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Concurrent Training: A Meta-Analysis Examining Interference of Aerobic and Resistance Exercises
Abstract and Figures
The primary objective of this investigation was to identify which components of endurance training (e.g., modality, duration, frequency) are detrimental to resistance training outcomes. A meta-analysis of 21 studies was performed with a total of 422 effect sizes (ESs). Criteria for the study included were (a) compare strength training alone to strength plus endurance training (concurrent) or to compare combinations of concurrent training; (b) the outcome measures include at least one measure of strength, power, or hypertrophy; and (c) the data necessary to calculate ESs must be included or available. The mean ES for hypertrophy for strength training was 1.23; for endurance training, it was 0.27; and for concurrent training, it was 0.85, with strength and concurrent training being significantly greater than endurance training only. The mean ES for strength development for strength training was 1.76; for endurance training, it was 0.78; and for concurrent training, it was 1.44. Strength and concurrent training was significantly greater than endurance training. The mean ES for power development for strength training only was 0.91; for endurance training, it was 0.11; and for concurrent training, it was 0.55. Significant differences were found between all the 3 groups. For moderator variables, resistance training concurrently with running, but not cycling, resulted in significant decrements in both hypertrophy and strength. Correlational analysis identified significant negative relationships between frequency (-0.26 to -0.35) and duration (-0.29 to -0.75) of endurance training for hypertrophy, strength, and power. Significant relationships (p < 0.05) between ES for decreased body fat and % maximal heart rate (r = -0.60) were also found. Our results indicate that interference effects of endurance training are a factor of the modality, frequency, and duration of the endurance training selected.
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... Common endurance training includes continuous training, high-intensity interval training, and lactate threshold intensity training, which often consist of longer endurance training sessions. At present, it is believed that long-term endurance training affects the growth of strength ability, while certain strength training has no obvious effect on endurance ability, and the aerobic and strength concurrent training on endurance ability is less than that of strength ability (Wilson et al., 2012). However, there is still no systematic report on whether the sequence of aerobic and strength training affects endurance ability. ...
... In this study, only Cadore et al. (2013) conducted aerobic running on a treadmill. Wilson et al. (2012) also pointed out in their meta-analysis that cycling training can reduce the incompatible effect of endurance on strength. This may be because running plays a significant role in training practice, and the muscles experience a more eccentric contraction process and stress stimulation to the body (Doma et al., 2019) and this exerts considerable load on the musculoskeletal system. ...
... Concurrent training frequency was shown to affect adaptive responses, with improvements in muscle strength diminishing when strength and endurance training was performed 4-6 times per week (Kraemer et al., 1995). A meta-analysis of 21 articles of 422 people on the effects of concurrent training on strength showed that endurance training no more than thrice a week can effectively reduce the incompatibility of training (Wilson et al., 2012). Similar results were found in this study, when training twice a week, and S-E training showed more advantages in improving lower body strength (SMD = 0.39, 95% CI: 0.13-0.64, ...
The aim of this study is to compare the effects of concurrent strength and endurance training sequences on VO2max and lower limb strength performance to provide scientific guidance for training practice. We searched PubMed, EBSCO, Web of Science (WOS), Wanfang, and China National Knowledge Infrastructure (CNKI) databases up to December 2022. The included articles were randomized controlled trials that allowed us to compare the strength–endurance (S-E) sequence and endurance–strength (E-S) sequence on VO2max, maximum knee extension strength, maximum knee flexion strength, and lower limb power. The Cochrane bias risk tool was used to evaluate the methodological quality of the included literature, and Stata 12.0 was used for the heterogeneity test, subgroup analysis, draw forest map, sensitivity analysis, and publication bias evaluation. The results have been presented as standardized mean differences (SMDs) between treatments with 95% confidence intervals and calculations performed using random effects models. Significance was accepted when p < 0.05. The studies included 19 randomized controlled trials (285 males and 197 females), 242 subjects in S-E sequence, and 240 subjects in E-S sequence in the analyses. No difference changes between S-E and E-S sequences has been observed on VO2max in the overall analysis (SMD = 0.02, 95% CI: −0.21–0.25, p = 0.859). The S-E sequence shows a greater increase in lower limb strength performance than does the E-S sequence (SMD = 0.19, 95% CI: 0.02–0.37, p = 0.032), which was manifested in the elderly (p = 0.039) and women (p = 0.017); in training periods >8 weeks (p = 0.002) and training frequencies twice a week (p = 0.003); and with maximum knee flexion (p = 0.040) and knee extension strength (p = 0.026), while no difference was found in lower limb power (p = 0.523). In conclusion, the effect of VO2max will not change with different concurrent training sequences. The S-E sequence improves lower limb strength more significantly, mainly in the improvement of knee flexion and knee extension. This advantage is more related to factors such as age, gender, training period, and training frequency.
