Ragazzi, mi rivolgo soprattutto agli appassionati delle ricerche scientifiche, segue una nuovissima ricerca della Sports Med.
Come al solito sono graditi i commenti!
Sports Med. 2007;37(3):225-64.
The influence of frequency, intensity, volume and mode of strength training on whole
muscle cross-sectional area in humans.
I thought I'd summarize this comprehensive paper both for my own benefit and for those who
want the highlights. I've restricted my summary to the parts of the paper that talk about
your typical "dynamic external resistance" training. The gist of the paper is that while
we do know what works for hypertrophy (pretty much everything, to an extent), we really
don't know what's optimal, especially in trained individuals and in the long run. Dan also
posted some excerpts on his forum: http://hypertrophy-research.com/phpB...opic.php?t=213
Results
No relationship could be found between frequency of training and the increase per day in
muscle cross sectional area. When the intensity was plotted against the rate of increase,
a weak tendency was found for the rate to increase with increasing intensity. The highest
rates of increase tended to occur around 75% of 1RM. When volume was plotted against the
rate of increase, greater gains in muscle mass were seen initially with increasing volume
while there were diminishing returns as the volume increased further. The highest rates of
increase tended to occur with 30-60 repetitions per session.
Discussion
Frequency: For hypertrophy, studies suggest that training two or three times per week is
superior to training one time per week, even when volume is equal. However, there doesn't
appear to be a benefit of three sessions per week over two. "Although some interesting
trends can be discerned from the data... there is clearly a need for further research on
training frequency in both highly-trained and less-trained subjects."
Intensity: "The studies reviewed in this article show that there is a remarkably wide
range of intensities that may produce hypertrophy. Still, there seems to be some
relationship between the load (or torque) and the rate of increase in CSA." This is not
linear, but seemed to peak around 75%. "Thus, the results of this review support the
typical recommendations with intensity levels of 70–85% of maximum when training for
muscle hypertrophy, but also show that marked hypertrophy is possible at both higher and
lower loads."
Volume: "Overall, moderate volumes (≈30–60 repetitions per session for DER training)
appear to yield the largest responses." An exception to this is with very high loads (90%
1RM or 120% to 230% 1RM with eccentrics) where high rates of growth have been shown with
volumes as low as 12-14 repetitions per session. To date, relatively few studies have
directly compared the effects of different volumes of work on the hypertrophic response as
measured by scanning methodology." The paucity of data clearly warrants further research.
Mode of Training and Type of Muscle Action: You often hear statements like "eccentric
training produces the greatest muscle hypertrophy". "This review demonstrates that given
sufficient frequency, intensity and duration of work, all three types of muscle actions
can induce significant hypertrophy at impressive rates and that at present, there is
insufficient evidence for the superiority of any mode and/or type of muscle action over
other modes and types of training in this regard." In fact, the data suggest that pure
eccentric training is inferior to both concentric and eccentric+concentric training,
though this is still a subject of debate rather than a scientific certainty.
Rest Periods and the Role of Fatigue: "Upon closer examination, it appears that when
maximal or near-maximal efforts are used, it is advantageous to use long periods of rest.
This is logical in light of the well known detrimental effects of fatigue on force
production and electrical activity in the working muscle. If high levels of force and
maximum recruitment of motor units are important factors in stimulating muscle
hypertrophy, it makes sense to use generous rest periods between sets and repetitions of
near-maximal to maximal efforts... On the other hand, when using submaximal resistance,
the size principle dictates that motor unit recruitment and firing rates are probably far
from maximal until the muscle is near fatigue or unless the repetitions are performed with
the intention to execute the movement very quickly."
Interactions Between Frequency, Intensity, Volume and Mode: "Based on the available
evidence, we suggest that the time-tension integral is a more important parameter than the
mechanical work output (force × distance)... Overall, we feel that the trends observed in
this review are consistent with the model for training-overtraining continuum proposed by
Fry,[186] where the optimal training volume and also the volume threshold for overtraining
decreases with increasing intensity... Regarding training for hypertrophy in already
highly-trained individuals, there is at present insufficient data to suggest any trends in
the dose-response curves for the training variables."
Eccentrics: "Taken together, the results of these studies support the common
recommendation of using somewhat lower frequencies and volumes for high-force eccentric
exercise than for conventional resistance training..."
