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Responses of knee extensor muscles to leg press training of various types in human
Abstract
Responses of m. vastus lateralis to 8-week resistive training of various types at leg press mashine were investigated in 30 male subjects. Training loads were 25, 65 and 85% of one repetition maximum for low (LI), medium (MI), and high intensity (HI) training groups respectively, while angular velocities of contraction differed considerably between groups. The total work done during training session was identical. The maximum strengths during isokinetic knee extension in LI and HI groups were increased at most angular velocities. In group MI increments were obtained only during concentric contractions. Significant improvement of fatigue resistance and maximum oxygen consumption (V(O2max)) was seen only in group MI and LI, respectively. The training-related increase of cross-sectional area in type II fibers in m. vastus lateralis was in the order of HI > MI > LI group, and that of type I fibers was opposite. The increased myonuclear number was found for HI group. The data suggest that fiber hypertrophy, fatigue resistance and V(O2max) changes were related to the type of training.
... Reports not retrieved (n = 0) Table 2 shows the characteristics of the participants in the 23 studies that were selected for systematic review regarding the sample size, age, height, weight, and training status (mean ± SD) of the 563 participants, where 454 were untrained (80.6%) [11,[14][15][16][17][21][22][23]26,28,29,[38][39][40][41][42][43][44][45] and 109 were recreationally trained (19.4%) [13,46,47] in resistance training. Table 3 shows the characteristics of the studies that were selected for the systematic review regarding the study design, time of analysis, resistance exercise(s), prescription, weekly frequency, movement tempo, volume, and findings. ...
... Table 3 shows the characteristics of the studies that were selected for the systematic review regarding the study design, time of analysis, resistance exercise(s), prescription, weekly frequency, movement tempo, volume, and findings. Regarding the assessment of maximal strength development, 13 studies assessed dynamic strength using 1RM (56.5%) [11,[13][14][15]17,[21][22][23]29,44,[46][47][48] and another four studies assessed the isometric strength (17.4%) [26,38,39,45]. In addition, five studies simultaneously assessed dynamic strength using 1RM and isometric strength using a maximal voluntary isometric contraction (MVIC) (21.7%) [16,28,[41][42][43], and, finally, one study assessed isometric strength using maximal isometric voluntary torque (4.4%) [40]. ...
... Regarding maximal strength development measured by the 1RM test, 18 studies indicated a significant improvement between pre-and post-intervention using low-, moderate-, and high-load training protocols [11,[13][14][15][16][17][21][22][23]26,28,29,41,43,44,[46][47][48]. However, when a t-test for independent samples or ANOVA were used to compare differences between groups, most studies found that the moderate-and high-load groups significantly improved their 1RM compared to the low-load group [11,17,22,28,29,[41][42][43]46,48], although eight studies did not observe differences between these groups [13][14][15][16]21,23,26,44]. ...
The load in resistance training is considered to be a critical variable for neuromuscular adaptations. Therefore, it is important to assess the effects of applying different loads on the development of maximal strength and muscular hypertrophy. The aim of this study was to systematically review the literature and compare the effects of resistance training that was performed with low loads versus moderate and high loads in untrained and trained healthy adult males on the development of maximal strength and muscle hypertrophy during randomized experimental designs. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (2021) were followed with the eligibility criteria defined according to participants, interventions, comparators, outcomes, and study design (PICOS): (P) healthy males between 18 and 40 years old, (I) interventions performed with low loads, (C) interventions performed with moderate or high loads, (O) development of maximal strength and muscle hypertrophy, and (S) randomized experimental studies with between-or within-subject parallel designs. The literature search strategy was performed in three electronic databases (Embase, PubMed, and Web of Science) on 22 August 2021. Results: Twenty-three studies with a total of 563 participants (80.6% untrained and 19.4% trained) were selected. The studies included both relative and absolute loads. All studies were classified as being moderate-to-high methodological quality, although only two studies had a score higher than six points. The main findings indicated that the load magnitude that was used during resistance training influenced the dynamic strength and isometric strength gains. In general, comparisons between the groups (i.e., low, moderate, and high loads) showed higher gains in 1RM and maximal voluntary isometric contraction when moderate and high loads were used. In contrast, regarding muscle hypertrophy, most studies showed that when resistance training was performed to muscle failure, the load used had less influence on muscle hypertrophy. The current literature shows that gains in maximal strength are more pronounced with high and moderate loads compared to low loads in healthy adult male populations. However, for muscle hypertrophy, studies indicate that a wide spectrum of loads (i.e., 30 to 90% 1RM) may be used for healthy adult male populations. Citation: Lacio, M.; Vieira, J.G.; Trybulski, R.; Campos, Y.; Santana, D.; Filho, J.E.; Novaes, J.; Vianna, J.; Wilk, M. Effects of Resistance Training
... Therefore, the body mass-based RT used in the present study is included in the low-load resistance exercise, which induces muscle hypertrophy and slightly affects muscular strength in healthy young and middle-aged individuals consistent with Schoenfeld et al. (2017). Furthermore, previous studies reported a potential fibre type-specific loading zone effect, with higher loads showing a greater increase in type II muscle fibre CSA and lower loads showing a greater increase in type I muscle fibre growth (Netreba et al., 2013). Considering our results together with the previous study result (Netreba et al., 2013), the body mass-based RT might mainly relate to type I muscle fibre hypertrophy. ...