... However, endurance and resistance exercises could also interfere with each other [4] and produce inferior gains in muscular strength compared with resistance exercise alone, giving origin to the so-called "interference effect" [5,6]. Interference occurs when strength and endurance stimuli both target peripheral (i.e., muscular) adaptations (e.g., hypertrophy vs. muscle capillarization) [4] and a meta-analysis confirmed the occurrence of the "interference effect" [6]. ...
... However, endurance and resistance exercises could also interfere with each other [4] and produce inferior gains in muscular strength compared with resistance exercise alone, giving origin to the so-called "interference effect" [5,6]. Interference occurs when strength and endurance stimuli both target peripheral (i.e., muscular) adaptations (e.g., hypertrophy vs. muscle capillarization) [4] and a meta-analysis confirmed the occurrence of the "interference effect" [6]. That is, strength training alone compared to combined training produced larger improvements in muscle strength and power. ...
... The increase in muscle performance observed after a training program including resistance exercises would have been to be intuitively expected, yet it was to be demonstrated, inasmuch as it was imbricated with aerobic exercises, within the biocircuit training, and it has been repeatedly reported that combining aerobic and resistance exercise could reduce the effects on muscle performance induced by resistance exercise, the socalled "Muscle Interference" phenomenon [6,[26][27][28][29][30]. ...
Background:
The best format of exercise training (ET) in the setting of cardiac rehabilitation in patients with chronic heart failure (CHF) is still to be defined. Current guidelines recommend aerobic exercises, such as running and cycling, including some sessions per week of resistance exercise.
Aim:
The aim of this study was to address the effectiveness of a concurrent exercise training program utilizing a circuit of sequential endurance and resistance exercises on functional capacity and muscular strength in patients with CHF.
Methods:
Ninety-five consecutive male patients (age 63.1 ± 6 years) with CHF (EF < 40%) in NYHA functional class II/III, were randomly assigned on 1:1 basis to a 12-week aerobic continuous training (AT) or concurrent CT), aerobic + resistance, training (CT), three times a week, with each session lasting 80 min. We used high quality, specifically designed ergometers, connected with each other and governed by a central console, and managed by a single physiotherapist. Before and after training all patients performed a symptoms-limited exercise test on a treadmill and a 6-min walking test (6MWT). Patients in the CT group also performed resistance exercises of upper and lower body.
Results:
The 6MWT and exercise duration at ergometric test increased significantly in both AT and CT groups, with the increase being greater in CT group (p < 0.001; ES = 0.13; p < 0.01; ES = 0.07). Muscular strength increased significantly in the CT group, particularly in the lower body muscular districts (p < 0.001). Quality of life improved in both groups, with a significantly greater improvement in the CT group (p < 0.05). No side effects leading to discontinuation of training were observed.
Conclusions:
These findings indicate that concurrent, within-session training results in larger improvements in functional capacity, in addition to muscle performance, in patients with CHF, in comparison to single-mode aerobic training.
... The anti-inflammatory benefits of regular exercise may be mediated by both a decrease in visceral fat mass (by lowering the production of adipokines) and the development of an anti-inflammatory milieu after exercise bouts [15]. ET and RT are frequently prescribed to reduce inflammatory-related disease risk [13]; however, incorporating RT and ET simultaneously in the same training period-also known as combined training or concurrent training (CT) [16,17]-may further enhance the anti-inflammatory benefits of regular exercise [18]. To our knowledge, a single study has measured biomarkers of the CTRP family after exercise. ...
Aim:
Previous studies have focused on the order of endurance and resistance training when performing concurrent training (CT). However, no study has compared the effects of combined training with CT orders on inflammatory markers, muscular performance, and body composition in overweight and obese males. Therefore, the purpose of the current study was to compare the effects of 12 weeks of CT and combined training on the aforementioned markers in overweight and obese males.
