Special consideration was taken to account for the dependency created because each participant contributed observations in two of the four possible training conditions and at multiple time points.

ANOVA models were estimated using covariance pattern models. Two different error covariance structures were compared prior to hypothesis testing: compound symmetry and unstructured. Otherwise, main effects of time and condition were examined.

A one-factor analysis of variance ANOVA was used to detect differences across time for control muscle thickness. Results are presented as mean SE unless otherwise stated.

Changes in anterior and lateral muscle thickness separated by condition can be seen in Tables 1 , 2 , respectively. FIGURE 1. Anterior muscle thickness. FIGURE 2. Lateral muscle thickness. FIGURE 3.

Knee extension 1RM. Changes from pre-training to post-training knee extension 1RM one-repetition maximum for each condition. Letters indicate significant differences between conditions.

If conditions share the same letter they are not different from one another. There was a main effect of time for isometric strength Changes for dynamometry are depicted in Figure 4 and can be seen separated by condition in Table 3. FIGURE 4. Isometric and isokinetic torque. FIGURE 5. Knee extension endurance.

Changes from pre-training to post-training knee extension endurance repetitions for each condition. For all conditions, the muscle swelling response increased from training session 1 to session 9 [0.

FIGURE 6. Exercise-induced swelling response. The exercise-induced swelling response to session 1, session 9, and session Data presented as mean SE.

Letters next to condition labels indicate significant differences main effect of condition. Weekly exercise volume was calculated as the average number of repetitions completed over the two weekly training sessions, multiplied by the load lifted.

In general, volume increased in most successive weeks, for each condition, throughout the training protocol.

Both completed all repetitions for the remaining sessions Figure 7. All others reached volitional failure at some point during the protocol. FIGURE 7. Average training volume per session during each week of the training protocol. Data presented as mean values. This figure is a visual aid, and as such, no statistical comparisons are denoted.

The main findings of the current study were that 1RM changes favored the high-load condition, while isometric and isokinetic strength responded similarly across all conditions. The increase in muscle thickness from training seemed to be uniform across conditions.

We believe the changes in muscle thickness were due to muscle growth rather than edema as there was an exercise-induced swelling response at training sessions 1, 9, and 15, suggesting minimal swelling prior to exercise at each phase of training.

Training volume was greatest in non-restriction conditions and then decreased with increased pressure. When comparing strength outcomes to Holm et al. However, we diverge from Holm et al.

The responses in 1RM, favoring high-load over very low-load, were expected due to the practicing of a skill that more closely resembles this specific strength test Buckner et al. To illustrate, previous studies have found that changes in 1RM favor high-load training over low-loads Mitchell et al.

During the study by Holm et al. We found no effect of load or BFR on dynamometry measured strength changes while Holm et al. BFR has been previously shown to augment the isometric Shinohara et al. This suggests either a potential loading threshold, or a lack of practice with the test overall as we only performed dynamometry pre and post-training.

Future research should seek to compare the response to these conditions in clinical populations to determine the effect on muscle strength.

While the relative improvement in this study was low, the effect could be greater or more meaningful in those with limited physical function. Further if BFR reduces the workload while providing similar muscular improvements it could be an effective therapeutic tool. While Holm et al.

The mechanism causing this greater response to endurance may either be strictly physiological, psychophysiological, or both. BFR also augments angiogenic gene expression in response to acute low-load resistance exercise Larkin et al. In addition, psychophysiological adaptations may have also occurred.

For example, as greater BFR pressures i. The increased endurance from pre to post-training in all conditions is supported by the increased weekly volume during training which could reflect an increased work capacity.

Although the exact mechanism was not explored in the current study, it seems as though greater BFR pressure i. This finding could have positive implications for clinical and elderly populations as activities of daily living are often submaximal and repetitive; however, future research should examine if these improvements in knee extension endurance do indeed transfer to activities of daily living.

Our findings of similar improvements in muscle thickness across all sites, regardless of condition, differ from those of Holm et al.

