLA) (6.4 g/day of maltodextrin). Subjects completed 4 resistance training sessions per week for 8 weeks. The following assessments were performed before and after intervention periods: 1 repetition maximum (1RM) and 60%1RM tests in the bench press (60%1RMBENCH) and back squat (60%1RMSQUAT) exercises; muscle thickness assessment of biceps brachialis (MTBB), triceps brachialis (MTTB), and vastus lateralis (MTVL) by ultrasonography. No significant difference between groups was observed for the absolute increase (pre-post intervention) in the 1RMBENCH (mean difference = 0.8 kg; p = 0.679), 1RMSQUAT (mean difference = 0.1 kg; p = 0.992), MTBB (mean difference = 0.7 mm; p = 0.637), MTTB (mean difference = 1.4 mm; p = 0.282), MTVL (mean difference = 1.6 mm; p = 0.311), 60%1RMBENCH (mean difference = 0.5 repetitions; p = 0.670) and 60%1RMSQUAT (mean difference = 0.7 repetitions; p = 0.690). In conclusion, the 8-week training period induced significant strength and morphological responses. However, the addition of beta-alanine supplementation did not enhance these adaptive outcomes.

Acute Effect of the "Zero Point" Method on Muscle Thickness and Muscle Damage in Trained Men.

The "zero point" method allows for lower intensities for an exercise session without impairing the total training volume. This study aimed to compare the effects of the "zero point" versus the traditional method on muscle responses and muscle damage in trained men. Fifteen experienced men (age: 27.7 ± 6.4 years; body mass: 78.4 ± 11.4 kg; height: 174.8 ± 4.9 cm; experience: 5.86 ± 4.7 years; relative bench press strength: 1.38 ± 0.17 kg·kg-1) were subjected to two exercise protocols in a randomized order and separated by a week. The traditional and "zero point" methods were applied in the bench press, with loads of 70% and 50% of one repetition maximum (1RM), respectively, for 10 sets until concentric failure, with 3-min intervals between sets. The zero point method displayed a higher number of repetitions and time under tension than the traditional method, with no difference in the total training volume, echo intensity, algometry, lactate, and myoglobin. For the muscle thickness, no differences between the groups were presented, except for the deltoid muscle thickness, in which a higher post-training volume was observed compared to traditional training. The "zero point" method increases the demand on the deltoid muscles in the bench press exercise, but not on the pectoralis and triceps brachii.

Effects of resistance training on consecutive and non-consecutive days on hormonal, neuromuscular and morphological responses in recreationally trained men / Efeitos do treinamento de força em dias consecutivos e não consecutivos nas respostas hormonal, neuromuscular e morfológica em homens treinados recreacionalmente

abstract The purpose of the present study was to investigate the effect of two recovery periods between consecutive and non-consecutive days in strength training sessions on hormonal, neuromuscular and morphological variables in recreationally trained men. Nineteen young men completed the study and were randomly divided into two groups: 24R, 24-hour recovery group (n = nine) and 72R, 72-hour recovery group (n = ten). The strength training program (RT) lasted six weeks with two serial routines, with a weekly frequency of four times. The saliva sample was collected once a week in the morning to determine salivary testosterone. The 1RM, jump against movement and body composition tests were performed in the pre- and post-training periods. As for salivary testosterone, there was no significant effect with respect to time and between groups. Both groups improved maximal strength in terms of intervention time in the barbell bench press and in the leg press 45º, not differing between groups and body composition showed significant interaction in time to body fat percentage ∆% = -14.6 ± 10.0 (24R) and -17.2 ± 10.9 (72R); p = 0.00, fat mass ∆% = -13, 7 ± 9.2 (24R) and -18.2 ± 13.0 (72R); p = 0.00 and fat-free mass ∆% = 3.5 ± 2.7 (24R) and 2.5 ± 2 .8 (72R), p = 0.00. The recovery periods 24 and 72 hours between sessions induced similar responses in the parameters investigated in recreationally strength-trained men.