Methods:
Sixty middle-aged overweight and obese males (age 51 ± 4 years) were randomly assigned into one of four groups: endurance followed by resistance training (ER; n = 15), resistance followed by endurance training (RE; n = 15), combined resistance and endurance training (COM), or control (CON; n = 15). Anthropometric, body composition, inflammatory marker, and muscular performance measurements were collected at baseline and after 12 weeks.
Results:
FFM remained unchanged in all three intervention groups (p > 0.05). Reductions in FM in the RE group were significantly greater than in CON (p = 0.038). The increases in serum concentrations of adiponectin in the RE group were significantly greater than in all other groups (p < 0.05). Increased serum concentrations of CTRP3 in all intervention groups were significantly greater than the CON group (p < 0.05); moreover, the increases in the RE group were significantly greater than CON (p < 0.001). Regarding CTRP5, the increase in RE was significantly greater than COM (p = 0.014). The RE group experienced significantly greater increases in CTRP9 than all other groups (p < 0.05), and the decreases in serum concentrations of CRP and TNF-α were significantly greater in the RE group compared to CON and ER (p < 0.05). Vo2max in the ER group was significantly greater than COM (p = 0.009), and all interventions resulted in higher gains compared to CON (p < 0.05). The increases in leg press strength, chest press strength, lower-body power, and upper-body power in the RE group were significantly greater than in the COM group (p < 0.05). In addition, the increases in chest press strength in the ER group were significantly greater than COM (p = 0.023).
Conclusions:
Regardless of training order, CT improved inflammatory markers, body composition, power, and VO2max. Notably, our analysis indicated significantly greater improvements in adiponectin, CTRP5, CTRP9, CRP, and TNF-α levels when RT preceded ET in CT sessions compared to other exercise training sequences. These findings suggested that the order of exercise training may have a significant impact on the effectiveness of CT on inflammatory markers, which has potential implications for exercise prescription and optimization of health-related training outcomes.
... Porém, as adaptações específicas decorrentes desse tipo de treinamento podem não trazer tantos benefícios para o desempenho de atletas em esportes de endurance (FLECK;KRAEMER, 2006). Os efeitos do treinamento concorrente estão relacionados com as diferentes interações entre as respostas e adaptações desse tipo de treinamento e estão associadas a grandes volumes ou intensidades, longa duração e tipo de treinamento(WILSON et al., 2011).O treinamento de força contribui para a melhora da biomecânica do movimento na corrida e da performance, através da melhora da capacidade física da força, da potência e na melhora do equilíbrio, aumentando a estabilidade articular e postural e contribuindo com a prevenção de lesões ligamentares em membros inferiores, Além disso, o treinamento de força combinado com exercícios de proprioceptivos ajudam a reduzir lesões ligamentares nos joelhos em atletas do sexo feminino(PATERNO et al., 2004;MYER et al., 2006).O treinamento de força apresentou-se como uma melhor estratégia preventiva, ao ser comparado com o treinamento que propriocepção e outros métodos de treinamento, e foi significativamente melhor que outros treinamentos combinados (Força e Endurance), reduzindo as lesões em menos de um terço (LAUERSEN et al., 2014). Para Badillo e Ayestarán (2001), os atletas de esportes de resistência podem se beneficiar com o treinamento de força com o objetivo de prevenir lesões e melhorar o seu rendimento esportivo ao mesclar treinamentos de força junto com os treinamentos de resistência, pois as adaptações geradas por esses tipos de treino promovem uma melhora das capacidades de contração muscular, otimizam a energia elástica armazenada no músculo, flexibilidade e traz uma melhora da mecânica de corrida e das capacidades anaeróbias do corredor de endurance. ...
A corrida de rua é hoje um dos esportes mais praticados no mundo, sendo a grande maioria atletas amadores, e muitos deles buscam, assim como atletas profissionais, uma forma de melhorar a biomecânica da corrida e consequentemente a sua performance para se ter menos desgastes em suas provas. Várias são as metodologias de treinamento para atingir esse objetivo, uma dessas formas é o treinamento de força, que tem se mostrado importante para a melhora da performance dos atletas, diminuindo a incidência de lesões e melhorando o rendimento. O objetivo desse trabalho é analisar na literatura as várias metodologias de treinamento de força e sua relação com a melhora da biomecânica da corrida, dando ênfase em possíveis benefícios na economia da corrida de rua. Os resultados mostraram que o treinamento de força se mostrou importante para a melhoria de desempenho de corredores de endurance. Melhoria essa que parece estar relacionada às adaptações neuromusculares geradas pelo treinamento de força, independente das manifestações e tipos de forças treinadas.