We believe the discrepancies can be explained by exercising to volitional failure. While on average our participants exercised to volitional failure only 2 participants reached 90 repetitions for all four sets , Holm et al. Therefore, in the Holm et al. While it seems the data by Lixandrao et al.

We argue that, were exercise performed to volitional failure, the muscle growth may have been similar across conditions. In fact, multiple experimental studies have shown that when comparing low-loads with and without BFR Fahs et al.

Overall, the current data suggests that when exercising to volitional failure the increase in muscle size is neither load nor pressure dependent, supporting a recent meta-analysis resulting in a similar conclusion Lixandrão et al.

In contrast, Lasevicius et al. While these differences could be due to differing image analyses the authors used separate muscle thickness images to estimate cross-sectional area , the data from Lasevicius et al.

Regardless, their finding of a need to use greater loads to maximally stimulate muscle growth is not a consistent finding and more work should be done to reconcile these differences. As concerns exist regarding the ability to distinguish true muscle growth from muscle edema in the early phases of a training program Damas et al.

A previous investigation found a limit in the ability for exercise to induce muscle swelling by showing that a swollen muscle did not swell further when undergoing a second bout of exercise Buckner et al.

We found that the exercise-induced swelling response was present at each time-point and increased over the training protocol. The increase in the swelling response across time may have been due to the increase in exercise volume across the training protocol, or perhaps the increase in muscle size, which could theoretically hold a greater volume of fluid.

A previous study measuring acute exercise-induced changes in muscle thickness at the beginning and end of a training program, found a muscle swelling response at both time points Farup et al. We believe this generally only affected volume in the early sets as only 2 of 40 total participants eventually reached repetitions during training.

Although it was not required to reach volitional failure, and did not seem to augment the strength or muscle size response to very-low loads, BFR did reduce the amount of volume required to elicit adaptations in a pressure dependent manner.

This may be important for a variety of populations that wish to increase muscle size and endurance but wish to limit the amount of overall work whether it be due to injury, frailty, or a simple desire to limit joint stress.

Furthermore, while volume is thought to be an important training variable, the data herein suggests there may not be a dose-response relationship with respect to muscle growth, as all conditions increased muscle thickness similarly.

Thus, there is likely a point where additional volume is no longer augmenting muscle growth. Future research should investigate whether a minimum volume threshold to elicit adaptation exists and whether or not that threshold differs between trained and untrained individuals. Our study may have been limited by the design, requiring each participant to train unilaterally using two different conditions, potentially inducing a crossover effect between legs.

However, these issues are likely minimal as both limbs were trained MacInnis et al. Our statistical analysis also helped to account for any potential issues of dependency two conditions from each participant.

BFR was based upon a percentage of resting AOP measurement, rather than quantified blood flow, thus, no assumptions can be made about the actual percent reduction in blood flow caused by the different cuff inflation pressures. While the amount of work increased most weeks, the difference in 1RM changes between conditions might have been greater had loads been progressed, however, doing so could have posed a separate set of limitations.

However, rest periods used were in accordance with commonly used BFR and traditional high load protocols. Lastly, for a measure of reliability, we included a control muscle thickness site on an upper body muscle group that was not trained.

Including muscle thickness measures on the leg for a time matched non-exercise control group would have been a stronger design. An increase in strength was seen in the 1RM test following high-load training only and there were no differences in conditions for isometric or isokinetic measures suggesting that increases in isotonic strength are load dependent.

The current data also suggest that the application of a higher BFR pressure creates a unique stimulus compared to non-restriction conditions to increase endurance.

Muscle size did not depend on load, nor was it affected by the differences in volumes or restriction pressures. Given muscle size increases did not differ across conditions, despite differences in exercise volume, suggests a lack of a dose-response relationship.

Furthermore, the lack of strength increase in the very low-load conditions while similar increases in muscle size were found suggests a dissociation between the two. MJ, SB, JM, KM, SD, TA, ZB, and JL were involved with conceptualization, implementation, and data collection.

MJ, JB, and JL were involved with statistical analyses. MJ, SB, JM, KM, SD, TA, ZB, JB, and JL were involved with drafting and editing the manuscript.

