Concurrent Resistance Training Research Articles

The Effect of Time-Equated Concurrent Training Programs in Resistance-Trained Men.

The purpose of this investigation was to compare the effects of three different concurrent training (CT) programs and a resistance training (RT) program. Twenty-three resistance trained men (age: 24 ± 3 years) were randomized into four groups: concurrent RT and high intensity interval cycling (CTH, n = 6), concurrent RT and moderate intensity continuous cycling (CTM, n = 5), RT and barbell circuit training (RTC, n = 6), or RT only (RT, n = 6). Back squat and bench press strength, quadriceps, and pectoralis muscle thickness, VO2peak, and maximum workload (Wmax, Watts) were assessed. Squat strength gains were meaningful in all groups and comparable among CTH (16.88 kg [95% CrI: 11.15, 22.63]), CTM (25.54 kg [95% CrI: 19.24, 31.96]), RTC (17.5 kg [95% CrI: 11.66, 23.39]), and RT (20.36 kg [95% CrI: 15.29, 25.33]) groups. Bench press strength gains were meaningful in all groups and comparable among CTH (11.86 kg [95% CrI: 8.28, 15.47]), CTM (10.3 kg [95% CrI: 6.49, 14.13]), RTC (4.84 kg [95% CrI: 1.31, 8.47]), and RT (10.16 kg [95% CrI: 7.02, 13.22]) groups. Quadriceps hypertrophy was meaningful in all groups and comparable among CTH (2.29 mm [95% CrI: 0.84, 3.76]), CTM (3.41 mm [95% CrI: 1.88, 4.91]), RTC (2.6 mm [95% CrI: 1.17, 4.05]), and RT (2.83 mm [95% CrI: 1.55, 4.12]) groups. Pectoralis hypertrophy was meaningful in CTH (2.29 mm [95% CrI: -0.52, 5.1]), CTM (5.14 mm [95% CrI: 2.1, 8.15]), and RTC (7.19 mm [95% CrI: 4.26, 10.02]) groups, but not in the RT group (1 mm [95% CrI: -1.59, 3.59]); further, between-group contrasts indicated less pectoralis growth in the RT compared to the RTC group. Regarding cardiovascular outcomes, only the RTH and RTM groups experienced meaningful improvements in either measure (VO2peak or Wmax). These data suggest that the interference effect on maximal strength and hypertrophy can be avoided when the aerobic training is moderate intensity cycling, high intensity cycling, or a novel barbell circuit for ~one hour per week and on non-RT days. However, the barbell circuit failed to elicit meaningful cardiovascular adaptations.

The effect of concurrent high-intensity interval training and resistance training on the lower body maximal strength and explosive power: A updated systematic review and meta-analysis

BACKGROUND: Endurance training can have a negative impact on strength training and may lead to reduced strength gains, known as the interference effect. However, high-intensity interval training (HIIT) as an endurance training mode may reduce this interference effect. OBJECTIVE: This systematic review and meta-analysis aim to investigate the effects of concurrent HIIT and resistance training (RT) on lower body explosive strength and maximum strength. METHODS: Five electronic databases were searched. Subgroup analyses were performed to assess the effects of HIIT modality, training status, and training duration on strength development following concurrent HIIT and RT. RESULTS: Meta-analysis showed that compared to RT alone, concurrent HIIT and RT will not affect the development of countermovement jump (CMJ) (WMD =-0.17, 95%CI =-1.45 to -1.11) and half squat (WMD =-0.05, 95%CI =-2.42 to 2.32). Further, subgroup analysis revealed that HIIT-running workout was conducive to the development of both CMJ and half squat. Longer training duration was found to be more effective in developing CMJ, while shorter training duration was more suitable for developing half squat. Additionally, athletes showed greater improvement than non-athletes. CONCLUSIONS: Combining HIIT and RT can enhance CMJ and half squat. The results of intervention are moderated by training variables and training status.

Muscular Adaptations to Concurrent Resistance Training and High-Intensity Interval Training in Adults with Type 2 Diabetes: A Pilot Study.