resumo O objetivo do presente estudo foi investigar o efeito de dois períodos de recuperação entre dias consecutivos e não consecutivos em sessões de treinamento de força sobre variáveis hormonais, neuromusculares e morfológicas em homens treinados recreacionalmente. Dezenove homens jovens completaram o estudo e foram divididos aleatoriamente em dois grupos: 24R, grupo de recuperação de 24 horas (n = nove) e 72R, grupo de recuperação de 72 horas (n = dez). O programa de treinamento de força (TF) durou seis semanas com duas rotinas seriadas, com frequência semanal de quatro vezes. A amostra de saliva foi coletada uma vez por semana no período da manhã para determinação da testosterona salivar. Os testes de 1RM, salto contra movimento e composição corporal foram realizados nos períodos pré e pós-treinamento. Quanto à testosterona salivar, não houve efeito significativo em relação ao tempo e entre os grupos. Ambos os grupos melhoraram a força máxima em termos de tempo de intervenção no supino reto com barra e no leg press 45º, não diferindo entre os grupos e composição corporal apresentaram interação significativa no tempo para percentual de gordura corporal ∆% = -14,6 ± 10,0 (24R) e -17,2 ± 10,9 (72R); p = 0,00, massa gorda ∆% = -13, 7 ± 9,2 (24R) e -18,2 ± 13,0 (72R); p = 0,00 e massa isenta de gordura ∆% = 3,5 ± 2,7 (24R) e 2,5 ± 2,8 (72R), p = 0,00. Os períodos de recuperação de 24 e 72 horas entre as sessões induziram respostas semelhantes nos parâmetros investigados em homens treinados de força recreacionalmente.

Manipulating Resistance Training Variables to Induce Muscle Strength and Hypertrophy: A Brief Narrative Review.

The regular practice of resistance training (RT) has been shown to induce relevant increases in both muscle strength and size. In order to maximize these adaptations, the proper manipulation of RT variables is warranted. In this sense, the aim of the present study was to review the available literature that has examined the application of the acute training variables and their influence on strength and morphological adaptations of healthy young adults. The information presented in this study may represent a relevant approach to proper training design. Therefore, strength and conditioning coaches may acquire a fundamental understanding of RT-variables and the relevance of their practical application within exercise prescription.

An Examination of Two Resistance Training Frequency Techniques in Morphological and Functional Adaptations of the Patellar Tendon.

The aim of the present study was to investigate the effects of distinct resistance training frequencies with equated-volume conditions in morphological and functional adaptations of the patellar tendon. Twenty-seven recreationally resistance-trained subjects (men [n=17] and women [n=10]) (age: 20.8 ± 1.9 years [range 18 to 25 years]; height: 1.73 ± 9.8 cm; total body mass = 73.2 ± 11.7 kg; previous RT experience = 3.3 ± 1.6 years) volunteered to participate in this study. A total of 16 training sessions were performed during the study period. Each subject's leg was randomly allocated to one of the following training protocols: 2 training sessions/week (2x) or 4 training sessions/week (4x). Measurements of tendon cross sectional area (CSA) and length were performed through ultrasound imaging. One repetition maximum test was performed to assess patellar tendon force (PTF) unilaterally. For CSA (2x: Δ= -1.3%; 4x: Δ= -0.9%), and length (2x: Δ= -0.4%; 4x: Δ= 1.2%), no significant differences were observed within or between conditions (all p > 0.05). For PTF, a significant difference was observed between conditions (mean difference = 0.05 [-125 to 224] p= 0.001). In conclusion, the leg extension exercise performed 2 vs 4x/week induces similar patellar tendon morphological responses. However, the increase in force seems to be enhanced by a lower weekly training frequency associated with a longer intervention period.

Tri-Set Training System Induces a High Muscle Swelling with Short Time Commitment in Resistance-Trained Subjects: A Cross-Over Study.

The purpose of the present study was to assess performance and morphological acute responses to the tri-set (TRI) resistance-training system. In a random order, 18 subjects (years: 30.0 ± 5.6; weight: 81.8 ± 13.4 kg; height: 173 ± 6.2 cm; RT experience: 4.6 ± 1.7 years) performed 3 exercises targeting the pectoralis major muscle in two different experimental conditions: traditional system (TRAD) and TRI. The TRAD protocol referred to the completion of a single exercise set followed by a rest period. For the TRI protocol, one set of each exercise was performed sequentially with a minimal rest interval afforded (< 10 seconds). Both protocols were performed in 3 sets of 10RM. Pectoralis major muscle swelling (PMMS), volume load (VL), internal training load (ITL) and training efficiency (TE) were calculated and compared between both protocols. Despite the low VL (-19.3%; p < 0.001), larger values of PMMS (104.7%; p < 0.001), ITL (24.3%; p < 0.001) and TE (56.0%; p < 0.001) were observed during TRI compared to TRAD condition. In conclusion, the adoption of a TRI training protocol may induce distinct performance and morphological acute responses compared to TRAD, suggesting that resistance-trained subjects may experience a higher muscle swelling and intensity of effort with short time commitment when performing TRI system.