This work was supported in part through grants provided by The Japanese Society of Wellness and Preventive Medicine as well as The School of Applied Sciences at The University of Mississippi.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Buckner, S. Differentiating swelling and hypertrophy through indirect assessment of muscle damage in untrained men following repeated bouts of resistance exercise. doi: PubMed Abstract CrossRef Full Text Google Scholar. Determining strength: a case for multiple methods of measurement.

Sports Med. Burd, N. Muscle time under tension during resistance exercise stimulates differential muscle protein sub-fractional synthetic responses in men.

Counts, B. Influence of relative blood flow restriction pressure on muscle activation and muscle adaptation. Muscle Nerve 53, — Damas, F. Early resistance training-induced increases in muscle cross-sectional area are concomitant with edema-induced muscle swelling.

Dankel, S. Perceptual and arterial occlusion responses to very low load blood flow restricted exercise performed to volitional failure.

Imaging doi: Training to fatigue: the answer for standardization when assessing muscle hypertrophy? Fahs, C. Muscular adaptations to fatiguing exercise with and without blood flow restriction.

Imaging 35, — Farup, J. Blood flow restricted and traditional resistance training performed to fatigue produce equal muscle hypertrophy. Sports 25, — Ferguson, R. The acute angiogenic signalling response to low-load resistance exercise with blood flow restriction.

Sport Sci. Ganesan, G. Effect of blood flow restriction on tissue oxygenation during knee extension. Sports Exerc. Holm, L. Changes in muscle size and MHC composition in response to resistance exercise with heavy and light loading intensity. Hunter, S. Sex differences in the fatigability of arm muscles depends on absolute force during isometric contractions.

PubMed Abstract Google Scholar. Jessee, M. The cardiovascular and perceptual response to very low load blood flow restricted exercise.

Kacin, A. Frequent low-load ischemic resistance exercise to failure enhances muscle oxygen delivery and endurance capacity. Sports 21, e—e Larkin, K. Blood flow restriction enhances post-resistance exercise angiogenic gene expression.

Lasevicius, T. Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy.

The neuromuscular system goes through a cycle when developing strength: Teach the brain to fire correct muscles to contract with a new movement, add resistance, recruit more muscle fibers to oppose the resistance, build strength and adapt to the resistance, increase the complexity or resistance, and repeat.

Complex strength training exercises involving the whole body demand greater muscle recruitment and more closely approximate the demands in each sport. For example, a deep squat will yield a greater gain for an athlete than a biceps curl because the squat requires coordination among the hamstrings, hips, glutes, quads, and core to complete the movement.

Additionally, performing strength exercises when the body is fatigued will teach the brain to recruit muscles when it normally does not. This adaptation is useful at the end of a race, game, or event when an athlete's strength normally begins to wane.

If athletes do not perform an exercise with sufficient resistance, velocity, or complexity, they might develop muscle memory for an improper movement pattern. Because practice solidifies muscle memory, athletes should pay attention to how they execute resistance training. More qualitatively, athletes should be getting through reps of a given exercise where the last couple reps are challenging.

As always, technique takes priority over increasing resistance. In order to reduce the risk of injury, it is important that athletes memorize the right technique before they start adding more resistance.

For each exercise, athletes need to move through the movement with sufficient velocity. Strength training with speed builds neural pathways and movement patterns that enhance performance. Athletes may need to decrease resistance to ensure they can move with enough velocity and the correct technique.

Whole body exercises more closely approximate the neuromuscular demand of movements in sports because they require coordination among several muscle groups to achieve the motion.

Functional movements like squats, lunges, and pushups demand complexity and teach the brain to fire all the muscles necessary, whereas isolated movements only fire one muscle group at a time.

Complex exercises are the most effective way for athletes to develop full body strength. Neural adaptations are happening all the time during strength training. The brain sends signals along motor pathways to tell muscles when, how quickly, and how powerfully to contract to produce movement.