... Furthermore, previous studies reported a potential fibre type-specific loading zone effect, with higher loads showing a greater increase in type II muscle fibre CSA and lower loads showing a greater increase in type I muscle fibre growth (Netreba et al., 2013). Considering our results together with the previous study result (Netreba et al., 2013), the body mass-based RT might mainly relate to type I muscle fibre hypertrophy. However, the effect of body massbased RT on muscle fibre CSA has not been reported and needs further study. ...
New findings:
What is the central question of this study? How do free weight resistance training (RT) and body mass-based RT for 8 weeks compare for isometric muscular strength, muscle size and intramuscular fat (IMF) content in the quadriceps femoris? What is the main finding and its importance? Free weight and body mass-based RTs could induce muscle hypertrophy; however, decreased IMF content was observed following the body mass-based RT alone.
Abstract:
The objective of this study was to investigate the effects of free weight and body mass-based resistance training (RT) on muscle size and thigh intramuscular fat (IMF) in young and middle-aged individuals. Healthy individuals (aged 30-64 years) were assigned to either a free weight RT group (n = 21) or a body mass-based RT group (n = 16). Both groups performed whole-body resistance exercise twice a week for 8 weeks. Free weight resistance exercises (squats, bench press, deadlift, dumbbell rows and back range) involved 70% one repetition maximum, with three sets of 8-12 repetitions per exercise. The nine body mass-based resistance exercises (leg raise, squats, rear raise, overhead shoulder mobility exercise, rowing, dips, lunge, single-leg Romanian deadlifts and push-ups) included the maximum possible repetitions per session, which were performed in one or two sets. Mid-thigh magnetic resonance images using the two-point Dixon method were taken pre- and post-training. The muscle cross-sectional area (CSA) and IMF content in the quadriceps femoris were measured from the images. Both the groups showed significantly increased muscle CSA post-training (free weight RT group, P = 0.001; body mass-based RT group, P = 0.002). IMF content in the body mass-based RT group significantly decreased (P = 0.036) but did not significantly change in the free weight RT group (P = 0.076). These results suggest that the free weight and body mass-based RTs could induce muscle hypertrophy; however, in healthy young and middle-aged individuals, decreased IMF content was induced following the body mass-based RT alone.
... Several studies have investigated the influence of lower load, higher volume resistance training on fiber type hypertrophy with conflicting findings. While research [29,30] has suggested that the greater metabolic stress associated with lower load training may induce greater type I fiber hypertrophy, research by Morton et al. [5] and Mitchell et al. [4] in trained and untrained participants, respectively, showed no differences when higher or lower loads are completed to concentric failure. Moreover, research indicates similar hypertrophy between lower and higher load training in the soleus (a type I dominant muscle) and the gastrocnemii (a mixed fiber muscle) [31]. ...
Resistance training is a method of enhancing strength, gait speed, mobility, and health. However, the external load required to induce these benefits is a contentious issue. A growing body of evidence suggests that when lower load resistance training [i.e., loads < 50% of one-repetition maximum (1RM)] is completed within close proximity to concentric failure, it can serve as an effective alternative to traditional higher load (i.e., loads > 70% of 1RM) training and in many cases can promote similar or even superior physiological adaptations. Such findings are important given that confidence with external loads and access to training facilities and equipment are commonly cited barriers to regular resistance training. Here, we review some of the mechanisms and physiological changes in response to lower load resistance training. We also consider the evidence for applying lower loads for those at risk of cardiovascular and metabolic diseases and those with reduced mobility. Finally, we provide practical recommendations, specifically that to maximize the benefits of lower load resistance training, high levels of effort and training in close proximity to concentric failure are required. Additionally, using lower loads 2–3 times per week with 3–4 sets per exercise, and loads no lower than 30% of 1RM can enhance muscle hypertrophy and strength adaptations. Consequently, implementing lower load resistance training can be a beneficial and viable resistance training method for a wide range of fitness- and health-related goals.
