Introduction:
Resistance training (RT) has been observed for many decades that it has positive effects on both health and fitness of the general population, fit individuals and athletes, as well as patients suffering from chronic diseases. One chronic adaptation that occurs during the implementation of a resistance training program is muscular hypertrophy.
In the implementation of these programmes (PAs), many parameters governing them are responsible for their successful outcome. The intensity (as a percentage of 1 maximum repetition 1RM), training volume, training frequency, intervals between sets, time under tension, inter set intervals, choice of exercises, rate of execution, but also techniques of execution (drop sets, supersets, giant sets, pre-exhaustion, peak contraction) influence the result. The percentage of 1 maximum repetition 1RM), the training volume, the frequency of training, the breaks between sets, time under tension, inter set intervals, choice of exercises, the rhythm of execution and the techniques of execution (drop sets, supersets, giant sets, pre-exhaustion, peak contraction) influence the result.

In this review we will deal with the weekly training volume, which is defined as the load times the number of repetitions in each set, times the number of sets per week, per muscle group.

Conclusions:
It appears that muscle hypertrophy is directly related to training volume. The greater the weekly training volume, the greater the hypertrophy. But this seems to happen up to a certain threshold. From that point onwards, hypertrophy plateaus and if the volume is increased even further, the hypertrophy becomes smaller and smaller. In other words, an inverted U, or Bell Curve as mentioned in Schoenfeld’s meta-analysis (12), is presented. This point cannot be precisely defined, and is probably different for different muscle groups. Most likely, thigh muscles respond better to higher training volume than other muscle groups (1,6) . Probably for most it is between 10-20 sets. Although the differences between groups in the studies were not statistically significant, a trend is nevertheless emerging that supports the above conclusion. It is possible that high volume can be used within a training period for relatively short durations, followed by a deload phase.

More research is needed to clearly elucidate the relationship between hypertrophy and resistance training volume and to define the range of optimal volume and perhaps for each muscle group individually.

The following is a list of studies, table and bibliography

In this review we will deal with the weekly training volume, which is determined by
as the load times the number of repetitions in each set, times the number of sets per week, per muscle group.

A review – meta-analysis by Brad J. Schoenfeld , Dan Ogbornb and James W. Krieger 2016 (12)
demonstrates a direct correlation with the addition of each additional set to the weekly volume and the increase in
muscle mass. They were categorized as low volume < 5 scs, medium volume 5-9 scs, high volume 10+.
Similar results were noted in reviews by Krieger,JW 2009(6) and Peterson MD, Sen A,
Gordon PM 2011(9).
Also, some studies Burd NA et al. 2010; Terzis G. Et al.2010 (3,13) presented the protein synthesis
in muscle and intramuscular anabolic pathways to respond positively to the increase in training volume.
Many researchers and practitioners believe that there is an inverted U or Bell Curve relationship between
the total weekly PA volume and the desired physiological responses. That is, when the
training volume reaches a certain threshold, then a plateau occurs and from that point and
then its further increase leads to a decline in desirable adaptations Schoenfeld et al. (12).