Background Head and Neck Cancer (HNC) is a globally rare cancer that includes a variety of tumors affecting the upper aerodigestive tract. It presents with difficulty breathing or swallowing and is mainly treated with radiation therapy, chemotherapy, or surgery for tumors that have spread locally or throughout the body. Alternatively, exercise can be used during cancer treatment to improve function, including pain relief, increase range of motion and muscle strength, and reduce cancer-related fatigue, thereby enhancing quality of life. Although existing evidence suggests the adjunctive use of exercise in other cancer types, no previous studies have examined the effects of this therapy in HNC survivors. The aim of this meta-analysis was to quantify the effect of exercise-based rehabilitation on functionality and quality of life in HNC survivors who underwent surgery and/or chemoradiotherapy. A systematic review and meta-analysis were carried out following PRISMA statement and registered in PROSPERO (CRD42023390300). Search was performed in MEDLINE (PubMED), Cochrane Library, CINAHL and Web of Science (WOS) databases from inception to 31st December 2022 using the terms “ cancer ”, “ head and neck neoplasms ”, “ exercise ”, “ rehabilitation ”, “ complications ”, “ muscle contraction ”, “ muscle stretching exercises ” combining with booleans “AND”/ “OR”. PEDro scale, Cochrane Risk of Bias Tool and GRADE were used to assess methodological quality, risk of bias and grade of recommendation of included studies respectively. 18 studies (n = 1322) were finally included which 1039 (78.6%) were men and 283 (21.4%) were women. In patients underwent radio-chemotherapy, overall pain [SMD=-0.62 [-4.07, 2.83] CI 95%, Z = 0.35, P = 0.72] and OP [SMD=-0.07 [-0.62, 0.48] CI 95%, Z = 0.25, p = 0.81] were slightly reduced with exercise in comparison to controls. Besides, lower limb muscle strength [SMD=-0.10 [-1.52, 1.32] CI 95%, Z = 0.14, p = 0.89] and fatigue [SMD=-0.51 [-0.97, -0.057] CI 95%, Z = 2.15, p < 0.01] were also improved in those who receive radio-chemoradiation. In HNC survivors treated with neck dissection surgery, exercise was superior to controls in overall pain [SMD=-1.04 [-3.31, 1.23] CI 95%, Z = 0.90, p = 0.37] and, in mid-term, on shoulder pain SMD=-2.81 [-7.06, 1.43] CI 95%, Z = 1.76, p = 0.08]. No differences in quality of life were found at any of the follow-up periods. There is evidence of fair to good methodological quality, low to moderate risk of bias, and weak recommendation supporting the use of exercise-based rehabilitation to increase functionality. However, no evidence was found in favor of the use of this modality for improving the quality of life of HNC survivors who underwent chemoradiotherapy or surgery. The lack of standardization in the development of exercise programs, the diversity of randomized trials, and the heterogeneity of interventions and evaluations warrant further study.
Background
While therapeutically effective, chemoradiotherapy treatment for high grade glioma (glioblastoma) is often accompanied by side effects. Exercise has been demonstrated to alleviate adverse effects of such treatments in other cancers. We aimed to evaluate feasibility and preliminary efficacy of supervised exercise incorporating autoregulation.
Methods
Thirty glioblastoma patients were recruited, five declined exercise and 25 were provided with a multi-modal exercise intervention for the duration of their chemoradiotherapy treatment. Patient recruitment, retention, adherence to training sessions and safety were evaluated throughout the study. Physical function, body composition, fatigue, sleep quality and quality of life were evaluated before and after the exercise intervention.
Results
Eight of the 25 participants commencing exercise withdrew prior to completion of the study (32%). Seventeen patients (68%) demonstrated low to high adherence (33% - 100%) and exercise dosage compliance (24% - 83%). There were no reported adverse events. Significant improvements were observed for all trained exercises and for lower limb muscle strength and function with no significant changes observed for any other physical function, body composition, fatigue, sleep, or quality of life outcomes.
