Effects of Six-week Periodized Versus Non-Periodized Kettlebell Swing Training on Strength, Power and Muscular Endurance.

The purpose of this study was to compare a periodized versus a non-periodized protocol of kettlebell (KTB) swings over six weeks on strength, power, and muscular endurance. Twenty-eight high intensity functional training (HIFT) practitioners were assigned to non-periodized (NPG = 11), periodized (PG = 11), or control groups (CG = 6). NPG used the same load (20 kg) throughout the training period while the PG used a step loading progression (with an added four kilograms every two weeks). Measures of strength and muscular endurance in the deadlift exercise, and power in the countermovement jump were assessed before and after six weeks. A two-way ANOVA was used to verify pre- to post-test differences in strength, power, and muscular endurance. An analysis of the effect size was also incorporated. For strength and power, statistical differences from pre- to post-test were found for both the NPG (p < 0.001; 1-RM improvement = 8.7%; jump height improvement = 8.7%) and PG (p < 0.001; 1-RM improvement = 7.8%; jump height improvement = 10.1%), with no difference between groups. For muscular endurance, only the PG showed significant differences from pre- to post-test (p = 0.013; muscular endurance improvement = 23.8%). In conclusion, when the goal is to increase strength and power performances in HIFT practitioners, periodized and non-periodized KTB models appear to be equally effective, and this can simplify the strength coach's practice in programming KTB swing training periods. For muscular endurance, the addition of KTB swing on a periodized basis seems to be a more effective strategy.

Interaction effects of different orders of resistance exercises and rest intervals on performances by young athletes.

OBJECTIVE: The purpose of this study was to verify the acute effects of different exercise orders and rest intervals between sets on young athletes performance. METHOD: Sixteen young male football players (73.2 ± 4.8 kg, 177.5 ± 5.1 cm, BMI 23.2 ± 1.1, 19.8 ± 0.9 years) completed six experimental strength training (ST) sessions with different exercise order sequences (A and B) and rest interval lengths (1 min, 3 min, and self-selected).In Sequence A the exercises were: bench press (BP), back squat (BS), biceps curl (BC) and plantar flexion (PF); while Sequence B was performed in the opposite order (i.e. PF, BC, BS and BP).The total work volume (TWV) per exercise (sets x repetitions x load) and per training session (sum of the TWV of all exercises) were evaluated for all ST sessions. RESULTS: BC and PF exercises presented higher TWV in sequence B (p ≤ 0.05). Already, the exercises BP, BS and PF presented higher TWV with 3 min and self-selected rest intervals (p ≤ 0.05). The 3-min and self-selected rest intervals presented higher values of TWV per training session compared to the 1-min rest interval (p ≤ 0.05). CONCLUSION: The exercise order influenced certain exercises (BC and PF), which presented higher TWV when positioned at the beginning of a sequence. While the longer rest intervals (3 min and self-selected) resulted in higher TWV per exercise (BP, BS and PF) and per training session. These results suggest that self-selected rest interval can be implemented to increase training efficiency in young athletes.

The Effect of Exercise Order in Circuit Training on Muscular Strength and Functional Fitness in Older Women.

The purpose of this study was to analyze the effect of different orders of exercises in circuit training on strength and functional fitness in older women over a 12-week period. After 10 repetition maximum (10-RM) and functional fitness baseline testing, thirty older women were randomly assigned into two groups. The exercise order for Group 1 was leg press, wide-grip lat pulldown, knee extension, pec deck fly, plantar flexion and triceps extension; Group 2 performed the same exercises, but in the opposite order: triceps extension, plantar flexion, pec deck fly, knee extension, wide-grip lat pulldown and leg press. Both groups performed the circuit three times with a load that permitted 8 to 10 repetitions per exercise set. Both groups exhibited gains in 10-RM strength and functional fitness test performance (p ≤ 0.05). In Comparing groups, the G1 presented greater strength gains for the wide-grip lat pulldown, while G2 showed higher values for the plantar flexion and triceps extension exercises (p ≤ 0.05). Both circuit exercise orders were effective and could be applied to promote strength and functional fitness gains. However, based on the results for the wide-grip lat pulldown, plantar flexion and triceps extension, it seems that exercise order should be considered when specific muscle weaknesses are a priority, so that these muscles are trained first within a circuit.