In the study by Brad J. Schoenfeld et al. 2019 (13) although there was no direct training stimulus for expansive
and elbow flexors, hypertrophy was observed increasing with increasing training volume. The
findings concerning the hypertrophy of the quadriceps especially in the High Volume Group (HVG) (45 sets) are
impressive. Some limitations that should be taken into account in interpreting the findings are that
the sample was young men who apparently have a greater capacity for recovery. Middle-aged, or even
older ages would probably not be able to recover from such heavy training loads. Also
while the human body can respond well to intense physical stress for relatively short durations, such as
of the programme, its prolonged continuation is almost certain to lead to a syndrome of
overtraining. In addition, the fact that no measurements were taken at any point near the midpoint of the duration,
cannot exclude the possibility that HVG presented a plateau and continued to operate under these conditions.
conditions.
In Amirthalingam et al’s 2017¨German Volume Study¨ (1) it was found that energy intake in both the
two groups increased by an estimated 1020 kj , the group of 5 sets increased more (%) and the total,
in addition to the lean body mass. This result indicates that the daily average had not been successfully calculated.
caloric consumption. If the positive caloric balance was the same in both groups, or an increase in the total caloric
mass would be the same and the difference would only focus on muscle hypertrophy. The above case
is enhanced by the difference between total and lean mass between the two groups. In the 5 set group the
difference was 0.9% while in the 10 set group it was only 0.2%.So more of the weight gain occurred
in HVG from muscle mass growth. A fact that is not taken into account by researchers and is not interpreted.
Also, HVG in order to cope with the very difficult training protocol, performed the sets with
5% less intensity of 1 RM . We can safely speculate that if the total weekly
sets had been distributed with a different spit and a higher training frequency, this would not have been observed
the phenomenon.
In the research of Heaselgrave, Samuel R; Blacker, Joe; Smeuninx, Benoit; McKendry, James; Breen, Leigh 2019 (5) while the
trainees were exercised to measure muscle hypertrophy of the biceps brachii , were selected in addition to
dumbbell pulls from a seated position with the palm of the hand in a prone position and two exercises in which most of the work
produce other muscle groups. Those of the back. These were the rowing with bar and the pulls in lat
machine. Both of them with the palm of their hand in a sleeper hold. It is not clear from the investigation why this
option, which could potentially change its results. Also the fact that it allowed the
training and outside research (albeit with the note not to involve the arm flexors) will
could positively or negatively influence the hormonal environment, favouring or not favouring hypertrophy.
Στην έρευνα των Karl J. Ostrowski , Greg J. Wilson , Robert P Weatherby , Peter W. Murphy, Andrew Lyttle 1997 (8)
there was a drop in the testosterone to cortisol ratio which the researcher interpreted as
possible overtraining in the group of 12 sets.He does not evaluate whether the high training volume
gave a sharp increase in training loads compared to the previous load received by the sample and
whether this may ultimately have led to the relatively negative consequence for the intended outcome. Perhaps the
the body has not been able to absorb the training loads and adapt.
Higher training volume is probably more conducive to hypertrophy in the lower limbs.
There is no mention of a break between sets and whether and how nutritional needs are met.
In the study by Radaelli et al. 2015 (10) Although there were no statistically significant differences for the flexors
of the elbow in hypertrophy, gave statistically significantly higher values in the elbow extensors for
HVG , as well as a greater increase in lean muscle mass.There was no nutritional monitoring and
intervention (all participants consumed the meals of the military academy they were attending).
So the HVG, despite having a higher ascetic catabolism, took in the same calories.
However, it showed a greater increase in total lean mass.

In the study by Matheus Barbalho et al. 2018 (2), at the dietary level, neither the caloric
intake based on caloric consumption – needs, but also the ratio of macronutrients,
as a result we do not know whether and to what extent these needs were increased, especially in the HV groups. The
non-linear periodization included 6 weeks with sets of 4-6 repetitions that do not favor the
hypertrophy and another 6 weeks with sets of 6-8 reps that are within the limits of the commonly
considered ideal number of repetitions.
In the study by Gerald T Mangine et al. 2015 (7) the authors admit that a major limitation of the
research was the untested in-depth coaching background of the participants, in addition to their coaching
age. Also, although dietary intake was monitored, no guidelines were given based on caloric
consumption of each group and recommendations for minimum protein intake.
In the study by Felipe Damas et al. 2019 (4) there seemed to be a large difference in individual
response to the training volume , but also that the training protocol had been chosen to be applied to the
same individual did not allow to demonstrate the possible different hormonal responses which would
were correlated with training volume. Also possibly the choice of exercise (monoarticular to
affected them).
Conclusions cannot be generalised because such a research option does not take into account the
systemic fatigue

* (WTF) Weekly Training Frequency,((MT) Muscle Thickness, (BP) Bench Press, (MP) military press, (LPD)lateral pull down, (SCR)seated cable row,(BS)back squat,(LP) leg press, (LE) leg extension,