Conclusions
Only half of glioblastoma patients recruited were willing or able to commence, complete or meet minimum dose compliance for the exercise intervention during chemoradiotherapy indicating the intervention evaluated may not be feasible for part of this patient cohort. For those who were able to complete the exercise program, supervised, autoregulated, multi-modal exercise was safe and significantly improved strength and function and may have prevented deterioration in body composition and quality of life.
Introduction
Metabolic flexibility (MetF) is the capacity of an organism to oxidate substrate according to substrate availability or demand. The mismatch of substrate availability and oxidation may cause ectopic fat accumulation in the muscle and the liver. The objectives of the study are to examine the effect of 12 weeks of combined exercise on hepatic fat reduction and investigate metabolites related to MetF before and after the high-fat diet between individuals with NAFLD and healthy control with an active lifestyle.
Methods
This study is an open-label, single-center trial randomized controlled clinical study plus a cross-sectional comparison between individuals with NAFLD and healthy control. Individuals with NAFLD were allocated into two groups receiving resistance training (RT) combined with high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT). Anthropometric indicators, clinical blood markers about glucose, lipid metabolism, and hepatic fat content (HFC) were assessed before and after the intervention. The metabolomics was also used to investigate the discrepant metabolites and mechanisms related to MetF.
Discussion
Metabolic flexibility reflects the capacity of an organism to switch the oxidation substrates flexibly, which is associated with ectopic fat accumulation. Our study aimed to explore the discrepant metabolites related to MetF before and after a high-fat diet between individuals with NAFLD and healthy control. In addition, the study also examined the effectiveness of RT combined with HIIT or MICT on hepatic fat reduction and quantificationally analyzed the metabolites related to MetF before and after the intervention. Our results provided a perspective on fatty liver-associated metabolic inactivity.
Trial registration
ClinicalTrials.gov : ChiCTR2200055110; Registered 31 December 2021, http://www.chictr.org.cn/index.aspx .
Background:
The aim of this study was to examine associations of total volume and bouts of sedentary time (ST) and moderate to vigorous physical activity (MVPA) with physical fitness (PF) in youth.
Methods:
This was a 2-year follow-up study with 1418 children and adolescents (51.7% boys). Accelerometers were used to assess ST and MVPA. Cardiorespiratory and muscular fitness values were objectively measured and combined in a global PF variable. Weight status was objectively obtained. Linear regression analyses were used to examine the cross-sectional (using scores at baseline) and longitudinal associations (using the change in the variables) of total volume and bouts of ST and MVPA with PF.
Results:
Total ST was negatively associated with global PF (β = -0.488, P < .001 in cross-sectional analysis; β = -0.234, P = .003 in longitudinal analysis). However, this association was not independent of MVPA. Total volume of MVPA showed a positive association with global PF independently of ST and weight status (β = 0.285, P < .001 in cross-sectional analysis; β = 0.119, P = .001 in longitudinal analysis). Longitudinal associations found between ST and MVPA accumulated in bouts of various lengths and global PF became nonsignificant when their respective total volumes are included in the model.
Conclusions:
These results underline the need to accumulate minutes of MVPA, regardless of the bout duration, to increase PF levels in youth.
Athletes experience minor fatigue and acute reductions in performance as a consequence of the normal training process. When the balance between training stress and recovery is disproportionate, it is thought that overreaching and possibly overtraining may develop. However, the majority of research that has been conducted in this area has investigated overreached and not overtrained athletes. Overreaching occurs as a result of intensified training and is often considered a normal outcome for elite athletes due to the relatively short time needed for recovery (approximately 2 weeks) and the possibility of a supercompensatory effect. As the time needed to recover from the overtraining syndrome is considered to be much longer (months to years), it may not be appropriate to compare the two states. It is presently not possible to discern acute fatigue and decreased performance experienced from isolated training sessions, from the states of overreaching and overtraining. This is partially the result of a lack of diagnostic tools, variability of results of research studies, a lack of well controlled studies and individual responses to training.
The general lack of research in the area in combination with very few well controlled investigations means that it is very difficult to gain insight into the incidence, markers and possible causes of overtraining. There is currently no evidence aside from anecdotal information to suggest that overreaching precedes overtraining and that symptoms of overtraining are more severe than overreaching. It is indeed possible that the two states show different defining characteristics and the overtraining continuum may be an oversimplification. Critical analysis of relevant research suggests that overreaching and overtraining investigations should be interpreted with caution before recommendations for markers of overreaching and overtraining can be proposed. Systematically controlled and monitored studies are needed to determine if overtraining is distinguishable from overreaching, what the best indicators of these states are and the underlying mechanisms that cause fatigue and performance decrements. The available scientific and anecdotal evidence supports the existence of the overtraining syndrome; however, more research is required to state with certainty that the syndrome exists.