Acute Effects of Inter-set Stretching on Performance and Metabolic Parameters of Resistance-trained Men.

The present study investigated acute muscular performance and metabolic responses to resistance training (RT) with inter-set stretching (ISS). Seventeen resistance-trained men (age: 30.0 ± 5.6 years; body mass: 81.8 ± 13.4 kg; height: 173 ± 6.2 cm; RT experience: 4.6 ± 1.7 years) completed the ISS and traditional training (TT) protocol seven days apart in a randomized order. In both protocols, 7 sets of the seated cable fly exercise were performed with a 10-repetition maximum (10-RM) load. During the ISS protocol, subjects completed inter-set passive static stretching of the agonist muscles for 45 seconds, while a passive rest (no stretching) was adopted for the same duration in the TT protocol. The change in maximal bench press strength (1-RM), muscle swelling (ultrasound) of the pectoralis major (PMMS), and blood lactate were assessed immediately following each protocol. Additionally, the total load lifted (TLL) and internal training load (ITL) were assessed in both protocols. There was no difference between protocols for the change in maximal bench press 1-RM (p > 0.05). There were higher values for PMMS (p < 0.05) and blood lactate (p < 0.05) following the TT versus the ISS protocol. The TT resulted in higher TLL (p < 0.05) and ITL values (p < 0.05) versus the ISS protocol. Resistance training with inter-set stretching results in lower acute performance and metabolic responses versus traditional training with passive rest between sets. Therefore, inter-set stretching might be applied within a periodized program on lower intensity days to reduce the overall stress of a session.

Dissociated Time Course of Indirect Markers of Muscle Damage Recovery Between Single-Joint and Multi-joint Exercises in Resistance-Trained Men.

ABSTRACT: de Camargo, JBB, Braz, TV, Batista, DR, Germano, MD, Brigatto, FA, and Lopes, CR. Dissociated time course of indirect markers of muscle damage recovery between single-joint and multi-joint exercises in resistance-trained men. J Strength Cond Res 36(8): 2089-2093, 2022-This study compared the time course of indirect markers of muscle damage after multi-joint and single-joint exercises. Ten resistance-trained men (years: 26.9 ± 3.0; total body mass: 83.2 ± 13.8 kg; height: 176 ± 7.0 cm; resistance training [RT] experience: 5.5 ± 2.4 years; RT frequency: 5.3 ± 0.7 sessions; relative squat 1 repetition maximum: 1.4 ± 0.3) performed, in a random order, 5 sets of 8 repetition maximum of the back squat (BS) and knee extension (KE) exercises. Rectus femoris muscle thickness (MT RF ), leg circumference (LC), and muscle soreness (MS) were recorded at baseline (pre), 0, 12, 24, and 36 hours after each exercise protocol. There was a significant increase ( p < 0.05) in dependent variables at every time point after both the multi-joint and single-joint exercise sessions. However, MT RF and LC were greater at 0 and 36 hours, and MS was greater at 24 and 36 hours after BS when compared with KE (all p < 0.05). This study shows that resistance-trained individuals can experience significant higher levels of indirect markers of muscle damage when performing a multi-joint lower-limb exercise compared with a single one.

Twice-daily sessions result in a greater muscle strength and a similar muscle hypertrophy compared to once-daily session in resistance-trained men.

BACKGROUND: The present study investigated the mid-term effects of training muscle groups once- versus twice-daily on morphofunctional adaptations in trained men. METHODS: Participants were randomly assigned to 1 of 2 experimental groups: 1 daily session per muscle group (1S, N.=11), where every muscle group was trained once a day or 2 daily sessions per muscle group (2S, N.=12), where every muscle group was trained twice. Testing was conducted before intervention and after 8 weeks for maximal strength (1RM) and muscular endurance (60%1RM) for bench press and parallel back squat exercises, and muscle thickness (MT) of the biceps brachii, triceps brachii, vastus lateralis, anterior quadriceps and pectoralis major. RESULTS: The major findings were as follows: 1) the increase in 1RM back squat was significantly greater in 2S (∆=16.1%) compared to 1S (∆=7.8%) (P<0.05); 2) both groups significantly increased bench press 1RM (1S: ∆=4.6%; 2S: ∆=6.8%), back squat 60% 1RM (1S: ∆=19.0%; 2S: ∆=24.3%), bench press 60% 1RM (1S: ∆=15.4%; 2S: ∆=24.0%) and all MT outcomes (P<0.05 for all), with no differences between experimental groups (1S and 2S). CONCLUSIONS: This study provides evidence that a twice-daily resistance training augments lower-body muscular strength; however, the daily frequency does not seem to have any additive effect on upper-body muscular strength, muscular endurance, and muscle hypertrophy in trained men.