Athletes should take advantage of muscle memory, and coaches should develop strength training programs that implement sufficient resistance, velocity, and complexity in order to maximize performance. To learn more about strength training check out this article about cyclic training and progressions and this article about sports periodization.

At Bridge, we are all athletes and coaches first. As athletes, our team has experienced everything from riding the pine on JV, to winning NCAA championships, to competing in the Olympic Games. As coaches, we have helped countless athletes reach their full potential, winning everything from age group section championships to Olympic Gold Medals.

This post is part of our Coaches Corner series with Taylor Rimmer. Taylor is NSCA-CPT, StrongFirst A recent study has discovered that a week supervised strength training program SSTP may result July 24, By BridgeAthletic.

Neural Adaptations and Strength Training.

Resistance training has been shown to reduce factors associated with coronary heart disease, diabetes and osteoporosis.

Further research is needed to elucidate the effects of resistance training on blood lipids, lipoproteins and blood pressure in hypertensives , and to ascertain what type of training programs may best alter these risk factors.

From this overview, there are some practical guidelines for the health fitness professional and personal trainer who wish to prescribe resistance training programs for health status improvement. They are as follows: 1. Develop programs that will utilize a greater amount of energy expenditure during the workouts.

Programs that utilize the larger muscle groups provide a structural basis for the preferred loading that is recommended for improvements in bone mass and mineral density.

This will also contribute to the caloric cost of the programs, helping to facilitate weight management goals. Use moderate intensity programs, with multiple sets of 8 to 12 repetitions Stone et al.

A frequency of 2 - 3 times a week of resistance training appears applicable and attainable. Programs designed to increase total workout volume total repetitions x weight are encouraged. As with any effective exercise prescription, individualize the program, with a carefully planned, progressive overload.

Be guarded in the use of isometric contractions and high-intensity load training due to the marked increase observed in diastolic and systolic blood pressure.

Incorporate a variety of exercises. In order to avoid the effects of overtraining, muscle soreness, and injury, a prescription of resistance training using a variety of exercises is prudent. With certain organic conditions, such as musculoskeletal conditions i.

Take the time to teach the correct performance techniques of the resistance exercises. In the methodology sections in a number of the studies, the researchers emphasized the importance of teaching the subjects safe and correct resistance training mechanics.

Be aware that the training demands of resistance training may be greater for novice, low-fitness level, and elder individuals, due to the unique physiological challenges of the activity, and the level of fitness of the individuals. Often times, the use of longer rest periods between sets may be beneficial to help these populations adapt to the training demands.

Multiple-joint exercises are more demanding than single-joint exercises, and thus suggest that the training frequency days per week may need to be provide adequate recovery up to 48 hrs for the clients, especially when just beginning a resistance training program.

Develop an effective dialogue with your students. In an attempt to keep the training regimen satisfactory for the study, some researchers mentioned the importance of communication with the subjects in order to sustain the investigation.

Effective communication is also consequential in developing and maintaining effective training programs for your students. References : Behm, D. Velocity specificity of resistance training. Sports Medicine, 15, Blumenthal, J. Failure of exercise to reduce blood pressure in patients with mild hypertension.

Journal of the American Medical Association, , Conroy, B. Bone, muscle and connective tissue adaptations to physical activity. Baechle Ed. Champaign: Human Kinetics. Adaptive responses of bone to physical activity.

Medicine Exercise Nutrition Health, 1, Fleck, S. Cardiovascular adaptations to resistance training. Medicine and Science in Sports and Exercise, 20 Suppl. Hagberg, J. Effect of weight training on blood pressure and hemodynamics in hypertensive adolescents.

Journal of Pediatrics, 19, Harris, K. Physiological response to circuit weight training in borderline hypertensive subjects. Medicine and Science in Sports and Exercise, 19, Hather, B. Influence of eccentric actions on skeletal muscle adaptations to resistance training. Acta Physiologica Scandinavia, , Hurley, B.

Does strength training improve health status. Strength and Conditioning, 16, Resistive training can reduce coronary risk factors without altering VO2max or percent body fat. An increase in motor unit synchronization will result in elevated levels of force development 6.