This pilot study aimed to compare the effects of eight weeks of concurrent resistance training (RT) and high-intensity interval training (HIIT) vs. RT alone on muscle performance, mass and quality in adults with type 2 diabetes (T2DM). Twelve T2DM adults were randomly allocated to the RT + HIIT (n = 5) or RT (n = 7) group. Before and after training, maximal oxygen uptake (VO2max), muscle strength and power were evaluated by calorimetry, dynamometry and one-repetition maximum (1RM) test. Quadriceps muscle volume was determined by MRI, and muscle quality was estimated. After RT, VO2max (+12%), knee muscle power (+20%), quadriceps muscle volume (+5.9%) and quality (leg extension, +65.4%; leg step-up, +223%) and 1RM at leg extension (+66.4%), leg step-up (+267%), lat pulldown (+60.9%) and chest press (+61.2%) significantly increased. The RT + HIIT group improved on VO2max (+27%), muscle volume (+6%), muscle power (+9%) and 1RM at lat pulldown (+47%). No other differences were detected. Among groups, changes in muscle quality at leg step-up and leg extension and VO2max were significantly different. The combination of RT and HIIT effectively improves muscle function and size and increases cardiorespiratory fitness in adults with T2DM. However, HIIT combined with RT may interfere with the development of muscle quality.

Omega-3 polyunsaturated fatty acids in sarcopenia management: A network meta-analysis of randomized controlled trials.

Sarcopenia frequently occurs with aging and leads to major adverse impacts on activities of daily living and quality of life in elderly individuals. Omega-3 polyunsaturated fatty acid (omega-3 PUFAs) supplements are considered promising therapeutic agents for sarcopenia management; however, the evidence remains inconsistent. We reviewed randomized controlled trials (RCTs) about omega-3 PUFA supplementation in patients with sarcopenia or in those at high risk for sarcopenia. Network meta-analysis (NMA) procedures were conducted using a frequentist model. The primary outcomes were (1) upper-extremity muscle strength and (2) lower-extremity physical function. The NMA of 16 RCTs showed that the high-dose (more than 2.5g/day omega-3 PUFAs) group yielded the greatest improvement in both upper-extremity muscle strength and lower-extremity physical function [compared to placebo/standard care groups, standardized mean difference (SMD)=1.68, 95% confidence interval (95%CI)=0.03-3.33, and SMD=0.73, 95%CI=0.16-1.30, respectively], and the effects were reaffirmed in subgroup analyses of placebo-controlled RCTs or those excluding concurrent resistance training programs. None of the investigated omega-3 PUFAs supplementation was associated with significantly increased skeletal muscle mass, fat mass, or overall body weight. Our findings provide a basis for future large-scale RCTs to investigate the dose effects and clinical application of omega-3 PUFA supplementation in sarcopenia management. TRIAL REGISTRATION: The current study was approved by the Institutional Review Board of the Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (TSGHIRB No. B-109-29) and registered in PROSPERO (CRD42022347161).

Effect of Concurrent Resistance Training on Lower Body Strength, Leg Kick Swimming, and Sport-Specific Performance in Competitive Swimmers.

Simple SummaryResistance training in and out of the water aims to improve swimming performance. Previous studies have shown that dry land resistance training has positive effects on improving strength and therefore this could optimize swimming performance. The present study investigated the effect of 9 weeks of combined resistance training (aquatic and dry land resistance) on maximum lower body strength, leg kick, and swimming performance in competitive swimmers. The results demonstrated that 9 weeks of combined resistance training could improve the maximum lower body strength and leg kick swimming performance. These improvements can be the essential factors that subsequently positively affected swimming start and turn performance.The present study investigated the effect of 9 weeks of combined resistance training (aquatic and dry land resistance) on maximum lower body strength, leg kick, and swimming performance in competitive swimmers. Twenty-two male national competitive swimmers were randomly assigned into two groups: experimental group (EG: age = 16.2 ± 0.3 years) or control group (CG: age = 16.3 ± 0.3 years). The EG performed a combined resistance training while the CG group completed their usual training. One repetition maximum (1RM) back squat, 30 m leg kick, and swimming performance (100 m front crawl, start and turn) were evaluated in pre and post test. The findings showed a significant increase in 1RM back squat (d = 1.90; 14.94 ± 1.32%) after 9 weeks of combined resistance training. In addition, ours results revealed a significant improvement in 30 m leg kick swimming (d = 2.11; 5.84 ± 0.16%) and in all swimming, start and turn performances (d = 1.83 to 2.77; 2.69 ± 0.18% to 15.14 ± 1.06%) in EG. All dependent variables remained unchanged in the CG. To sum up, 9 weeks of combined resistance training can improve the maximum lower body strength and leg kick swimming performance. These improvements can be the essential factors that subsequently positively affected swimming, start and turn performances. Combined resistance training is an effective training that can be incorporated by coaches and swimmers into their programs to improve strength, leg kick swimming, and, subsequently, swimming performance in competitive swimmers.