Influência da frequência semanal do treinamento de força sobre o desempenho funcional em idosas / Influence of the weekly frequency of strength training on functional performance in older women

Introdução: No envelhecimento ocorrem declínios estruturais e funcionais que podem afetar a independência física. O treinamento de força (TF) é capaz de promover melhoras neste quesito, entretanto, poucos experimentos investigaram a influencia da frequência semanal. Objetivo: verificar a influência da frequência semanal do TF sobre o desempenho funcional em idosas. Métodos: 21 mulheres idosas foram divididas em dois grupos que treinavam em uma (G1: n=11) ou duas vezes por semana (G2: n=10). O TF aplicado foi no formato de circuito que consistiu de três passagens com intervalo de 30 segundos entre os exercícios e faixa de repetições entre oito a 10. Resultados: Os resultados demonstraram melhora em relação ao pré-treinamento em todos os testes em ambos os grupos (p<0,05). No entanto, não foram observadas diferenças significativas entre os grupos (p>0,05). Conclusão: O TF é capaz de promover melhoras no desempenho funcional independe da frequência de treinamento.

Introducion: Aging occur declines structural and functional that can to affect physical independence. Objective: Verify the influence of weekly frequency of Strength Training (ST) on functional performance in older women. Methods: 21 older women were divided in two groups that trained in one (G1: n=11) or two times a week (G2: n=10). The ST applied was in format of circuit that consisted of three turns with interval of 30 seconds in between exercises and repetitions between eight and 10. Results: Results showed improvement over pre-training in all tests in both groups (p <0.05). However, no significant differences were observed between groups (p> 0.05). Conclusion: ST is capable of promoting improvements in functional performance regardless of training frequency.

Volume for Muscle Hypertrophy and Health Outcomes: The Most Effective Variable in Resistance Training.

Resistance training is the most effective method to increase muscle mass. It has also been shown to promote many health benefits. Although it is deemed safe and of clinical relevance for treating and preventing a vast number of diseases, a time-efficient and minimal dose of exercise has been the focus of a great number of research studies. Similarly, an inverted U-shaped relationship between training dose/volume and physiological response has been hypothesized to exist. However, the majority of available evidence supports a clear dose-response relationship between resistance training volume and physiological responses, such as muscle hypertrophy and health outcomes. Additionally, there is a paucity of data to support the inverted U-shaped response. Although it may indeed exist, it appears to be much more plastic than previously thought. The overarching principle argued herein is that volume is the most easily modifiable variable that has the most evidenced-based response with important repercussions, be these muscle hypertrophy or health-related outcomes.

Extreme Conditioning Program Induced Acute Hypotensive Effects are Independent of the Exercise Session Intensity.

The aim of the study was to determine the acute systolic (SBP) and diastolic (DBP) blood pressure, rating of perceived exertion (RPE) and heart rate (HR) responses following two intense training sessions (24 hours apart). Nine male extreme conditioning program (ECP) practitioners with more than 6 months of experience (age 26.7 ± 6.6 years; body mass 78.8 ± 13.2 kg; body fat 13.5 ± 6.2 %) completed two experimental ECP sessions. Cardiovascular variables were measured before, immediately after and every 15 min during a 45 min recovery following each experimental session. Compared with pre-exercise data, our results showed a SBP decrease at 30 min post exercise session 1 (P≤0.05) and at 45 min following exercise session 2. DBP decreased (P≤0.05) at 15 min and 30 min following exercise session 1 and at 30 min after the exercise session 2, respectively. HR remained significantly higher (P≤0.05) 45 min following the first and second exercise session compared with pre-exercise values. Exercise session 1 induced a higher increase in HR (86 ± 11% of HRmax versus 82 ± 12% of HRmax, p = 0.01) and RPE (8.8 ± 1.2 versus 8.0 ± 1.2, p = 0.02) when compared to exercise session 2. In conclusion, post-exercise hypotension occurs following strenuous exercise sessions, regardless of the session design, which may have an important role in the prevention of cardiovascular diseases.

Effects of fixed vs. self-suggested rest between sets in upper and lower body exercises performance.