Order of endurance/strength training: "It has been suggested that strength training should
be performed first, in order not to compromise the quality of the strength-training
session.[194] However, this order may not necessarily be the best choice for inducing
increases in muscle mass. Deakin[195] investigated the impact of the order of exercise in
combined strength and endurance training and reported that gene expression associated with
muscle hypertrophy responded more strongly when cycling was performed before strength
training, instead of vice versa. Interestingly, in the study of Sale et al.,[111]
performing cycling first seemed to induce the greatest increase in muscle area. Still,
because the lack of studies investigating the effects of the order of exercise in
concurrent training on hypertrophy, no firm conclusions can be drawn on this issue."
Time Course of Muscle Hypertrophy: "Until recently, the prevailing opinion has been that
neural adaptations play the dominant role during the first 6–7 weeks of training, during
which hypertrophy is usually minor." However, several investigations
[13,27,54,87,105,118,128] have demonstrated significant hypertrophy at the whole muscle
level after short periods of training (3–5 weeks). "Thus, there now plenty of evidence
that significant hypertrophy can take place early on given proper frequency, intensity and
volume of training," even prior to changes in muscle CSA. "As argued by Phillips,[198] the
idea that early gains in strength are due exclusively to neural adaptations seems
doubtful... In some strength-training studies, the increase in muscle volume is delayed,
while in others, the rate of growth is rapid. We speculate that less-damaging training
modes may allow the hypertrophy response to start earlier. Regimens that include eccentric
muscle actions, especially those involving maximal effort, appear to require a careful
initiation and progression of training to avoid muscle damage and muscle protein breakdown
[excessive apoptosis and proteolysis]."
The Stimulus for Muscle Hypertrophy in Strength Training: "Two studies by Martineau and
Gardiner[216,217] have provided insight into how different levels of force and different
durations of tension may affect hypertrophic signaling in skeletal muscle... they remarked
that both peak tension and time-tension integral must be included in the modeling of the
mechanical stimulus response of skeletal muscle... Based on the data reviewed in this
paper, we speculate that hypertrophic signalling in human skeletal muscle is very
sensitive to the magnitude of tension developed in the muscle. Hence, for very short
durations of work, the increase in muscle size will be greater for maximal-eccentric
exercise than for maximal-concentric exercise of similar durations... The response is
presumably also dependent on the total duration of work and increases initially with
greater durations. Thus, both short durations of maximal eccentric exercise and somewhat
longer durations of concentric, isometric and conventional dynamic resistance exercise can
result in impressive increases in muscle volume. However, especially with maximal
eccentric exercise, damage also seems to come into play as the duration of work increases
even further and the acute and/or cumulative damage may eventually overpower the
hypertrophic process."
Training Implications and Recommendations: For your typical "dynamic external resistance",
recommendations are given for "Moderate load slow-speed training", "Conventional
hypertrophy training", and "Eccentric (ecc) overload training". These three modes are
denoted as suitable for beginners, novice-well trained, and advanced-elite, respectively.
For the "Conventional hypertrophy training" for the novice to the well trained, they
recommend an 8-10RM load (75-80% 1RM), with 8-10 reps to failure or near failure, 1-3 sets
per exercise, progression from 1–2 to 3–6 sets total per muscle group, moderate velocity
(1-2 seconds for each CON and ECC), 60-180 seconds rest between sets, and 2-3 sessions per
muscle group per week.
Conclusions: "This review demonstrates that several modes of training and all three types
of muscle actions can induce hypertrophy at impressive rates and that, at present, there
is insufficient evidence for the superiority of any mode and/or type of muscle action over
other modes and types of training. That said, it appears that exercise with a
maximal-eccentric component can induce increases in muscle mass with shorter durations of
work than other modes. Some evidence suggests that the training frequency has a large
impact on the rate of gain in muscle volume for shorter periods of training. Because
longer studies using relatively high frequencies are lacking, it cannot be excluded that
stagnation or even overtraining would occur in the long term. Regarding intensity,
moderately heavy loads seem to elicit the greatest gains for most categories of training,
although examples of very high rates were noted at both very low and very high intensities
when the sets were performed with maximum effort or taken to muscular failure. Thus,
achieving recruitment of the greatest number of muscle fibres possible and exposing them
to the exercise stimulus may be as important as the training load per se. For the total
volume or duration of activity, the results suggest a dose-response curve characterised by
an increase in the rate of growth in the initial part of the curve, which is followed by
the region of peak rate of increase, which in turn is followed by a plateau or even a
decline. It is recognised that the conclusions drawn in this paper mainly concern
relatively short-term training in previously untrained subjects and that in highly trained
subjects or for training studies extending for several months, the dose-response trends
and the hypertrophic effects of different modes and types of strength training may be very
different. The same may well be true for other populations, such as elderly and injured
individuals."