Effects of Resistance Training Cessation on Cycling Performance in Well-Trained Cyclists: An Exploratory Study.

Bláfoss, R, Rikardo, J, Andersen, AØ, Hvid, LG, Andersen, LL, Jensen, K, Christensen, PM, Kvorning, T, and Aagaard, P. Effects of resistance training cessation on cycling performance in well-trained cyclists: an exploratory study. J Strength Cond Res 36(3): 796-804, 2022-Supplementary (i.e., concurrent) resistance training can enhance cycling performance among competitive cyclists. However, a lack of knowledge exists about the retention (decay profile) in mechanical muscle function and cycling performance after concurrent resistance and endurance training. The present exploratory intervention study investigated the effect of 6 weeks of resistance training cessation when preceded by 8 weeks of concurrent resistance and endurance training on mechanical muscle function and cycling performance in 9 male well-trained competitive cyclists (V̇o2max = 66 ± 7 ml·min-1·kg-1). Cyclists performed periodized resistance training targeting leg and core muscles for 8 weeks as a supplement to their normal endurance (cycling) training. This was followed by 6 weeks of endurance training only (retention period) leading up to the start of the competitive season. Maximal leg extensor power, isometric leg extensor strength (maximal voluntary contraction [MVC]), rate of force development (RFD), and long-term cycling performance (2-hour submaximal cycling at 55% of Wmax), followed by 5-minute max cycling were evaluated. After 8 weeks of concurrent resistance and endurance training, leg extensor power, MVC, and RFD increased by 12, 15, and 17%, respectively while mean power output (W) during 5-minute max cycling increased by 7% (p < 0.05). Training-induced gains in MVC and 5-minute max cycling power were retained after 6-week cessation of resistance training (p < 0.05). These findings indicate that competitive cyclists can focus on cycling training alone for at least 6 weeks leading up to competition without losing attained gains in maximal muscle strength and cycling performance achieved by preceding periods of concurrent resistance training.

The Effect of Concurrent Resistance Training on Upper Body Strength, Sprint Swimming Performance and Kinematics in Competitive Adolescent Swimmers. A Randomized Controlled Trial

This study aimed to examine the effect of 9 weeks of concurrent resistance training (CRT) between resistance on dry land (bench press (BP) and medicine ball throw) and resistance in water (water parachute and hand paddles) on muscle strength, sprint swimming performance and kinematic variables compared by the usual training (standard in-water training). Twenty-two male competitive swimmers participated in this study and were randomly allocated to two groups. The CRT group (CRTG, age = 16.5 ± 0.30 years) performed a CRT program, and the control group (CG, age = 16.1 ± 0.32 years) completed their usual training. The independent variables were measured pre- and post-intervention. The findings showed that the one-repetition maximum bench press (1RM BP) was improved only after a CRT program (d = 2.18; +12.11 ± 1.79%). Moreover, all sprint swimming performances were optimized in the CRT group (d = 1.3 to 2.61; −4.22 ± 0.18% to −7.13 ± 0.23%). In addition, the findings revealed an increase in velocity and stroke rate (d = 1.67, d = 2.24; 9.36 ± 2.55%, 13.51 ± 4.22%, respectively) after the CRT program. The CRT program improved the muscle strength, which, in turn, improved the stroke rate, with no change in the stroke length. Then, the improved stroke rate increased the swimming velocity. Ultimately, a faster velocity leads to better swim performances.

Concurrent Resistance Training Enhances Performance in Competitive Distance Runners: A Review and Programming Implementation

ABSTRACT Concurrent training, defined as resistance training sessions programmed alongside endurance training sessions during the same cycle, is a tool that highly trained runners can use to augment performance. A review of the current literature explains how resistance training focused on increasing maximal force development and power output can improve running economy, a key performance indicator for endurance running. This review explains the current concepts in concurrent training for competitive distance runners, discusses misconceptions related to concurrent training, and offers practical implementation examples for coaches, athletes, and strength and conditioning practitioners working with this special population.