In its last position stand about strength training, the American College of Sports Medicine recommends a rest interval (RI) between sets ranging between 1 and 3 min, varying in accordance with the objective. However, there is no consensus regarding the optimal recovery between sets, and most studies have investigated fixed intervals. Therefore, the aim of this study was to analyse the effects of fixed versus self-suggested RI between sets in lower and upper body exercises performance. Twenty-seven healthy subjects (26 ± 1.5; 75 ± 15 kg; 175 ± 12 cm) were randomly assigned into two groups: G1: lower body exercises and G2: upper body exercises. Squat and leg press 1 repetition maximum (1RM) were tested for the G1 and bench press and biceps curl 1RM for G2. After the 1RM tests, both groups performed three sets to concentric failure with 75% of 1RM in combination with different RIs (2 min or self-suggested) on separate days and the exercises performance was evaluated by the number of repetitions. The results demonstrated no significant differences in the number of repetitions between 2 min and self-suggested RIs that presented similar reductions with the sets progression. It was also shown that the self-suggested RI spent less time recovering than the 2 min RI group on average. This suggests that for individuals with previous experience, the self-suggested RI can be an effective option when using workloads commonly prescribed aiming hypertrophy. Also, the self-suggested RI can reduce the total training session duration, which can be a more time-effective strategy.

Influence of inter-set stretching on strength, flexibility and hormonal adaptations.

Adequate levels of strength and flexibility are important for the promotion and maintenance of health and functional autonomy as well as safe and effective sports participation. The aim of the present study was to analyze the effects of 8 weeks of strength training with or without inter-set static stretching on strength, flexibility and hormonal adaptations of trained men. Sixteen trained men were randomly divided into 2 groups: the static stretching group (SSG) and passive interval group (PIG). All participants performed 24 training sessions 3 times a week. The test and retest of 8RM, strength, flexibility, cortisol and growth hormone concentration in pre and post test conditions were also evaluated. To compare the differences between and within groups in pre- and post-training tests, ANOVA with repeated measures was performed (SSGpre x SSGpost; PIGpre x PIGpost; SSGpost x PIGpost). An alpha level of p<0.05 was considered statistically significant for all comparisons. Both groups showed significant increases in strength (SSGpre vs. SSGpost; PIGpre vs. PIGpost) in the same exercises for leg extension (LE) and Low Row (LR). Specifically, in the SSG group, the parameters for LE were (p = 0.0015 and ES = 2.28 - Large), and the parameters for LR were (p = 0.002 and ES = 1.95 - Large). Moreover, in the PIG group, the parameters for LE were (p = 0.009 and ES = 1.95 - Large), and the parameters for LR were (p = 0.0001 and ES = 2.88 - Large). No differences were found between the groups (SSGpost vs. PIGpost). Both groups showed significant increases in flexibility but in different joints (SSGpre vs. SSGpost; PIGpre vs. PIGpost). In the SSG group, only three joints showed significant increases in flexibility: shoulder extension (p = 0.004 and ES = 1.76 - Large), torso flexion (p = 0.002 and ES = 2.36 - Large), and hip flexion (p = 0.001 and ES = 1.79 -Large). In the PIG group, only three joints showed increases in flexibility: horizontal shoulder abduction (p = 0.003 and ES = 2.07 - Large), hip flexion (p = 0.001 and ES = 2.39 - Large), and hip extension (p = 0.02 and ES = 1.79 - Large). In-between group analyses (SSGpost x PIGpost) revealed differences in two joints: shoulder extension (p = 0.001) and horizontal shoulder abduction (p = 0.001). Hormonal profiles showed no significant differences in cortisol secretion or growth hormone concentration. In conclusion, both studied strength protocols (with and without inter-set static stretching) resulted in flexibility and strength gains without an effect on the anabolic and catabolic hormonal profile.

Influence of upper-body exercise order on hormonal responses in trained men.