... From a mechanistic standpoint, training to failure has been shown to create greater metabolic perturbations that could relate to greater training induced adaptations in HIEE [66,78,79]. Furthermore, reviews [32,62] and several longitudinal studies suggest that it is possible that slow-twitch Type I muscle fibers are better targeted and relatively developed to a greater extent with higher repetitions and training to failure [22,75,[80][81][82], this may be particularly true when slower movement speeds are used [83,84]. Stronger Type I fibers and a larger Type I CSA enhancement could lead to greater endurance. ...
Specificity has two major components: A strength-endurance continuum (S-EC) and adherence to principles of Dynamic Correspondence. Available evidence indicates the existence of the S-EC continuum from two aspects. Indeed, the S-EC exists, particularly if work is equated as a high load low repetition scheme at one end (strength stimulus) and high volume (HIEE stimulus) at the other. Furthermore, some evidence also indicates that the continuum as a repetition paradigm with high-load, low repetition at one end (strength stimulus) and a high repetition, low load at the other end. The second paradigm is most apparent under three conditions: (1) ecological validity—in the real world, work is not equated, (2) use of absolute loads in testing and (3) a substantial difference in the repetitions used in training (for example 2–5 repetitions versus ≥10 repetitions). Additionally, adherence to the principles and criteria of dynamic correspondence allows for greater “transfer of training” to performance measures. Typically, and logically, in order to optimize transfer, training athletes requires a reasonable development of capacities (i.e., structure, metabolism, neural aspects, etc.) before more specific training takes place
... Recent findings suggest that preferential hypertrophy for a specific fiber depends also on range of loading zones. High-load RT (>60% of 1RM) primarily increases cross-sectional area of type II muscle fibers, while type I fibers are increased with low-load RT (<60% of 1RM), but momentary muscular failure is needed (Vinogradova et al. 2013;Netreba et al. 2013). ...
Strength training, also known as weight or resistance training (RT), has become one of the most popular forms of exercise, not only for sport performance but also for improving health-related fitness. A wide variety of physiological adaptations achieved through RT have been documented in the short, medium, and long term. These improvements include changes in body composition, muscle hypertrophy, strength, power and motor performance; as well as other health benefits such as changes in blood pressure, insulin sensitivity, lipid profile, endocrine system, and better performance in daily life activities, among others. This chapter will cover the basic physiological adaptations of RT discussing neurological, musculoskeletal, cardiorespiratory, and endocrine responses and adaptations according to current scientific literature. These physiological concepts will be applied in following chapters in which specific methods and technologies for RT are presented.
... Research on the effect of low-load and high-load resistance training on the hypertrophic response of ST and FT fibers is still indecisive (Grgic & Schoenfeld, 2018). Some evidence indicates that low-load resistance training, may induce a greater hypertrophic response in ST muscle fibers compared to high-load resistance training, which may induce preferential growth of FT muscle fibers (Fisher et al., 2011;Mitchell et al., 2012;Netreba et al., 2013;Ogborn & Schoenfeld, 2014;Vinogradova et al., 2013). Likewise, a genetic-based algorithm, differentiating either endurance or power athletes and individualizing training with either lowor high-intensity resistance training, indicated that matching the individual's genotype with the appropriate training modality leads to more effective resistance training (N. ...