Effect of beta2 -adrenergic agonist and resistance training on maximal oxygen uptake and muscle oxidative enzymes in men.

While beta2 -adrenoceptor stimulation has been shown to increase lean mass and to alter metabolic properties of skeletal muscle, adaptations in muscle oxidative enzymes and maximal oxygen uptake ( O2max ) in response to beta2 -adrenergic agonist treatment are inadequately explored in humans, particularly in association with resistance training. Herein, we investigated beta2 -adrenergic-induced changes in O2max , leg and arm composition, and muscle content of oxidative enzymes in response to treatment with the selective beta2 -adrenergic agonist terbutaline with and without concurrent resistance training in young men. Forty-six subjects were randomized to 4weeks of lifestyle maintenance (n=23) or resistance training (n=23). Within the lifestyle maintenance and resistance training group, subjects received daily terbutaline (8×0.5mg) (n=13) or placebo (n=10) treatment. No apparent treatment by training interactions was observed during the study period. Terbutaline increased leg and arm lean mass with the intervention, whereas no treatment differences were observed in absolute O2max and incremental peak power output (iPPO). Treatment main effects were observed for O2 -reserve (P<.05), O2max relative to body mass (P<.05), O2max relative to leg lean mass (P<.01), and iPPO relative to leg lean mass, in which terbutaline had a negative effect compared with placebo. Furthermore, content of electron transport chain complex I-V decreased by 11% (P<.05) for terbutaline compared with placebo. Accordingly, chronic treatment with the selective beta2 -adrenergic agonist terbutaline may negatively affect O2max and iPPO in relative terms, but not in absolute.

The compatibility of concurrent high intensity interval training and resistance training for muscular strength and hypertrophy: a systematic review and meta-analysis

ABSTRACTThe purpose of this systematic review and meta-analysis is to assess the effect of concurrent high intensity interval training (HIIT) and resistance training (RT) on strength and hypertrophy. Five electronic databases were searched using terms related to HIIT, RT, and concurrent training. Effect size (ES), calculated as standardised differences in the means, were used to examine the effect of concurrent HIIT and RT compared to RT alone on muscle strength and hypertrophy. Sub-analyses were performed to assess region-specific strength and hypertrophy, HIIT modality (cycling versus running), and inter-modal rest responses. Compared to RT alone, concurrent HIIT and RT led to similar changes in muscle hypertrophy and upper body strength. Concurrent HIIT and RT resulted in a lower increase in lower body strength compared to RT alone (ES = −0.248, p = 0.049). Sub analyses showed a trend for lower body strength to be negatively affected by cycling HIIT (ES = −0.377, p = 0.074) and not running (ES = −0.176, p = 0.261). Data suggests concurrent HIIT and RT does not negatively impact hypertrophy or upper body strength, and that any possible negative effect on lower body strength may be ameliorated by incorporating running based HIIT and longer inter-modal rest periods.

Enhanced skeletal muscle ribosome biogenesis, yet attenuated mTORC1 and ribosome biogenesis-related signalling, following short-term concurrent versus single-mode resistance training

Combining endurance training with resistance training (RT) may attenuate skeletal muscle hypertrophic adaptation versus RT alone; however, the underlying mechanisms are unclear. We investigated changes in markers of ribosome biogenesis, a process linked with skeletal muscle hypertrophy, following concurrent training versus RT alone. Twenty-three males underwent eight weeks of RT, either performed alone (RT group, n = 8), or combined with either high-intensity interval training (HIT+RT group, n = 8), or moderate-intensity continuous training (MICT+RT group, n = 7). Muscle samples (vastus lateralis) were obtained before training, and immediately before, 1 h and 3 h after the final training session. Training-induced changes in basal expression of the 45S ribosomal RNA (rRNA) precursor (45S pre-rRNA), and 5.8S and 28S mature rRNAs, were greater with concurrent training versus RT. However, during the final training session, RT further increased both mTORC1 (p70S6K1 and rps6 phosphorylation) and 45S pre-rRNA transcription-related signalling (TIF-1A and UBF phosphorylation) versus concurrent training. These data suggest that when performed in a training-accustomed state, RT induces further increases mTORC1 and ribosome biogenesis-related signalling in human skeletal muscle versus concurrent training; however, changes in ribosome biogenesis markers were more favourable following a period of short-term concurrent training versus RT performed alone.