Thirty-five healthy men were matched and randomly assigned to one of four training groups that performed high-intensity strength and endurance training (C; n = 9), upper body only high-intensity strength and endurance training (UC; n = 9), high-intensity endurance training (E; n = 8), or high-intensity strength training (ST; n = 9). The C and ST groups significantly increased one-repetition maximum strength for all exercises (P < 0.05). Only the C, UC, and E groups demonstrated significant increases in treadmill maximal oxygen consumption. The ST group showed significant increases in power output. Hormonal responses to treadmill exercise demonstrated a differential response to the different training programs, indicating that the underlying physiological milieu differed with the training program. Significant changes in muscle fiber areas were as follows: types I, IIa, and IIc increased in the ST group; types I and IIc decreased in the E group; type IIa increased in the C group; and there were no changes in the UC group. Significant shifts in percentage from type IIb to type IIa were observed in all training groups, with the greatest shift in the groups in which resistance trained the thigh musculature. This investigation indicates that the combination of strength and endurance training results in an attenuation of the performance improvements and physiological adaptations typical of single-mode training.
The purpose of this study was to determine how different training modes would influence blood levels of growth hormone (hGH) and selected physiological parameters. Three training groups were established: LIFT, in which subjects trained with free weights and a Universal Gym three times per week with three sets at six to eight repetitions per lift (75 percent of one-repetition maximum) for 10 weeks; RUN, in which subjects ran at 75 percent of HR max three times per week; and COMBO, in which subjects underwent both LIFT and RUN training. Resting hGH levels were determined before and after training, and the hGH response to a single bout of exercise was determined at one, four, eight and 10 weeks. Each subject was tested for one-repetition (1 RM) strength in the bench and leg press during weeks one and 10 of training. Resting and exercise response blood samples were taken from an anticubital vein and centrifuged, and the serum was analyzed for hGH by radioimmunoassay techniques. The results of the hormonal measurements indicate that except for a significant (p < 0.05) decrease in the resting levels of hGH in the LIFT group, training did not alter hGH levels at rest. The 10 weeks of exercise training did not change the basic hGH response to a single bout of exercise in the LIFT and COMBO groups, but did shift the hGH peak of RUN subjects from four to eight minutes by the eighth week of training. The non-hormonal factors affected were: [latin capital V with dot above]O2 max of RUN and COMBO was significantly higher (p < 0.05) above LIFT; LBM and upper body strength of LIFT and COMBO was significantly elevated (p < 0.05) than RUN; and significant gains (p < 0.05) in lower body strength occurred only in LIFT, The data indicate that 10 weeks of exercise training does not significantly alter the basic hGH response to a single bout of exercise, but can influence the appearance of the hormonal peak. The results also show that a training program involving both running and lifting can produce the same gains in [latin capital V with dot above]O2 max and upper body strength as single-activity programs, but does not produce lower body strength gains.
(C) 1991 National Strength and Conditioning Association
The purpose of this investigation was to determine the effects of 7 weeks of concurrent strength and endurance training on the triceps brachii. Fifteen fit subjects were randomly allocated to endurance (TE), strength (TS), or concurrent (TC) training groups. Endurance training involved five 5-min bouts of incremental arm cranking at between 40 and 100% of peak arm ergometer oxygen consumption (P[latin capital V with dot above]O2). Strength training involved two 30-s sets of maximal isokinetic contractions at 4.16 rad [middle dot] sec-1. The TC group completed both strength and endurance training. P[latin capital V with dot above]O2 and strength assessments were conducted prior to and following 2, 5, and 7 weeks of training. Isokinetic strength (T30) was determined 0.52 rad (30[degrees]) from full extension for 10 angular velocities between 0.52 and 5.20 rad [middle dot] sec-1. Two weeks of training significantly increased T30 at all contractile speeds for the TS, TE, and TC conditions. T30 was further increased at all contractile speeds at Weeks 5 and 7 for the TE and TC groups, respectively. Seven weeks of training significantly increased P[latin capital V with dot above]O2 in the TE and TC conditions, but not in the TS group.