High Resistance-Training Volume Enhances Muscle Thickness in Resistance-Trained Men.

ABSTRACT: Brigatto, FA, Lima, LEdM, Germano, MD, Aoki, MS, Braz, TV, and Lopes, CR. High resistance-training volume enhances muscle thickness in resistance-trained men. J Strength Cond Res 36(1): 22-30, 2022-This study investigated the effects of different volumes of resistance training (RT) (8 weeks of 16, 24, and 32 weekly sets per muscle group) on muscular strength and hypertrophy. Subjects were pair-matched according to baseline strength and then randomly assigned to 1 of 3 experimental groups: 16 weekly sets per muscle group (G16, n = 9), 24 weekly sets per muscle group (G24, n = 9), or 32 weekly sets per muscle group (G32, n = 9). All other RT variables (e.g., exercise performed, exercise order, weekly frequency, range of repetitions, rest interval between sets and exercises, etc.) were maintained constant. The total load lifted was calculated for every RT session to compare the accumulated external training load among experimental groups across the intervention period. Testing was conducted before intervention (pre) and after 8-week (post-8) periods for maximal voluntary muscle strength (1 repetition maximum [1RM] test for bench press and parallel back squat exercises) and muscle thickness (MT) of the biceps brachii, triceps brachii, and vastus lateralis. The major findings were as follows: (a) all RT volumes increased bench press and parallel back squat 1RM and (b) all RT volumes increased the biceps brachii, triceps brachii, and vastus lateralis MT. The magnitude of increase in 1RM and MT of the lower body when training with 32 weekly sets per muscle group was higher than for 16 weekly sets per muscle group. The magnitude of the increase in MTTB was higher when training with 32 weekly sets than for 16 weekly sets.

Effect of Different Recoveries During HIIT Sessions on Metabolic and Cardiorespiratory Responses and Sprint Performance in Healthy Men.

ABSTRACT: Germano, MD, Sindorf, MAG, Crisp, AH, Braz, TV, Brigatto, FA, Nunes, AG, Verlengia, R, Moreno, MA, Aoki, MS, and Lopes, CR. Effect of different recoveries during HIIT sessions on metabolic and cardiorespiratory responses and sprint performance in healthy men. J Strength Cond Res 36(1): 121-129, 2022-The purpose of this study was to investigate how the type (passive and active) and duration (short and long) recovery between maximum sprints affect blood lactate concentration, O2 consumed, the time spent at high percentages of V̇o2max, and performance. Subjects were randomly assigned to 4 experimental sessions of high-intensity interval training exercise. Each session was performed with a type and duration of the recovery (short passive recovery-2 minutes, long passive recovery [LPR-8 minutes], short active recovery-2 minutes, and long active recovery [LAR-8 minutes]). There were no significant differences in blood lactate concentration between any of the recoveries during the exercise period (p > 0.05). The LAR presented a significantly lower blood lactate value during the postexercise period compared with LPR (p < 0.01). The LPR showed a higher O2 volume consumed in detriment to the active protocols (p < 0.001). There were no significant differences in time spent at all percentages of V̇o2max between any of the recovery protocols (p > 0.05). The passive recoveries showed a significantly higher effort time compared with the active recoveries (p < 0.001). Different recovery does not affect blood lactate concentration during exercise. All the recoveries permitted reaching and time spent at high percentages of V̇o2max. Therefore, all the recoveries may be efficient to generate disturbances in the cardiorespiratory system.

Resistance-Trained Individuals Can Underestimate the Intensity of the Resistance Training Session: An Analysis Among Sexes, Training Experience, and Exercises.