Effects of Resistance and Aerobic Exercise Training or Education Associated with a Dietetic Program on Visfatin Concentrations and Body Composition in Overweight and Obese Women

Background: Obesity, as a chronic disease, is becoming increasingly prevalent especially among women. Objectives: The purpose of this study was to evaluate and compare the effects of resistance training (RT), concurrent resistance training and aerobic training (RT + AT) on visfatin concentrations and body composition in overweight and obese women. Methods: An eight-week pretest-posttest design with two experimental exercising groups and one control group was used. 45 overweight and obese women were randomized into resistance training (RT), concurrent resistance and aerobic training (RT + AT) or an education-only groups (EDU). All participants received a dietary and education/counselling intervention. However, only the RT and RT + AT group participated in the eight-week exercise training. Results: Repeated measures analysis showed that visfatin was significantly decreased by 8.5% in the RT (P = 0.02) and 29.2% in the RT + AT (P < 0.001), but not in EDU (3.7%; P = 0.22). BMI was decreased in the RT (6.8%; P < 0.001), RT + AT (8.1%; P < 0.001) and EDU (4.4%; P < 0.001), while BF% decreased in the RT (6.9%; P = 0.001), RT + AT (13.1%; P= 0.001), and EDU (4.9%; P = 0.020). WHR was decreased in the RT (2.4%; P = 0.001), in the RT + AT (4.2%; P = 0.002) and EDU (2.5%; P = 0.02). VO2max (mL.kg-1.min-1) increased in the RT (16.3%; P = 0.004), RT + AT (37.7%; P = 0.001), but not in EDU (7.2%; P = 0.72). The absolute value of VO2max (L.min-1) also significantly increased in RT + AT (0.25%; P < 0.05) compared to baseline, but did not differ between the groups. Conclusions: While RT and education-alone improved body composition and aerobic capacity, structured regular exercise incorporating both RT and AT may be required to improve visfatin and VO2max in overweight and obese females.

The interaction effects of resistance training and sustanon abuse on liver antioxidant activities and serum enzymes in male rats.

BackgroundAnabolic–androgenic steroids (AAS) are synthetic drugs derived from testosterone, the uncontrolled usage of which may lead to serious side effects. Previous studies have shown that resistance training (RT) is the main exercise modality practiced by AAS abusers. Thus, this work was carried out to evaluate the hepatotoxic effects of sustanon (Su) as an example of AAS in trained male rats.MethodsRats were divided into sedentary/non-Su, sedentary/Su, RT/non-Su, and RT/Su. Su-administration groups received Su 10 mg/kg intramuscularly once a week for 8 weeks. In the 8-week RT, the rats climbed a vertical ladder 3 days/week.ResultsAfter Su administration, the mean values of serum parameters related to hepatic function were within normal ranges. Superoxide dismutase, glutathione peroxidase, and glutathione reductase activities were higher (P < 0.05) in the liver of Su-treated rats. Chronic exercise alone did not change any of the above parameters.ConclusionsThe present findings suggest that the 8-week injection of Su, either with or without concurrent RT upregulation of enzymatic antioxidant activities and RT, did not attenuate the increase of enzymatic activities due to the Su administration. Furthermore, Su abuse in this dose did not make any severe liver damage.

EFFECT OF LEUCINE-RICH WHEY PROTEIN AS COMPARED TO SOY PROTEIN ON MUSCLE FUNCTION IN ELDERLY INDIVIDUALS WITH OSTEOPENIA. A FOUR MONTH RANDOMIZED STUDY