The final major neuromuscular adaptation to strength training is the decrease of co-activation from antagonist muscles 4, 6.

As agonist muscles try to move a limb in one direction, they are opposed by antagonist muscles, which are working to move the limb in the opposite direction 6.

Although co-activation of agonist and antagonist muscles increases the joint stability and stiffness 4 , it is responsible for a decrease in force development 4, 6.

Strength training reduces this co-activation 4, 6 and therefore an increase in force production is evident 4, 6. Effect of Strength Training on Anaerobic Performance.

To determine whether strength training has a positive effect, it is important to identify the key factors associated with anaerobic performance. I am emphasizing the ability to create a large amount of force and power over a short distance or period of time.

This review has confirmed that strength training will improve strength 3, 5, 12 and power 2, Improved strength and power are products of neuromuscular responses such as improved rate coding 4, 6 and the decreased co-activation of antagonist muscles 4, 6.

Strength training also results in muscle fibers shifting towards type IIA muscle fibers 1, 9, 14 , which can produce times the peak power of type I fibers 16 and increased CSA 1, 9, 10 , which has also been positively correlated with an increased strength and power In conclusion, if you want to improve your anaerobic performance, then strength training is one of the most effective tools you could take advantage of.

Strength training results in physiological adaptations to the body, which as discussed can be split into two subgroups; Muscle fiber responses and neuromuscular responses.

Based on the literature reviewed, there are some practical applications. If you are competing in a sport that relies on elevated anaerobic activity, then strength training will improve your overall athletic performance and reduce the risk of injury.

Andersen, J. Effects of strength training on muscle fiber types and size; consequences for athletes training for high-intensity sport.

Chtourou, H. The effect of strength training at the same time of the day on the diurnal fluctuations of muscular anaerobic performances. Journal of Stength and Conditioning Research, 26 1 , Comfort, P.

Are changes in maximal squat strength during preseason training reflected in changes in sprint performance in rugby league players? Journal of Stength and Conditioning Research, 26 3 , Duchateau, J. Training adaptations in the behavior of human motor units. Journal of Applied Physiology, , Fatouros, I.

Strength training and detraining effects on muscular strength, anaerobic power, and mobility of inactive older men are intensity dependent. British Journal of Sports Medicine, 39 10 , Gabriel, D. Neural adaptations to resistive exercise.

Sports Medicine, 36 2 , Ingle, L. Certainly with the advances in molecular biology and cell biology we understand a lot more about these molecular responses. So how do these signaling pathways impact ultimately on gene expression, messenger RNA expression, protein expression?

Various transcription factors MEF2, GLUT-4 enhancement factor, PGC-1 alpha, which is thought to play an important role in mitochondrial biogenesis, are all transcription factors that are been in implicated in the adaptive response of muscles to exercise.

More recently interest in small non-coding pieces of RNA called micro RNAs, which have been shown to influence the expression and transcription of genes and the expression of proteins.

So, here in graphical form and nicely summarized we can see various signals that are acting on a contracting muscle. Either in an endurance type prolonged exercise, high-intensity exercise but with dynamic exercise. Through two more resistance type exercises where the adaptations perhaps are more related to muscle mass or what we can refer to hypertrophy.

If we focus on some of the adaptations to endurance-type exercise, these are largely focused on increasing the oxidative capacity of the muscle. The mitochondria who are the oxidative powerhouse of the muscle cell. They increase their total volume in response to exercise and that has important metabolic consequences.

We see large increases in mitochondrial density and oxidative enzymes to response to endurance-type exercise. We also see an increase in capillary density and you can see in this slide here, the capillaries that circle muscle fibers and there are more of them after training and that facilitates the delivery of oxygen to the muscle and needs to occur in parallel with the increases in oxidative capacity within the muscle.

Question mark on fiber type changes? You see quite a profound transformation of the characteristics of skeletal muscles. In terms of the functional consequences, we see reduced reliance on carbohydrates, reduced lactate production and increased fat oxidation during exercise after endurance type training.