(DL) dumbbell lounges, (LC) leg curls, (CR)calf raisers ,(IBP) incline bench press,(UR)upright row, (TPD)triceps push down,(SSBC) seated supine biceps curls,(SGBOR) supine grip bent over rows,

(SGPD) supine grip pull downs, (SLDL) Stiff leg dead lift, (SLC) single leg curl, (TBPD) T- bar pull down,(CP) Calf press, (SCR) seated calf raisers(BC)biceps curl,(TE) triceps extensions,(BBOR) Barbell bent over row,(IBP)incline bench Press,(DLF)dumbbell lateral flyes

1. Amirthalingam T, yorgi mavros, guy c.wilson, jillian l. clarke, lachlanmitchell,and daniel a. Hackett 2017

Effects of a modified German volume training program on muscular hypertrophy and strength

J Strength Cond Res. 2017

2. Barbalho Matheus, Victor Silveira, Coswig , James Steele, James P. Fisher,Antonio Paoli, Paulo Genti

Evidence for an Upper Threshold for Resistance Training Volume in Trained Women.

October 2018 Medicine & Science in Sports & Exercise 51

3. Burd NA, Holwerda AM, Selby KC, West DW, Staples AW, Cain NE, Cashaback JG, Potvin JR, Baker SK, Phillips S

Resistance exercise volume affects myofibrillar protein synthesis and anabolic signaling molecule phosphorylation in young men.

J Physiol.2010;588:3119–30

4. Damas Felipe, Barcelos Cintia, Sanmy r. Brega No ´, Ugrinowitsch Carlos, Manoel e. Lixandra˜o, Lucas M. E. D. Santos, Miguel S. Conceic¸ a˜o, Felipe C. Vechin, Andcleiton A. Libardi 2019 .

Individual muscle hypertrophy and strength responses to high vs. low resistance training frequencies .

J Strength Cond Res. 2019 .

• Heaselgrave, Samuel R; Blacker, Joe; Smeuninx, Benoit; McKendry, James; Breen, Leigh 2019.

Dose-Response of Weekly Resistance Training Volume and Frequency on Muscular Adaptations in Trained Males

Int J Sports Physiol Perform. 2019.

6. Krieger, 2009

Single versus multiple sets of resistance exercise: A meta-regression.

JW. J Strength Cond Res 23: 1890–1901, 2009

7. Gerald T Mangine, Jay R Hoffman, Adam M Gonzalez, Jeremy R Townsend, Adam J Wells, Adam R Jajtner,Kyle S Beyer Carleigh H Boone, Amelia A Miramonti, Ran Wang, Michael B LaMonica, David H Fukuda,Nicholas A Ratamess, and Jeffrey R Stout 2015

The effect of training volume and intensity on improvements in muscular strength and size in resistance-trained men

Physiol Rep. 2015

8. Ostrowski Karl J. , Wilson Greg J., Weatherby Robert P , Murphy Peter W. , Andrew Lyttle 1997.

The Effect of Weight Training Volume on Hormonal Output and Muscular Size and Function

The Journal of Strength and Conditioning Research August 1997.

9. Gordon Peterson MD, Sen A, PM. 2011

Influence of resistance exercise on lean body mass in aging adults: a meta-analysis.

Sci Sports Exerc. Med 2011;43:249–58.

10. Radaelli R, Fleck SJ, Leite T, Leite RD, Pinto RS, Fernandes L, Simão R. J Strength Cond Res. 2015.

Dose-response of 1, 3, and 5 sets of resistance exercise on strength, local muscular endurance, and hypertrophy.

11. Schoenfeld BJ, Contreras B, Krieger J, Grgic J, Delcastillo K, Belliard R, Alto A 2019

Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men.

12. Brad J. Schoenfeld , Dan Ogbornb and James W. Krieger 2016

Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis

13. Terzis G, Spengos K, Mascher H, et al.2010

The degree of p70 S6k and S6 phosphorylation in human skeletal muscle in response to resistance exercise depends on the training volume.

Eur J Appl Physiol. 2010;110:835–43