The aim of this study was to examine acute hormonal responses after different sequences of an upper-body resistance-exercise session. Twenty men completed 2 sessions (3 sets; 70% 1-repetition maximum; 2 min passive rest between sets) of the same exercises in opposite sequences (larger to smaller vs. smaller to larger muscle-group exercises). Total testosterone (TT), free testosterone (FT), testosterone/cortisol (T/C) ratio, sex-hormone-binding globulin (SHBG), growth hormone (GH), and cortisol (C) concentrations were measured before and immediately after each sequence. The results indicate that the GH concentration increased after both sessions, but the increase was significantly greater (p < 0.05) after the sequence in which larger muscle-group exercises were performed prior to the smaller muscle-group exercises. No differences were observed between sessions for TT, FT, SHBG, C, or the T/C ratio at baseline or immediately after resistance exercise. These results indicate that performing larger muscle-group exercises first in an upper-body resistance-exercise session leads to a significantly greater GH response. This may have been due to the significantly greater exercise volume accomplished. In summary, the findings of this investigation support the common prescriptive recommendation to perform larger-muscle group exercises first during a resistance-exercise session.

Comparison between nonlinear and linear periodized resistance training: hypertrophic and strength effects.

The aim of this study was to investigate the effects of nonlinear periodized (NLP) and linear periodized (LP) resistance training (RT) on muscle thickness (MT) and strength, measured by an ultrasound technique and 1 repetition maximum (1RM), respectively. Thirty untrained men were randomly assigned to 3 groups: NLP (n = 11, age: 30.2 ± 1.1 years, height: 173.6 ± 7.2 cm, weight: 79.5 ± 13.1 kg), LP (n = 10, age: 29.8 ± 1.9 years, height: 172.0 ± 6.8 cm, weight: 79.9 ± 10.6 kg), and control group (CG; n = 9, age: 25.9 ± 3.6 years, height: 171.2 ± 6.3 cm, weight: 73.9 ± 9.9 kg). The right biceps and triceps MT and 1RM strength for the exercises bench press (BP), lat-pull down, triceps extension, and biceps curl (BC) were assessed before and after 12 weeks of training. The NLP program varied training biweekly during weeks 1-6 and on a daily basis during weeks 7-12. The LP program followed a pattern of intensity and volume changes every 4 weeks. The CG did not engage in any RT. Posttraining, both trained groups presented significant 1RM strength gains in all exercises (with the exception of the BP in LP). The 1RM of the NLP group was significantly higher than LP for BP and BC posttraining. There were no significant differences in biceps and triceps MT between baseline and posttraining for any group; however, posttraining, there were significant differences in biceps and triceps MT between NLP and the CG. The effect sizes were higher in NLP for the majority of observed variables. In conclusion, both LP and NLP are effective, but NLP may lead to greater gains in 1RM and MT over a 12-week training period.

Exercise order in resistance training.

Resistance training (RT) is now an integral component of a well rounded exercise programme. For a correct training prescription, it is of the utmost importance to understand the interaction among training variables, such as the load, volume, rest interval between sets and exercises, frequency of sessions, exercise modality, repetition velocity and, finally, exercise order. Sports medicine research has indicated that exercise order is an important variable that affects both acute responses and chronic adaptations to RT programmes. Therefore, the purpose of this review was to analyse and discuss exercise order with relevance to acute responses (e.g. repetition performance) and also the expression of chronic adaptable characteristics (e.g. maximal strength and hypertrophy). To accomplish this purpose, the Scielo, Science Citation Index, National Library of Medicine, MEDLINE, Scopus, SPORTDiscus™ and CINAHL® databases were accessed to locate previously conducted original scientific investigations. The studies reviewed examined both acute responses and chronic adaptations with exercise order as the experimental variable. Generally, with relevance to acute responses, a key finding was that exercise order affects repetition performance over multiple sets, indicating that the total repetitions, and thus the volume, is greater when an exercise is placed at the beginning of an RT session, regardless of the relative amount of muscle mass involved. The pre-exhaustion method might not be an effective technique to increase the extent of neuromuscular recruitment for larger muscle groups (e.g. pectoralis major for the bench press) when preceded by a single-joint movement (e.g. pec-deck fly). With relevance to localized muscular endurance performance, oxygen consumption and ratings of perceived exertion, the limited amount of research conducted thus far indicates that exercise order does not appear to impact the acute expression of these variables. In terms of chronic adaptations, greater strength increases were evident by untrained subjects for the first exercise of a given sequence, while strength increases were inhibited for the last exercise of a given sequence. Additionally, based on strength and hypertrophy (i.e. muscle thickness and volume) effect-size data, the research suggests that exercises be ordered based on priority of importance as dictated by the training goal of a programme, irrespective of whether the exercise involves a relatively large or small muscle group. In summary, exercise order is an important variable that should receive greater attention in RT prescription. When prescribed appropriately with other key prescriptive variables (i.e. load, volume, rest interval between sets and exercises), the exercise order can influence the efficiency, safety and ultimate effectiveness of an RT programme.