From a health perspective, endurance training also improves the action of insulin. In terms of specific adaptations, let me give you just one example. This is one of our research interests here at the University of Melbourne.

How does endurance training impact on the expression of the GLUT4 transport protein? You can see that the trained subjects had higher muscle oxidative capacity and higher levels of GLUT4 compared with the untrained subjects. When we asked these trained subjects to stop their regular training for 10 days and report back to the lab.

You can see that there was a reduction in their oxidative capacity and a reduction in their GLUT4 expression. So, cessation of training reduced or diminished some of these adaptive responses.

Whether that would take a longer period of detraining, or whether these athletes have some genetic characteristics, which endow them with slightly higher muscle oxidative capacity or GLUT4 again, is one of those questions we may ask later in the course.

If we look at the factors that regulate GLUT4 expression, and this seems like a complex slide. But it really reprises the thing in the very first slide about signals, enzymes that detect those signals and functional consequences.

So, in the case of GLUT4 expression, there are two main signals that are thought to be important.

There are mitogen-activated protein kinases that seem to play a role in growth adaptations. An important enzyme involved in protein synthesis known as mTOR. Certainly with the advances in molecular biology and cell biology we understand a lot more about these molecular responses. So how do these signaling pathways impact ultimately on gene expression, messenger RNA expression, protein expression?

Various transcription factors MEF2, GLUT-4 enhancement factor, PGC-1 alpha, which is thought to play an important role in mitochondrial biogenesis, are all transcription factors that are been in implicated in the adaptive response of muscles to exercise. More recently interest in small non-coding pieces of RNA called micro RNAs, which have been shown to influence the expression and transcription of genes and the expression of proteins.

So, here in graphical form and nicely summarized we can see various signals that are acting on a contracting muscle. Either in an endurance type prolonged exercise, high-intensity exercise but with dynamic exercise.

Through two more resistance type exercises where the adaptations perhaps are more related to muscle mass or what we can refer to hypertrophy. If we focus on some of the adaptations to endurance-type exercise, these are largely focused on increasing the oxidative capacity of the muscle.

The mitochondria who are the oxidative powerhouse of the muscle cell. They increase their total volume in response to exercise and that has important metabolic consequences. We see large increases in mitochondrial density and oxidative enzymes to response to endurance-type exercise.

We also see an increase in capillary density and you can see in this slide here, the capillaries that circle muscle fibers and there are more of them after training and that facilitates the delivery of oxygen to the muscle and needs to occur in parallel with the increases in oxidative capacity within the muscle.

Question mark on fiber type changes? You see quite a profound transformation of the characteristics of skeletal muscles.

In terms of the functional consequences, we see reduced reliance on carbohydrates, reduced lactate production and increased fat oxidation during exercise after endurance type training. From a health perspective, endurance training also improves the action of insulin.

In terms of specific adaptations, let me give you just one example. This is one of our research interests here at the University of Melbourne. How does endurance training impact on the expression of the GLUT4 transport protein?

You can see that the trained subjects had higher muscle oxidative capacity and higher levels of GLUT4 compared with the untrained subjects. When we asked these trained subjects to stop their regular training for 10 days and report back to the lab. You can see that there was a reduction in their oxidative capacity and a reduction in their GLUT4 expression.

So, cessation of training reduced or diminished some of these adaptive responses. Whether that would take a longer period of detraining, or whether these athletes have some genetic characteristics, which endow them with slightly higher muscle oxidative capacity or GLUT4 again, is one of those questions we may ask later in the course.

If we look at the factors that regulate GLUT4 expression, and this seems like a complex slide. References : Behm, D. Velocity specificity of resistance training.

Sports Medicine, 15, Blumenthal, J. Failure of exercise to reduce blood pressure in patients with mild hypertension. Journal of the American Medical Association, , Conroy, B.

Bone, muscle and connective tissue adaptations to physical activity. Baechle Ed. Champaign: Human Kinetics. Adaptive responses of bone to physical activity. Medicine Exercise Nutrition Health, 1, Fleck, S. Cardiovascular adaptations to resistance training.