The human skeletal muscle consists of two major cell types, slow-twitch fibers (also called type I fibers) and fast-twitch fibers (or type II fibers). These fibers have distinct characteristics, as fast-twitch fibers are able to generate a large amount of power at high shortening velocities, while slow-twitch fibers have a better energy efficiency, a higher resistance to fatigue and a more robust structural integrity. On average, most humans will dispose of a 50% slow-twitch and a 50% fast-twitch distribution. However a big heterogeneity exists, what results in people with predominantly slow or fast muscle fibers. The typology of a person is mostly genetically determined and is present across most muscles of the body. Taken together, the fact that muscle fibers have distinct characteristics and that muscle typologies range over the whole continuum from predominantly slow to fast in human, will have important implications for sports performance. Nevertheless, these typologies are currently not used in the daily coaching practice. This is probably due to the invasiveness of the current ‘gold’ standard to measure the muscle typology: a muscle biopsy, which is a labor intensive method and harbors a low generalizability. In 2011, our group introduced a non-invasive way to estimate the muscle fiber type composition through the measurement of carnosine – a metabolite which is abundantly available in fast-twitch fibers – using proton magnetic resonance spectroscopy (1H-MRS). The non-invasiveness of this technique enables the use in both the sports practice and science, and renews the interest of the muscle typology in sports. In the first study, the 1H-MRS method to determine the muscle typology was further optimized with the ultimate goal to make it applicable on various scanner systems of multiple vendors. 1H-MRS was found to be a reliable method to quantify carnosine in the muscle. Furthermore, best practices were proposed to prevent often encountered methodological problems and step by step guidelines were developed to allow broader utilization of this technique. Secondly, we investigated if pre-puberty carnosine measurements could give insights in the post-puberty carnosine concentrations, which would allow application of this technique in early specialization sports (study 2). Carnosine was shown to be a trackable metabolite through the disruptive puberty period (R2=0.249-0.670), which confirms the potential of the current technique to scan both future talents and elite athletes. Next to the methodological optimization, the relevance of the muscle typology for talent identification was examined. Before the start of the thesis, the construct validity of our method was already confirmed in athletics, in which clear differences were determined in the muscle typology of either sprint or endurance disciplines. Despite the fact that a comparable distribution of the muscle typologies could be expected in other cyclic sports such as cycling and swimming, this was not yet investigated in elite athletes. Therefore, study 3 established the muscle typologies of 80 world-class cyclists. Clear differences were found in the muscle typology between cycling events. Keirin, bicycle motocross racing (BMX), sprint and 500 m to 1 km time trial cyclists can be considered as fast typology athletes. Time trial, points race, scratch, and omnium consist of intermediate typology athletes, while most individual pursuit, single-stage, cyclo-cross, mountain bike, and multistage cyclists have a slow typology. Nevertheless, this distribution was not present in 73 elite swimmers (study 4), as no clear differences in the muscle typology were detected between short and long distance swimming events in the different strokes. However, there was some evidence to suggest that truly world-class sprint swimmers had a faster muscle fiber type composition when compared to elite swimmers competing at the international level. Moreover, breaststroke swimmers were identified to have a faster muscle typology in comparison to the either freestyle, backstroke or butterfly swimmers. Elite soccer players (n=118) were found to have an on average intermediate typology, which matches with the intermittent nature of this sport (study 6). In contrary to our hypothesis, no differences in the muscle typology were detected between different positions (keeper, defender, midfielder and striker). A big heterogeneity was established over all positions, indicating that the muscle typology is not of major importance for talent identification in soccer. To determine the influence of the muscle typology on individualized training and recovery cycles, we investigated if fatigue and recovery were different when both slow and fast typology subjects were exposed to the same high-intensity training (study 5). Fatigue during three Wingate tests, determined by the power drop, was 20% higher in fast typology athletes. Even though the same work was done during these Wingate tests, also the recovery from these Wingate tests was found to be 15 times slower in fast typology athletes (20 min in slow typology vs. longer than 5 h in fast typology). If a training plan would be composed with a minimum of recovery in between the training sessions, recovery might be insufficient for fast typology athletes, possibly rendering them with a higher risk for muscle strains. In study 6, we studied if the muscle typology is a risk factor for muscle strains in elite soccer players. We discovered that fast typology soccer players had a 5.3 times higher chance to get a hamstring injury, when compared to slow typology soccer players during a prospective longitudinal follow-up study over three seasons. Next to a higher accumulation of fatigue, a higher vulnerability in fast typology players could be expected due to the lower structural integrity in fast fibers. Bringing together, the muscle typology is an important characteristic, which could be non-invasively monitored using 1H-MRS. This technique could help athletes to make a scientific based decision on their ideal discipline during talent orientation. Moreover, it could help coaches tailoring training to enlarge the athletes’ muscle potential and to prevent fatigue accumulation. This endeavor might partly prevent fast typology athletes to be at a higher risk for strain injuries. Consequently, we believe that measuring the muscle fiber typology of athletes should be considered as a valuable procedure to help athletes to fully develop their potential based on the smart use of muscle profiling.
... Although training to failure, as a result of fatigue, can recruit high threshold MU's, recruitment seems to be incomplete and selective (110,132). Training to failure, particularly with higher repetitions, tends to select Type I MU and heavier loading and ballistic movements targeting type II MU (24,57,152,153,229). In addition, evidence indicates that endurance training can interfere with strength training adaptations (62,236). ...
Periodization can be defined as a logical sequential, phasic method of manipulating fitness and recovery
phases to increase the potential for achieving specific performance goals while minimizing the potential for nonfunctional overreaching,
overtraining, and injury. Periodization deals with the micromanagement of timelines and fitness phases and is cyclic in
nature. On the other hand, programming deals with the micromanagement of the training process and deals with exercise selection,
volume, intensity, etc. Evidence indicates that a periodized training process coupled with appropriate programming can produce
superior athletic enhancement compared with nonperiodized process. There are 2 models of periodization, traditional and block.