ABSTRACT: Dos Santos, WM, Tavares Junior, AC, Braz, TV, Lopes, CR, Brigatto, FA, and Dos Santos, JW. Resistance-trained individuals can underestimate the intensity of the resistance training session: An analysis among genders, training experience, and exercises. J Strength Cond Res 36(6): 1506-1510, 2022-Resistance training (RT) promotes improvements in healthy parameters for young to elderly adults and athletes' performance. Strength and muscle mass improvements are dependent on exercise intensity. This study verifies whether 53 healthy young adults underestimate exercise intensity in 3 different exercises, such as bench press (BP), biceps curl (BC), and leg press 45° (LP). Researchers asked the subjects "How much load do you use to perform 10 repetitions in this exercise usually in workout routines?" in each exercise. Individuals warmed up and then performed as many repetitions as possible until they reached the concentric failure. Deviations from data normality were found by using Levene's test; the number of repetitions per exercise within sex was tested by using Friedman's test and Conover's post hoc and Kruskal-Wallis tests to compare the number of repetitions between sex and RT experience. We correlated the number of repetitions and training experience using the Spearman test. The number of repetitions for both groups (male and female) is greater than 8-12 repetitions for BC and LP and BP of the female group, except for men who perform around 8-12 repetitions on BP. Frequency of maximal repetitions reached for 8-12 repetitions for women was 12% for BP, 28% for BC, and 28% for LP. The frequency men reached was 46.5% for BP, 14.3% for BC, and 14.3% for LP. Training experience did not influence the number of repetitions reached. Resistance training practitioners underestimate exercise load (56% of total sample) to be independent of experience. Women underestimate exercise load more than men. Based on the present results, it is possible to state that RT should not be prescribed considering a predefined number of repetitions and a linked percentage of loads, without the guidance for frequent adjustments of loads, according to the exercise performed.

Beta-alanine Supplementation for Four Weeks Increases Volume Index and Reduces Perceived Effort of Resistance-trained Men: A Pilot Study.

The aim of the present study was to assess the short-term effects of four weeks of beta-alanine supplementation (BA) (6.4 g/day) on the total volume performed and perceived effort of resistance-trained individuals. Sixteen trained men (age: 27.3 ± 5.0 years, height: 1.78 ± 0.1 cm, total body mass: 84.3 ± 8.4 kg, RT experience: 5.9 ± 3.3 years) were allocated in one of the following groups: BA or Placebo (PLA). In addition, during the same period, participants were submitted to a resistance training program. Volume index (VI) and the rate of perceived exertion (RPE) were collected during the experimental period for both groups. Significant increases from the first to the last intervention week in VI were observed only for BA (+6.5%, d = 0.61, p = 0.04). In addition, supplementation induced a lower mean RPE (BA: 8.8 ± 0.5 AU vs. PLA: 9.4 ± 0.3 AU, p = 0.02). In conclusion, four weeks of BA supplementation were able to increase resistance-training volume without affecting the perceived effort of trained men.

Acute Effect of Different Duration of Foam Rolling Protocols on Muscle Thickness, Pain Pressure Threshold, and Volume Load on Multiple Sets of Knee Extension.

Previous studies investigated the effects of foam rolling (FR) on measurements of strength and power. However, the acute effect of FR on muscle thickness (MT) and pressure pain threshold (PPT) after multiple sets of resistance exercise remains to be elucidated. The aim of the present study was to examine the effect of one and three minutes of quadriceps FR on muscle thickness (vastus lateralis [VL] and rectus femoris [RF]), pain threshold (VL and RF), and total load lifted (TLL) on multiple sets of knee extension. Nine resistance-trained men (age: 24.8 ± 5.2 years; height: 177 ± 7 cm; total body mass 77.7 ± 6.2 kg) participated the study. MT, PPT, and performance on multiple sets of knee extension were compared after performing passive recovery (CON), one minute (FR1), or three minutes of FR (FR3). A similar total training load among experimental conditions was observed. There was a greater increase on VL muscle thickness after FR3 when compared to CON and FR1. In addition, there was an increase on rectus femoris PPT two minutes post FR3, with no differences between conditions. These results indicate that longer duration FR-protocol may acutely increase muscle thickness of the vastus lateralis muscle without negatively affect the TLL and PTT.

Order of Resistance Training Cycles to Develop Strength and Muscle Thickness in Resistance-Trained Men: A Pilot Study.