Come al solito sono graditi i commenti!
Sports Med. 2007;37(3):225-64.
The influence of frequency, intensity, volume and mode of strength training on whole
muscle cross-sectional area in humans.
I thought I'd summarize this comprehensive paper both for my own benefit and for those who
want the highlights. I've restricted my summary to the parts of the paper that talk about
your typical "dynamic external resistance" training. The gist of the paper is that while
we do know what works for hypertrophy (pretty much everything, to an extent), we really
don't know what's optimal, especially in trained individuals and in the long run. Dan also
posted some excerpts on his forum: http://hypertrophy-research.com/phpB...opic.php?t=213
Results
No relationship could be found between frequency of training and the increase per day in
muscle cross sectional area. When the intensity was plotted against the rate of increase,
a weak tendency was found for the rate to increase with increasing intensity. The highest
rates of increase tended to occur around 75% of 1RM. When volume was plotted against the
rate of increase, greater gains in muscle mass were seen initially with increasing volume
while there were diminishing returns as the volume increased further. The highest rates of
increase tended to occur with 30-60 repetitions per session.
Discussion
Frequency: For hypertrophy, studies suggest that training two or three times per week is
superior to training one time per week, even when volume is equal. However, there doesn't
appear to be a benefit of three sessions per week over two. "Although some interesting
trends can be discerned from the data... there is clearly a need for further research on
training frequency in both highly-trained and less-trained subjects."
Intensity: "The studies reviewed in this article show that there is a remarkably wide
range of intensities that may produce hypertrophy. Still, there seems to be some
relationship between the load (or torque) and the rate of increase in CSA." This is not
linear, but seemed to peak around 75%. "Thus, the results of this review support the
typical recommendations with intensity levels of 70–85% of maximum when training for
muscle hypertrophy, but also show that marked hypertrophy is possible at both higher and
lower loads."
Volume: "Overall, moderate volumes (≈30–60 repetitions per session for DER training)
appear to yield the largest responses." An exception to this is with very high loads (90%
1RM or 120% to 230% 1RM with eccentrics) where high rates of growth have been shown with
volumes as low as 12-14 repetitions per session. To date, relatively few studies have
directly compared the effects of different volumes of work on the hypertrophic response as
measured by scanning methodology." The paucity of data clearly warrants further research.
Mode of Training and Type of Muscle Action: You often hear statements like "eccentric
training produces the greatest muscle hypertrophy". "This review demonstrates that given
sufficient frequency, intensity and duration of work, all three types of muscle actions
can induce significant hypertrophy at impressive rates and that at present, there is
insufficient evidence for the superiority of any mode and/or type of muscle action over
other modes and types of training in this regard." In fact, the data suggest that pure
eccentric training is inferior to both concentric and eccentric+concentric training,
though this is still a subject of debate rather than a scientific certainty.
Rest Periods and the Role of Fatigue: "Upon closer examination, it appears that when
maximal or near-maximal efforts are used, it is advantageous to use long periods of rest.
This is logical in light of the well known detrimental effects of fatigue on force
production and electrical activity in the working muscle. If high levels of force and
maximum recruitment of motor units are important factors in stimulating muscle
hypertrophy, it makes sense to use generous rest periods between sets and repetitions of
near-maximal to maximal efforts... On the other hand, when using submaximal resistance,
the size principle dictates that motor unit recruitment and firing rates are probably far
from maximal until the muscle is near fatigue or unless the repetitions are performed with
the intention to execute the movement very quickly."
Interactions Between Frequency, Intensity, Volume and Mode: "Based on the available
evidence, we suggest that the time-tension integral is a more important parameter than the
mechanical work output (force × distance)... Overall, we feel that the trends observed in
this review are consistent with the model for training-overtraining continuum proposed by
Fry,[186] where the optimal training volume and also the volume threshold for overtraining
decreases with increasing intensity... Regarding training for hypertrophy in already
highly-trained individuals, there is at present insufficient data to suggest any trends in
the dose-response curves for the training variables."
Eccentrics: "Taken together, the results of these studies support the common
recommendation of using somewhat lower frequencies and volumes for high-force eccentric
exercise than for conventional resistance training..."
Order of endurance/strength training: "It has been suggested that strength training should
be performed first, in order not to compromise the quality of the strength-training
session.[194] However, this order may not necessarily be the best choice for inducing
increases in muscle mass. Deakin[195] investigated the impact of the order of exercise in
combined strength and endurance training and reported that gene expression associated with
muscle hypertrophy responded more strongly when cycling was performed before strength
training, instead of vice versa. Interestingly, in the study of Sale et al.,[111]
performing cycling first seemed to induce the greatest increase in muscle area. Still,
because the lack of studies investigating the effects of the order of exercise in
concurrent training on hypertrophy, no firm conclusions can be drawn on this issue."