Objective: This investigation was conducted to determine whether dietary supplementation with a specific leucine-rich whey protein compound improves physical function and muscle strength in osteopenic elderly people compared to soy protein and placebo. Design, participants and setting: The study was a 16-week randomized single blinded placebo controlled intervention, including 47 women and 10 men from 60-85 years of age with osteopenia (T-score &lt; -1.0 by dual energy X-ray absorptiometry scan). The subjects were assigned to three groups in 2:2:1 relations, daily receiving 1) whey (45.8 g protein including 6.14 g leucine (n=24)), 2) soy (45.9 g protein with 3.1 g leucine (n=23)), and 3) isocaloric placebo with maltodextrin (n=10). A home based resistance training protocol (3 x 45 min / week) was followed by all groups concurrently. The primary focus of the study was on the differences between the two protein groups. Measurements: Physical function was determined by six-minute walk (6MW) and four-meter gait speed (4MGS) tests as primary endpoints, and strength (maximum voluntary contraction) by hand grip, leg extension and -flexion as secondary endpoints. Results: 6MW increased significantly in the whey group compared to the soy group (4% as compared to 1% increment, P &lt; 0.05) but no changes were found in 4MGS. There were no differences between any groups in other variables such as in the strength and balance tests. However, p-urate was significantly lower after whey protein as compared to soy (P &lt; 0.01). Conclusions: Four months of leucine-rich whey protein supplementation and concurrent resistance training significantly increased the six-minute walk test in elderly individuals as compared to soy protein. However, whether this minor increment in the walk test is of clinical importance is unknown. There was no effect on the four-meter gait speed or any other secondary muscle function-related endpoints.

Concurrent Resistance Training and Flying 200-Meter Time Trial Program for a Masters Track Cyclist

Concurrent Resistance Training and Flying 200-Meter Time Trial Program for a Masters Track Cyclist

The Effects of Resistance Training on Road Cycling Performance Among Highly Trained Cyclists: A Systematic Review

Highly trained cyclists may be hesitant to incorporate resistance training (RT) with their endurance training (ET) because of the mixed data regarding concurrent RT and ET (CT). The purpose of this review was to search the scientific body of literature for randomized controlled trials (RCTs) of CT on road cycling performance for highly trained cyclists. Key words (including cycling and strength training) were used to search relevant databases through September 2009 for literature related to CT. Randomized controlled trials were included if they scored > or =5 on the Physiotherapy Evidence Database scale. Five studies met the inclusion criteria: highly trained road cyclists (>7 h.wk or > 150 km.wk, with at least 6 months of training), outcome measure was cycling performance (time trial or time to exhaustion), and RT performed off-bike. Two of the 5 studies found no improvement in performance with CT, but these studies added RT on top of the athletes' existing ET. The 3 studies with improved cycling performance replaced a portion of the athletes' ET with RT, and 2 of the 3 studies included high-intensity explosive-type resistance exercises. Despite the limited research on CT for highly trained cyclists, it is likely that replacing a portion of a cyclist's ET with RT will result in improved time trial performance and maximal power.

Comparison of Resistance and Concurrent Resistance and Endurance Training Regimes in the Development of Strength

Resistance and endurance training are often performed concurrently in most exercise programs and in rehabilitative settings in an attempt to acquire gains in more than 1 physiologic system. However, it has been proposed that by simultaneously performing these 2 modes of exercise training, the strength gains achieved by resistance training alone may be impaired. Thus, the aim of this study was to compare the effects of 16 weeks of resistance training and concurrent resistance and endurance training on muscular strength development in 38 sedentary, apparently healthy males (25 yr +/- 8 mo). Subjects were age-matched and randomly assigned to either a control (Con) group (n = 12), resistance training (Res) group (n = 13), or concurrent resistance and endurance training (Com) group (n = 13). After 16 weeks, no changes were found in the strength of the subjects in the Con group. Resistance training and concurrent resistance and endurance training significantly (p < or = 0.05) improved strength in all of the 8 prescribed exercises. The data also indicated that 16 weeks of concurrent resistance training and endurance training was as effective in eliciting improvements in strength as resistance training alone in previously sedentary males. As such, concurrent resistance and endurance training does not impede muscular strength gains and can be prescribed simultaneously for the development of strength in sedentary, apparently healthy males and thus may invoke all the physiologic adaptations of resistance and endurance training at once.

Comparison of Two Lower-Body Modes of Endurance Training on Lower-Body Strength Development While Concurrently Training