Traditional can take different forms (i.e., reverse). Block periodization has 2 subtypes, single goal or factor (individual sports) and
multiple goals or factors (team sports). Both models have strengths and weaknesses but can be “tailored” through creative
programming to produce excellent results for specific sports.
... Thus, it is likely that these SM fibers display less upregulation of vasodilation mediated by endothelial factors, as well as an elevated α-adrenergic-mediated vasoconstriction, compared to type I fibers. Previous data suggested that obese (Krotkiewski et al., 1990), first-degree relatives (Nyholm et al., 1997), and T2D (Mårin et al., 1994) individuals might have a higher proportion of type II muscle fibers and second, usually hypertrophy-driven RT exercise has been hypothesized to mostly target type II muscle fibers (Folland and Williams, 2007;Netreba et al., 2013;Grgic and Schoenfeld, 2018). Admittedly, one could hypothesize that targeting SM hypertrophy might not be ideal in order to improve SM mechanisms of IS. ...
Skeletal muscle (SM) tissue has been repetitively shown to play a major role in whole-body glucose homeostasis and overall metabolic health. Hence, SM hypertrophy through resistance training (RT) has been suggested to be favorable to glucose homeostasis in different populations, from young healthy to type 2 diabetic (T2D) individuals. While RT has been shown to contribute to improved metabolic health, including insulin sensitivity surrogates, in multiple studies, a universal understanding of a mechanistic explanation is currently lacking. Furthermore, exercised-improved glucose homeostasis and quantitative changes of SM mass have been hypothesized to be concurrent but not necessarily causally associated. With a straightforward focus on exercise interventions, this narrative review aims to highlight the current level of evidence of the impact of SM hypertrophy on glucose homeostasis, as well various mechanisms that are likely to explain those effects. These mechanistic insights could provide a strengthened rationale for future research assessing alternative RT strategies to the current classical modalities, such as low-load, high repetition RT or high-volume circuit-style RT, in metabolically impaired populations.
Considerable inter-individual heterogeneity exists in the muscular adaptations to resistance training. It has been proposed that fast-twitch fibers are more sensitive to hypertrophic stimuli and thus that variation in muscle fiber type composition is a contributing factor to the magnitude of training response. This study investigated if the inter-individual variability in resistance training adaptations is determined by muscle typology and if the most appropriate weekly training frequency depends on
muscle typology. In strength-training novices, 11 slow (ST) and 10 fast typology (FT) individuals were selected by measuring muscle carnosine with proton magnetic resonance spectroscopy. Participants trained both upper arm and leg muscles to failure at 60% 1RM for 10 weeks, whereby one arm and leg trained 3x/week, the contralateral arm and leg 2x/week. Muscle volume (MRI-based 3D
segmentation), maximal dynamic strength (one-repetition maximum, 1RM) and fiber-type specific cross-sectional area (vastus lateralis biopsies) were evaluated. The training response for total muscle volume (+3 to +14%), fiber size (-19 to +22%) and strength (+17 to +47%) showed considerable interindividual variability, but these could not be attributed to differences in muscle typology. However, ST individuals performed a significantly higher training volume to gain these similar adaptations as
FT individuals. The limb that trained 3x/week had generally more pronounced hypertrophy than the limb that trained 2x/week, and there was no interaction with muscle typology. In conclusion, muscle typology cannot explain the high variability in resistance training adaptations when training is performed to failure at 60% of 1RM.
Hypertrophy can be operationally defined as an increase in the axial cross-sectional area of a muscle fiber or whole muscle, and is due to increases in the size of pre-existing muscle fibers. Hypertrophy is a desired outcome in many sports. For some athletes, muscular bulk and, conceivably, the accompanying increase in strength/power, are desirable attributes for optimal performance. Moreover, bodybuilders and other physique athletes are judged in part on their muscular size, with placings predicated on the overall magnitude of lean mass. In some cases, even relatively small improvements in hypertrophy might be the difference between winning and losing in competition for these athletes. This position stand of leading experts in the field synthesizes the current body of research to provide guidelines for maximizing skeletal muscle hypertrophy in an athletic population. The recommendations represent a consensus of a consortium of experts in the field, based on the best available current evidence. Specific sections of the paper are devoted to elucidating the constructs of hypertrophy, reconciliation of acute vs long-term evidence, and the relationship between strength and hypertrophy to provide context to our recommendations.
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