Time Course of Muscle Hypertrophy: "Until recently, the prevailing opinion has been that
neural adaptations play the dominant role during the first 6–7 weeks of training, during
which hypertrophy is usually minor." However, several investigations
[13,27,54,87,105,118,128] have demonstrated significant hypertrophy at the whole muscle
level after short periods of training (3–5 weeks). "Thus, there now plenty of evidence
that significant hypertrophy can take place early on given proper frequency, intensity and
volume of training," even prior to changes in muscle CSA. "As argued by Phillips,[198] the
idea that early gains in strength are due exclusively to neural adaptations seems
doubtful... In some strength-training studies, the increase in muscle volume is delayed,
while in others, the rate of growth is rapid. We speculate that less-damaging training
modes may allow the hypertrophy response to start earlier. Regimens that include eccentric
muscle actions, especially those involving maximal effort, appear to require a careful
initiation and progression of training to avoid muscle damage and muscle protein breakdown
[excessive apoptosis and proteolysis]."
The Stimulus for Muscle Hypertrophy in Strength Training: "Two studies by Martineau and
Gardiner[216,217] have provided insight into how different levels of force and different
durations of tension may affect hypertrophic signaling in skeletal muscle... they remarked
that both peak tension and time-tension integral must be included in the modeling of the
mechanical stimulus response of skeletal muscle... Based on the data reviewed in this
paper, we speculate that hypertrophic signalling in human skeletal muscle is very
sensitive to the magnitude of tension developed in the muscle. Hence, for very short
durations of work, the increase in muscle size will be greater for maximal-eccentric
exercise than for maximal-concentric exercise of similar durations... The response is
presumably also dependent on the total duration of work and increases initially with
greater durations. Thus, both short durations of maximal eccentric exercise and somewhat
longer durations of concentric, isometric and conventional dynamic resistance exercise can
result in impressive increases in muscle volume. However, especially with maximal
eccentric exercise, damage also seems to come into play as the duration of work increases
even further and the acute and/or cumulative damage may eventually overpower the
hypertrophic process."
Training Implications and Recommendations: For your typical "dynamic external resistance",
recommendations are given for "Moderate load slow-speed training", "Conventional
hypertrophy training", and "Eccentric (ecc) overload training". These three modes are
denoted as suitable for beginners, novice-well trained, and advanced-elite, respectively.
For the "Conventional hypertrophy training" for the novice to the well trained, they
recommend an 8-10RM load (75-80% 1RM), with 8-10 reps to failure or near failure, 1-3 sets
per exercise, progression from 1–2 to 3–6 sets total per muscle group, moderate velocity
(1-2 seconds for each CON and ECC), 60-180 seconds rest between sets, and 2-3 sessions per
muscle group per week.
Conclusions: "This review demonstrates that several modes of training and all three types
of muscle actions can induce hypertrophy at impressive rates and that, at present, there
is insufficient evidence for the superiority of any mode and/or type of muscle action over
other modes and types of training. That said, it appears that exercise with a
maximal-eccentric component can induce increases in muscle mass with shorter durations of
work than other modes. Some evidence suggests that the training frequency has a large
impact on the rate of gain in muscle volume for shorter periods of training. Because
longer studies using relatively high frequencies are lacking, it cannot be excluded that
stagnation or even overtraining would occur in the long term. Regarding intensity,
moderately heavy loads seem to elicit the greatest gains for most categories of training,
although examples of very high rates were noted at both very low and very high intensities
when the sets were performed with maximum effort or taken to muscular failure. Thus,
achieving recruitment of the greatest number of muscle fibres possible and exposing them
to the exercise stimulus may be as important as the training load per se. For the total
volume or duration of activity, the results suggest a dose-response curve characterised by
an increase in the rate of growth in the initial part of the curve, which is followed by
the region of peak rate of increase, which in turn is followed by a plateau or even a
decline. It is recognised that the conclusions drawn in this paper mainly concern
relatively short-term training in previously untrained subjects and that in highly trained
subjects or for training studies extending for several months, the dose-response trends
and the hypertrophic effects of different modes and types of strength training may be very
different. The same may well be true for other populations, such as elderly and injured
individuals."
Tra l'altro, domanda che mi incuriosisce alquanto: è possibile ottenere una buona ipertrofia insieme ad una buona forza???
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