(C) 1993 National Strength and Conditioning Association
This study compared the effects of three preseason training programs on endurance, strength, power, and speed. Subjects were divided into four groups: the endurance (E) group completed a running endurance program 4 days [middle dot] week-1; the strength (S) group trained 3 days [middle dot] week-1; the S+E group combined S and E training programs 5 days [middle dot] week-1; the control (C) group did not train. After 8 weeks, the E and S+E groups had similar gains in endurance running performance, the S group had no change, while the C group showed a decline. No strength gains were noted in the C or E groups, but strength gains were made in the S+E and S groups. Power (vertical jump performance) and speed (20-m sprint time) gains were noted only for the S group. These findings show that training for strength alone results in gains in strength, power, and speed while maintaining endurance. S+E training, while producing gains in endurance and upper body strength, compromises gains in lower body strength and does not improve power or speed.
(C) 1994 National Strength and Conditioning Association
Eleven subjects (6 M, 5 F) strength trained 3 times a week for 16 weeks, and 22 subjects (14 M, 8 F) did likewise while also performing endurance training 3 times a week on alternate days. All variables were tested every 4 weeks for 16 weeks. Significant gender differences were observed for bilateral incline leg press and bench press 1-RM, serum testosterone (T), urinary free cortisol (UC), ventilation threshold (VT), and [latin capital V with dot above]O2 max. There was a significant increase in bilateral incline leg press and bench press 1-RM for both training groups and genders. Relative gains in bilateral incline leg press and bench press 1-RM were similar for men. For women the gains in bilateral incline leg press 1-RM, but not bench press, were lower with concurrent training than with strength training only. No significant differences in T were observed with either program. UC was significantly elevated at 8 weeks for men and remained so after concurrent training, but decreased to baseline levels after strength training. UC decreased in the strength training women at 8 weeks but increased for women in both groups at 16 weeks. VT and [latin capital V with dot above]O2 max increased at 16 weeks of concurrent training. This indicates there are differences in strength and hormonal adaptations between men and women with concurrent training and strength training only.
(C) 1997 National Strength and Conditioning Association
Impairment in strength development has been demonstrated with combined strength and endurance training as compared with strength training alone. The purpose of this study was to examine the effects of combining conventional 3 d[middle dot]wk-1 strength and endurance training on the compatibility of improving both [latin capital V with dot above]O2peak and strength performance simultaneously. Sedentary adult males, randomly assigned to one of three groups (N = 10 each), completed 10 wk of training. A strength-only (S) group performed eight weight-training exercises (4 sets/exercise, 5-7 repetitions/set), an endurance-only (E) group performed continuous cycle exercise (50 min at 70% heart rate reserve), and a combined (C) group performed the same S and E exercise in a single session. S and C groups demonstrated similar increases (P < 0.0167) in 1RM squat (23% and 22%) and bench press (18% for both groups), in maximal isometric knee extension torque (12% and 7%), in maximal vertical jump (6% and 9%), and in fat-free mass (3% and 5%). E training did not induce changes in any of these variables. [latin capital V with dot above]O2peak (ml[middle dot]kg-1min-1) increased (P < 0.01) similarity in both E (18%) and C (16%) groups. Results indicate 3 d[middle dot]wk-1 combined training can induce substantial concurrent and compatible increases in [latin capital V with dot above]O2peak and strength performance.
(C)1995The American College of Sports Medicine
The effect of concurrent strength (S) and endurance (E) training on adaptive changes in aerobic capacity, endurance performance, maximal muscle strength and muscle morphology is equivocal. Some data suggest an attenuated cardiovascular and musculoskeletal response to combined E and S training, while other data show unimpaired or even superior adaptation compared with either training regime alone. However, the effect of concurrent S and E training only rarely has been examined in top-level endurance athletes. This review describes the effect of concurrent SE training on short-term and long-term endurance performance in endurance-trained subjects, ranging from moderately trained individuals to elite top-level athletes. It is concluded that strength training can lead to enhanced long-term (>30 min) and short-term (<15 min) endurance capacity both in well-trained individuals and highly trained top-level endurance athletes, especially with the use of high-volume, heavy-resistance strength training protocols. The enhancement in endurance capacity appears to involve training-induced increases in the proportion of type IIA muscle fibers as well as gains in maximal muscle strength (MVC) and rapid force characteristics (rate of force development), while likely also involving enhancements in neuromuscular function.