Strength training's chronic effects on muscle architecture parameters of different arm sites.

Strength training generates alterations in muscle geometry, which can be monitored by imaging techniques as, for example, the ultrasound (US) technique. There is no consensus about the homogeneity of hypertrophy in different muscle sites. Therefore, the purpose of this study was to compare the muscle thickness (MT) and pennation angle (PA) in 3 different sites (50, 60, and 70% of arm length) of the biceps brachii and triceps brachii after 12 weeks of strength training. Forty-nine healthy untrained men were divided into 2 groups: Training Group ([TG, n = 40] 29.90 ± 1.72 years; 79.53 ± 11.84 kg; 173 ± 0.6 cm) and Control Group (n = 9 25.89 ± 3.59 years; 73.96 ± 9.86 kg; 171 ± 6 cm). The TG underwent a strength training program during 12 weeks, which included exercises such as a free-weight bench press, machine lat pull-down, triceps extension in lat pull-down, and standing free-weight biceps curl with a straight bar. A US apparatus was used to measure the PA and MT at the 3 sites. The maximal voluntary isometric contraction (MVC) test was conducted for each muscle group. After 12 weeks of training, a significant difference was observed between MT in biceps brachii, with an improvement of 12% in the proximal site, whereas the distal site increased by only 4.7% (p < 0.05). For the long head of the triceps brachii, the MT and PA at the 3 sites presented significant increases, but no significant variation was observed among them, probably because of the pennated-fiber arrangement. The MVC increased significantly for both muscle groups. The results indicated that the strength training program was efficient in promoting hypertrophy in both muscles, but with dissimilar responses of the pennated and fusiform muscle architecture at different arm sites.

Effects of linear vs. daily undulatory periodized resistance training on maximal and submaximal strength gains.

The objective of this study was to verify the effect of 2 periodized resistance training (RT) methods on the evolution of 1-repetition maximum (1RM) and 8RM loads. Twenty resistance trained men were randomly assigned to 2 training groups: linear periodization (LP) group and daily undulating periodization (DUP) group. The subjects were tested at baseline and after 12 weeks for 1RM and 8RM loads in leg press (LEG) and bench press (BP) exercises. The training program was performed in alternated sessions for upper (session A: chest, shoulder and triceps) and lower body (session B: leg, back and biceps). The 12-week periodized training was applied only in the tested exercises, and in the other exercises, 3 sets of 6-8RM were performed. Both groups exhibited significant increases in 1RM loads on LEG and BP, but no statistically significant difference between groups was observed. The same occurred in 8RM loads on LEG and BP. However, DUP group presented superior effect size (ES) in 1RM and 8RM loads for LEG and BP exercises when compared to the LP group. In conclusion, periodized RT can be an efficient method for increasing the strength and muscular endurance in trained individuals. Although there was no statistically significant difference between periodization models, DUP promoted superior ES gains in muscular maximal and submaximal strength.

Influence of rest interval lengths on hypotensive response after strength training sessions performed by older men.