Medicine and Science in Sports and Exercise, 20 Suppl. Hagberg, J. Effect of weight training on blood pressure and hemodynamics in hypertensive adolescents. Journal of Pediatrics, 19, Harris, K.

Physiological response to circuit weight training in borderline hypertensive subjects. Medicine and Science in Sports and Exercise, 19, Hather, B. Influence of eccentric actions on skeletal muscle adaptations to resistance training. Acta Physiologica Scandinavia, , Hurley, B.

Does strength training improve health status. Strength and Conditioning, 16, Resistive training can reduce coronary risk factors without altering VO2max or percent body fat. Medicine and Science in Sports and Exercise, 20, Kannel, W. Epidemiologic profile and risks of coronary heart disease.

American Journal of Cardiology, 52, Kokkinos, P. Strength training and lipoprotein-lipid profiles: A critical analysis and recommendations for further study. Sports Medicine, 9, Kraemer, W. General adaptations to resistance and endurance training programs.

Baechle Eds. Moritani, T. Neural factors versus hypertrophy in the time course of muscle strength gain. American Journal of Physiological Medicine, 58, Sale, D. Neural adaptation to resistance training. Smutok, M. Aerobic vs.

strength training for risk factor intervention in middle-aged men at high risk for coronary heart disease. Metabolism, 42, Staron, R. Skeletal muscle adaptations during the early phase of heavy-resistance training in men and women. Journal of Applied Physiology, 76, Strength and skeletal muscle adaptations in heavy-resistance trained women after detraining and retraining.

Contrary to popular belief, these two aspects of intramuscular coordination - recruitment and rate coding - play greater determinant roles than synchronization does in muscular force production.

Intermuscular coordination, on the other hand, is the capacity of the nervous system to coordinate the "rings" of the kinetic chain, thus making the gesture more efficient. With time, as the nervous system learns the gesture, fewer motor units get activated by the same weight, which leaves more motor units available for activation by higher weights see figure 2.

Therefore, to increase the weight lifted in a given exercise over the long term, intermuscular coordination training technique training is the key. Nevertheless, intermuscular coordination is very exercise specific, so its transfer to other exercises including sport-specific ones is very limited.

Even so, it remains the base for the athlete's general strength development. Over time, strength training for intermuscular coordination reduces the motor unit activation necessary to lift the same load, thus leaving more motor units available for higher loads.

Despite the fact that the hypertrophic response to training is immediate Ploutz, et al. These proteins, which represent the specific adaptive response to the imposed training, stabilize the achieved neural adaptations.

This is the way to read the famous study by Moritani and deVries see figure 2. Therefore, to increase strength over time, one must keep training the factors discussed here. This is particularly true of intermuscular coordination, which allows load increase in the midterm and the long term on the basis of ever-increasing system efficiency, as well as specific hypertrophy.

Neural and muscular adaptations to strength training over time, according to Moritani and deVries Adapted, by permission, from T. Moritani and H. deVries, , "Neural factors versus hypertrophy in the time course of muscle strength gain," American Journal of Physical Medicine 58 3 For years, Eastern European training methodologists and coaches have been using training intensity zones as brackets of 1RM to design and analyze strength training programs.

According to most of the strength training methodology literature, the best training zones to elicit maximum strength gains were zones 2 and 1 loads from 85 percent and up. In more recent years, the focus has shifted from zone 1 loads those over 90 percent to zone 3 loads those from 70 percent to 80 percent.

This shift has occurredon the basis of field experience of weightlifters except for the Bulgarian and Greek schools and their North American clones, who have used very high intensities very frequently and, not coincidentally, have had a sad story of positive doping tests , as well as Russian and Italian powerlifters.

That is, analysis of the best weightlifters' programs Roman and powerlifters has shown a concentration of training loads in zone 3. Again, identifying zone 3 as the most important zone for maximum strength development is a fundamental change because almost all classic literature about strength training has indicated that training loads for maximum strength development should be 85 percent of 1RM or higher.