Manipulating Resistance Training Variables to Induce Muscle Strength and Hypertrophy: A Brief Narrative Review

The regular practice of resistance training (RT) has been shown to induce relevant increases in both muscle strength and size. In order to maximize these adaptations, the proper manipulation of RT variables is warranted. In this sense, the aim of the present study was to review the available literature that has examined the application of the acute training variables and their influence on strength and morphological adaptations of healthy young adults. The information presented in this study may represent a relevant approach to proper training design. Therefore, strength and conditioning coaches may acquire a fundamental understanding of RT-variables and the relevance of their practical application within exercise prescription.

Pre-exhaustion Training, a Narrative Review of the Acute Responses and Chronic Adaptations

Pre-exhaustion (PE) is a popular resistance training strategy that involves performing a single-joint exercise followed by a multi-joint exercise with minimal recovery between the transition. This approach is widely used by bodybuilding athletes and resistance training (RT) enthusiasts with the aim of enhancing muscle strength and hypertrophy. The present paper aimed to provide a narrative review as to the effects of the PE method on different acute and chronic outcomes, and discuss relevant practical applications. When considering the body of literature as a whole, we conclude that current evidence does not support a benefit to the PE method compared to traditional RT models regarding chronic improvements in strength, hypertrophy and body composition. However, the heterogeneous study designs confound the ability to draw strong conclusions on the topic. Further investigations are warranted with strict control of study variables to better elucidate what, if any, benefits may be obtained by the PE method.

Rest-pause and drop-set training elicit similar strength and hypertrophy adaptations compared to traditional sets in resistance-trained males

The present paper aimed to compare the effect of drop-set (DS) and rest-pause (RP) systems versus traditional resistance training (TRT) with equalized total training volume on maximum dynamic strength (1RM) and thigh muscle thickness (MT).Twenty-eight resistance-trained males were randomly assigned to either RP (n = 10), DS (n = 9) or TRT (n = 9) protocols performed twice a week for 8 weeks. 1RM and MT of the proximal, middle and distal portions of the lateral thigh were assessed at baseline and post intervention.A significant time x group interaction was observed for 1RM (P = 0.025) in the barbell back squat after 8-weeks. Post hoc comparisons revealed that RP promoted higher 1RM than TRT (P = 0.001); no statistical differences in strength were observed between the other conditions. A significant main effect of time was revealed for MT at the proximal (P = 0.0001) and middle (P = 0.0001) aspects of the lateral thigh for all training groups; however, the distal portion did not show a time effect (P = 0.190). There were no between-group interactions for MT. Our findings suggest that RP promotes slightly superior strength-related improvements compared to TRT, but hypertrophic adaptations are similar between conditions. Novelty bullets • Rest-pause elicited a slightly superior benefit for strength adaptations compared to traditional resistance training. • Resistance training systems do not promote superior hypertrophic adaptations when total training volume is equalized. • Muscle thickness in distal portion of thigh are similar to baseline. Although modest, effect sizes tended to favor rest-pause.

Carbohydrate refeed does not modify GVT-performance following energy restriction in bodybuilders

Bodybuilding is a sport in which competitors' physiques are judged on their muscular size, symmetry, and leanness, as displayed in a number of different poses. In the pre-competitive period, bodybuilders attempt to reduce body fat stores as much as possible while maintaining fat-free mass (FFM). This is achieved via a sustained negative energy balance, generally induced by a combination of decreased energy intake and increased energy expenditure. This study aimed to assess the ability of bodybuilders to resist fatigue during resistance exercise based German Volume Training (GVT), as well as the affective response after carbohydrate refeed following four weeks of moderate or severe energy restriction. Eleven male bodybuilders (28.4 ± 2.3 years old) with experience in competitions were randomized into two groups: Moderate Energy Restriction (MER; n = 6) or Severe Energy Restriction (SER; n = 5). On the 2nd day (during energy restriction) and 7th day (during refeed) of the fourth week, both groups completed two leg press protocols involving the GVT method. After the first and last workout protocol subjects were assessed for muscle soreness using the visual-analog scale (VAS), rating of perceived exertion (RPE), affective response, lactate, and creatine kinase. Anthropometric analysis indicated that a reduction of 3.7 and 3.2% in body mass corresponded to a loss of 16.0 and 17.6% of fat mass for the MER and SER groups, respectively, with both groups maintaining FFM. Blood CK and VAS values were reduced only in SER. Our results suggest that a carbohydrate refeed may help to attenuate the perception of muscle soreness and maintain exercise performance, especially when severe energy restriction is combined with an intense training protocol such as GVT.