The most recent American College of Sports Medicine (1998) recommendations for quantity and quality of exercise includes both resistance and endurance exercise components. Skeletal muscle adaptations to resistance-only and endurance-only programs may be different and possibly antagonistic when both types of training are imposed concurrently. The present study examined the effect of two different modes of lower-body endurance exercise (i.e., cycle ergometry and incline treadmill walking) on lower-body strength development with concurrent resistance training designed to improve lower-body strength (i.e., bilateral leg press 1 repetition maximum [RM]). Thirty untrained participants (22 men and 8 women, ages 18-23) were randomly assigned to one of 3 training groups (resistance only [R], N = 10; resistance + cycle ergometry [RC], N = 10; and resistance + incline treadmill [RT], N = 10). The 3 training groups exercised twice per week for 9 weeks. The reduced frequency of exercise treatments were selected specifically to avoid overtraining for in-season athletes attempting to maintain offseason conditioning. Body mass and body composition measurements were taken pre- and post-training. Before training began, 3 weeks of training, 6 weeks of training, and after training, the participants also performed a 1RM test for lower-body strength. Analysis of variance comparisons with repeated measures revealed the following statistically significant changes (alpha = 0.05) in the 3 training groups over time: (a) when men and women were combined, body mass of R was significantly greater than RC and RT post-training; (b) body mass of men only was significantly greater than RC and RT post-training; (c) body composition of men only was significantly smaller for RC and RT compared with R; (d) when men and women were combined, percent change in strength revealed significantly greater gains in R compared with RT at 6 weeks; (e) when men and women were combined, percent change in strength revealed significantly greater gains in R compared with RC and RT post-training; (f) percent change in strength for men only was significantly greater for R compared with RT at 3 weeks; (g) percent change in strength for men only was significantly greater for R compared with RC and RT at 6 weeks, and RC was significantly greater than RT at 6 weeks; (h) percent change in strength in men only was significantly greater for R compared with RC and RT post-training, and RC was significantly greater than RT post-training; and (i) percent change in strength in women was significantly greater in R compared with RT post-training. The findings confirm previous studies that reported attenuated strength development with concurrent resistance and endurance training compared with resistance-only training. More importantly, this study indicates that the mode of endurance exercise in concurrent training regimens may play a role in the development of strength. Specifically, it seems that cycling is superior to treadmill endurance training for an individual with the goal of developing strength in a multijoint movement (i.e., leg press or squat) in the lower-body because it more closely mimics the biomechanical movement of these exercises.

EFFECTS OF CREATINE MONOHYDRATE SUPPLEMENTATION ON BODY COMPOSITION AND STRENGTH INDICES IN EXPERIENCED RESISTANCE TRAINED WOMEN

The purpose of this study was to examine 10 weeks of creatine monohydrate (Cr) supplementation coupled with resistance training on body composition and strength in women trainees. Twenty-six subjects ingested Cr (n = 13) or a placebo (Pl) (n = 13) at a dose of 0.3 g·kg−1 and 0.03 g·kg−1 body mass for the initial 7 days and subsequent 9 weeks, respectively, while performing a resistance training program 4 days per week. Significant increases (p < 0.05) occurred in both groups for lean body mass and 1 repetition maximum (1RM) bench press and incline leg press. There was a significant main effect for training, but there was no significant difference in the total number of repetitions completed after 5 sets of multiple repetitions to exhaustion at 70% of 1RM for bench press and incline leg press for both groups or in the ability to perform a greater training volume (sets × repetitions × load) in the Cr vs. Pl groups over the 10 weeks. The results indicate that Cr supplementation combined with 10 weeks of concurrent resistance training may not improve strength or lean body mass greater than training only. These findings may be a result of nonresponders due to gender differences or a varying biological potential to uptake Cr within the muscle.

Effects of Creatine Monohydrate Supplementation on Body Composition and Strength Indices in Experienced Resistance Trained Women

The purpose of this study was to examine 10 weeks of creatine monohydrate (Cr) supplementation coupled with resistance training on body composition and strength in women trainees. Twenty-six subjects ingested Cr (n = 13) or a placebo (Pl) (n = 13) at a dose of 0.3 g.kg(-1) and 0.03 g.kg(-1) body mass for the initial 7 days and subsequent 9 weeks, respectively, while performing a resistance training program 4 days per week. Significant increases (p < 0.05) occurred in both groups for lean body mass and 1 repetition maximum (1RM) bench press and incline leg press. There was a significant main effect for training, but there was no significant difference in the total number of repetitions completed after 5 sets of multiple repetitions to exhaustion at 70% of 1RM for bench press and incline leg press for both groups or in the ability to perform a greater training volume (sets x repetitions x load) in the Cr vs. Pl groups over the 10 weeks. The results indicate that Cr supplementation combined with 10 weeks of concurrent resistance training may not improve strength or lean body mass greater than training only. These findings may be a result of nonresponders due to gender differences or a varying biological potential to uptake Cr within the muscle.