The purpose of this study was to compare the postexercise hypotensive response after different rest intervals between sets (1 and 2 minutes) in normotense older men. Seventeen older men (67.6 ± 2.2 years) with at least 1 year of strength training experience participated. After determination of 10 repetition maximum (10RM) loads for exercises, subjects performed 2 different strength training sessions. On the first day, volunteers performed 3 sets of 10 repetitions per exercise at 70% 10RM, with 1 or 2 minutes' rest interval between sets depending on random assignment. On the second day, the procedures were similar but with the other rest interval. There was no difference in systolic and diastolic blood pressure between rest intervals at any time point measure. Before 1- and 2-minute sessions, the systolic blood pressure values were 122.7 ± 6.0 and 123.2 ± 3.7 mm Hg, and diastolic blood pressure values were 80.5 ± 5.6 and 82.0 ± 3.7 mm Hg, respectively. Both 1 and 2 minute sessions still presented reduced values for systolic blood pressure after 60 minutes (102.9 ± 6.9 and 106.7 ± 5.4 mm Hg, respectively), while the diastolic blood pressure presented significant reductions for 50 minutes after a 1 minute session (12.1 to 5.6 mm Hg) and for 60 minutes after the 2 minute session (13.3 to 6.5 mm Hg). Additionally, the systolic and diastolic blood pressure effect size data demonstrated higher magnitudes at all time point measures after the 2-minute rest sessions. These results suggest a poststrength training hypotensive response for both training sessions in normotense older men, with higher magnitudes for the 2-minute rest session. Our findings suggest a potentially positive health benefit of strength training.

Influence of moderately intense strength training on flexibility in sedentary young women.

The present study is the first to examine whether moderately intense resistance training improves flexibility in an exclusively young, sedentary women population. Twenty-four, young, sedentary women were divided into 3 groups as follows: agonist/antagonist (AA) training group, alternated strength training (AST) group, or a control group (CG). Training occurred every other day for 8 weeks for a total of 24 sessions. Training groups performed 3 sets of 10 to 12 repetitions per set except for abdominal training where 3 sets of 15 to 20 reps were performed. Strength (1 repetition maximum bench press) and flexibility were assessed before and after the training period. Flexibility was assessed on 6 articular movements: shoulder flexion and extension, horizontal shoulder adduction and abduction, and trunk flexion and extension. Both groups increased strength and flexibility significantly from baseline and significantly when compared with the CG (p ≤ 0.05). The AST group increased strength and flexibility significantly more than the AA group (p ≤ 0.05) in all but one measurement. This study shows that resistance training can improve flexibility in young sedentary women in 8 weeks.

Influence of exercise order on maximum strength and muscle volume in nonlinear periodized resistance training.

The purpose of this study was to examine the influence of exercise order on strength and muscle volume (MV) after 12 weeks of nonlinear periodized resistance training. The participants were randomly assigned into 3 groups. One group began performing large muscle group exercises and progressed to small muscle group exercises (LG-SM), whereas another group started with small muscle group exercises and advanced to large muscle group exercises (SM-LG). The exercise order for LG-SM was bench press (BP), machine lat pull-down (LPD), triceps extension (TE), and biceps curl (BC). The order for the SM-LG was BC, TE, LPD, and BP. The third group did not exercise and served as a control group (CG). Training frequency was 2 sessions per week with at least 72 hours of rest between sessions. Muscle volume was assessed at baseline and after 6 weeks and 12 weeks of training by ultrasound techniques. One repetition maximum strength for all exercises was assessed at baseline and after 12 weeks of training. Effect size data demonstrated that differences in strength and MV were exhibited based on exercise order. Both training groups demonstrated greater strength improvements than the CG, but only BP strength increased to a greater magnitude in the LG-SM group as compared with the SM-LG. In all other strength measures (LPD, TE, and BC), the SM-LG group showed significantly greater strength increases. Triceps MV increased in the SM-LG group; however, biceps MV did not differ significantly between the training groups. In conclusion, if an exercise is important for the training goals of a program, then it should be placed at the beginning of the training session, regardless of whether or not it is a large muscle group exercise or a small muscle group exercise.

Exercise order interacts with rest interval during upper-body resistance exercise.