The aim of the present study was to assess the chronic effects of different order of resistance training cycles on strength and muscle thickness of recreationally resistance-trained men. The study sample was composed of 16 healthy men (age: 25.0 ± 3.8 years, height: 1.77 ± 7.6 cm, total body mass: 81.7 ± 10.4 kg, RT experience: 4.6 ± 0.7 years, relative bench press one repetition maximum: 1.2 ± 0.1, relative squat one-repetition maximum: 1.5 ± 0.2). According to baseline maximal strength, participants were allocated in one of the following groups: Maximal Strength-Strength Endurance (MS-SE) (six weeks of a maximal strength cycle followed by six weeks of a strength endurance cycle); Strength Endurance -Maximal Strength (MS-SE) (six weeks of a strength endurance cycle followed by six weeks of a maximal strength cycle). The following measurements were performed in the pre and post intervention periods: one-repetition maximum (1RM) on parallel back squat and bench press exercises, muscle thickness evaluation of biceps brachialis (MTBB), triceps brachialis (MTTB), and vastus lateralis (MTVL) by ultrasonography. Total load lifted (TLL) and Internal training load (ITL) were also assessed. Both groups presented significant increases in bench press (MS-SE p = 0.001, SE-MS p = 0.003) and half squat (MS-SE p = 0.004, SE-MS p = 0.001) 1RM, MTBB (MS-SE p = 0.020, SE-MS p = 0.005) and MTTB (MS-SE p = 0.001, SE-MS p = 0.001). For MTVL, a significant increase was observed only for MS-SE group (MS-SE p = 0.032, SE-MS p = 0.143). No significant difference between groups was observed for any strength or morphological outcomes. In conclusion, both MS-SE and SE-MS training cycles are effective strategies to enhance resistance training adaptations in trained men.

Acute Effects of Foam Rolling on Cycling Performance: A Randomized Cross-Over Study.

Acute foam rolling protocols may increase range of motion without a negative impact on muscle performance. The main purpose of the present study was to investigate the acute effects of foam rolling on cycling performance (mean power and maximal power), affect and perceived exertion. A secondary aim was to assess the effect of foam rolling on post-exercise muscle soreness. In a random order, ten recreationally trained cyclists (age: 26 ± 5 years; height 1.76 ± 0.06 m; total body mass 78.3 ± 19.8 kg; cycling experience: 5.6 ± 5.3 years; 4.1 ± 1.3 cycling sessions per week and 1.4 ± 1.4 strength sessions per week) were submitted to the following experimental conditions (separated by one week) before performing a three-minute, all-out cycling test: foam rolling or control. During foam rolling protocol, participants were instructed to roll back and forth on one leg and to place the opposite leg crossed over, from the proximal to the distal portion of the rectus femoris and vastus lateralis during one set of sixty seconds for each muscle group. Feeling scale (10 min pre and post-test), CR-10 scale of perceived exertion (ten-minute post-test), pressure pain threshold (pre and 24 h post-test) and mean/maximal power were assessed. No significant differences were observed between conditions for mean and maximal power, affect, perceived exertion, and pressure pain threshold (all p > 0.05). In conclusion, a pre-exercise acute session of self-myofascial release does not improve performance and post-exercise muscle soreness of recreationally trained cyclists.

Chronic Effects of Heavy Load Activity Performed Before Resistance Training Sessions on the Physical Performance of Youth Soccer Players.

The adoption of resistance training (RT) programs has been shown to positively influence sports performance-related parameters. However, the chronic effects of maximal strength protocols on the performance of soccer players are not completely investigated. The aim of this study was to evaluate the effects of performing two repetition maximum (2RM) before a resistance training session on the physical performance of youth soccer players. Seventeen players (under-20 category) were allocated in one of the following groups: 2RM + resistance training group (2RM + RT, n = 8) and resistance training group (RTG, n = 9). Both groups performed the same RT protocol during experimental weeks. However, the 2RM + RT performed 1 set of 2RM for 4 exercises, previously to RT protocol. Pre and post intervention period, one repetition maximum of the back squat exercise (1RMSQUAT), sprint time (15m-sprint test), countermovement jump (CMJ), repeated sprint ability (RSABEST and RSAMEAN), and yo-yo intermittent recovery test level-2 (YYIRT2) were assessed. Total load lifted (TLL) during the experimental weeks was also collected. Significant increases in 1RMSQUAT (2RM + RT: +45.1%, d = 4.40; RTG: +32.3%, d = 1.84), 15m sprint (2RM + RT: -9.0%, d = 7.9; RTG: -8.8%%, d = 3.2), CMJ (2RM + RT: +2.3%, d = 0.17; RTG: +0.8%, d = 0.07), RSABEST (2RM + RT: -2.4%, d = 0.6; RTG: -2.3%, d = 1.04), RSAMEAN (2RM + RT: -2.9%, d = 1.33; RTG: -3.4%, d = 1.78), YYIRT2 (2RM + RT: +12.0%, d = 0.82; RTG: +12.1%, d = 0.63) (all p < 0,05) were observed for both groups on pre to post-intervention periods, with no significant difference between groups. Therefore, the 2RM + RT protocol did not promote additional increase on performance of young soccer players.