The purpose of this study was to compare repetition performance when resting 1 minute vs. 3 minutes between sets and exercises for an upper-body workout performed in 2 different sequences. Sixteen recreationally trained men completed 4 experimental resistance exercise sessions. All sessions consisted of 3 sets with an 8-repetition maximum load for 6 upper-body exercises. Two different exercise sequences (i.e., A or B) were performed with either 1- or 3-minute rest between sets and exercises, respectively. For sequence A1 (SEQA1) and sequence A3 (SEQA3), resistance exercises were performed in the following order: lat pull-down with a wide grip (LPD-WG), lat pull-down with a close grip (LPD-CG), machine seated row (SR-M), barbell row lying on a bench (BR-B), dumbbell seated arm curl (SAC-DB), and machine seated arm curl (SAC-M). Conversely, for sequence B1 (SEQB1) and sequence B3 (SEQB3), the exercises were performed in the opposite order. The results demonstrated that the effect of exercise order was stronger than the effect of rest interval length for LPD-WG (SEQA3>SEQA1>SEQB3>SEQB1) and SAC-M (SEQB3>SEQB1>SEQA3>SEQA1), whereas the effect of rest interval length was stronger than the effect of exercise order for LPD-CG, SR-M, SAC-DB (SEQA3=SEQB3>SEQA1=SEQB1), and BR-B (SEQB3>SEQA3=SEQB1>SEQA1). These results suggest that upper-body exercises involving similar muscle groups and neural recruitment patterns are negatively affected in terms of repetition performance when performed at the end vs. the beginning of a session, and the reduction in repetition performance is greater when using 1-minute vs. 3-minute rest interval between sets.

Creatine kinase and lactate dehydrogenase responses after upper-body resistance exercise with different rest intervals.

The purpose of the current study was to compare serum creatine kinase (CK) and lactate dehydrogenase (LDH) concentrations at multiple time points after resistance exercise sessions that incorporated different rest intervals between sets and exercises. Twenty untrained men (18.65+/-0.49 years, 68.30+/-7.98 kg, and 174.4+/-4.80 cm) performed 2 resistance exercise sessions (i.e., 3 sets with 80% 1 repetition maximum for 5 upper-body exercises) with either 1-minute (SEQ1) or 3-minute (SEQ3) rest between sets and exercises. For each session, CK and LDH concentrations were measured before exercise (PRE) and 24, 48, and 72 hours after exercise (24P, 48P, and 72P). Subjects lifted a 24% greater (p<0.05) volume load during SEQ3 than during SEQ1. Within SEQ1, significant differences in CK concentrations were demonstrated between most time points, except between 24P and 72P. Similarly, within SEQ3, significant differences in CK concentrations were demonstrated between most time points, except between 24P and 72P and between 48P and 72P. The CK concentrations were highest at 48P for both sessions. When the CK concentrations were compared between SEQ1 and SEQ3, no significant differences were demonstrated at any time point. Within SEQ1, a significant difference in LDH concentration was demonstrated between 48P and 72P. Within SEQ3, significant differences in LDH concentrations were demonstrated between PRE and 24P and between PRE and 48P. The LDH concentrations were highest at 72P for SEQ1 and at 24P for SEQ3. When the LDH concentrations were compared between SEQ1 and SEQ3, no significant differences were demonstrated at any time point. These results suggest that muscle damage was similar between rest intervals; however, the volume load completed to induce the muscle damage was significantly greater when 3-minute rest intervals were employed. Therefore, when considered relative to the volume load completed, 1-minute rest intervals during resistance exercise may invoke greater muscle damage.

Acute cardiovascular response in anabolic androgenic steroid users performing maximal treadmill exercise testing.

The purpose of this study was to investigate the cardiovascular effects of anabolic androgenic steroid (AAS) use, specifically the hemodynamic response, during maximal treadmill exercise testing by comparing the exercise response between users of AAS (U-AAS) and non-AAS users (N-AAS). Twenty-four men (n=12; 29+/-3.4 years and n=12; 29.5+/-8.2 years for the U-AAS and N-AAS groups, respectively) with regular participation in both resistance (mean=6 d.wk) and aerobic exercise (mean=2 d.wk) volunteered for the study. Both groups of subjects completed a ramp-protocol maximal treadmill exercise test to volitional fatigue. Several hemodynamic and metabolic measures were obtained before, during, and after testing. The results demonstrate for the first time that chronic administration of high doses of AAS (355.4+/-59.47 mg.wk) lead to hemodynamic and metabolic response impairment. In conclusion, the chronotropic significant incompetence in the current study was reflected by an exaggerated hemodynamic response to exercise. Furthermore, the findings suggest that nonusers of AAS showed increases in VO2max when compared to the AAS group. Therefore, this study provides a contraindication to AAS use, especially in those at increased risk of cardiovascular events.