THE IMPACT OF QUARANTINE ON BODY IMAGE AND LIFESTYLE HABITS IN RESISTANCE TRAINING PRACTITIONERS

ABSTRACT Introduction In order to curb the abrupt advance of “Coronavirus Disease 2019” (COVID-19) and prevent the collapse of the health system, authorities around the world have opted for social distancing strategies that include closing gyms, among other measures. Objectives This study analyzed the effect of social distancing on resistance training practitioners’ quality of life and perception of body image in silhouette. Methods The volunteers were contacted through social media; data were collected between April 13 and 19, 2020, through a structured questionnaire, comprised of an Informed Consent Form, four questions about COVID-19 and restrictive measures; and twenty-nine questions designed to characterize the individuals’ habits; as well as the Short Form Health Survey 36 questionnaire. All the questionnaires were applied over the Internet, using Google Forms®. After collection, the data were tabulated and interpreted using the software program AppleNumbers®, and subsequently presented as mean, standard deviation and percentiles. Results The results revealed changes in perception of body image and decreased frequency and satisfaction with training. There was also an increase in sedentary behavior, food intake, and amount of sleep; and a reduction in parameters related to health and quality of life. Conclusions The strategy of social distancing, adopted to curb the progress of COVID-19, has harmful consequences for resistance training practitioners, such as increased calorie intake, stress and anxiety, as well as possible psychological effects. These consequences, in turn, lead to changes in self-perception of body image and in the quality of training. Level of Evidence III; Cross-sectional study of non-consecutive patients; without uniformly applied reference standard.

Pre-stretching of the Hamstrings Before Squatting Acutely Increases Biceps Femoris Thickness Without Impairing Exercise Performance

Background: Bilateral squat exercise is widely used in resistance training (RT) programs to increase lower limb strength and muscle mass, but this exercise does not result in significant hypertrophy of the hamstrings. It has been speculated that stretching between sets with a certain degree of tension results in muscle hypertrophy, while acute stretching could decrease performance during maximal contractions.

Objective: This study investigated the acute effects of hamstring stretching before bilateral squatting on muscle thickness (MT), electromyography (EMG), and total training volume (TTV) on exercise performance.

Methods: Fourteen resistance-trained young men, with ∼7.5 years of RT experience, performed the 10 repetition maximum (RM) for the barbell squat in two sessions (test–retest) separated by period after 48 h. Participants engaged in two resistance exercise conditions separated by a 1 week recovery interval: one session employed hamstrings stretching and the other did not include hamstrings stretching. Before and after each resistance exercise session, the thickness of the quadriceps muscles and biceps femoris long head were obtained by ultrasound imaging. Moreover, the EMG amplitudes for the quadriceps muscles, biceps femoris, and iliocostalis muscles were recorded during back squat performance. The TTV was also evaluated for each exercise session.

Results: A significant increase in MT was observed after every set in both conditions for the evaluated quadriceps muscles (all p < 0.05), while for the biceps femoris, this effect was found only in the stretching condition (p < 0.05). EMG activity increased in the rectus femoris, vastus lateralis, and vastus medialis for the stretching condition. For the non-stretching condition, activity only increased in the vastus lateralis and medialis. There was no difference in EMG activity for the biceps femoris and iliocostalis in both conditions.

Conclusion: Stretching the hamstrings immediately before each set of the back squat can be used to acutely increase biceps femoris thickness without impairing squat performance.

Effects of Pre-exhaustion Versus Traditional Resistance Training on Training Volume, Maximal Strength, and Quadriceps Hypertrophy

BACKGROUND

The pre-exhaustion (PreEx) method is used as a resistance training (RT) method to increase muscle mass, yet the chronic effects of this method are poorly understood.

OBJECTIVE

Although readily prescribed as a RT method for promotion of muscle hypertrophy, few researches give light to gains made after chronic PreEx RT. Therefore, we compared the effects of traditional versus PreEx RT programs on muscle strength, body composition, and muscular hypertrophy in adult males.

METHODS

Untrained subjects (age: 31.37 ± 6.83 years; height: 175.29 ± 5.52 cm; body mass: 82.04 ± 13.61 kg; 1RM leg press: 339.86 ± 61.17 kg; 1RM leg extension: 121.71 ± 11.93 kg) were submitted to 9 weeks of RT with weekly sessions. Traditional (TRT) group (n = 12) performed three sets at 45° of leg press exercise at 75% of 1RM, PreEx group (n = 12) completed a set to failure on a leg extension machine prior to the leg press, and the control (CON) group (n = 7) did not train. Maximum strength, muscle thickness, and body composition were analyzed.

RESULTS

PreEx group increased in maximal strength on leg press (16 ± 8%) and leg extension (17 ± 11%), while the TRT group improved by 15 ± 9 and 11 ± 4%, respectively. The thickness of the quadriceps muscles increased for both intervention groups. Specifically, the post-training thickness of the vastus lateralis was significantly higher for PreEx (55%) compared to the CON group. The TRT group presented a greater loss of total and thigh fat mass when compared with the PreEx method. These results were found in the presence of a lower training load for the PreEx group.

CONCLUSION

The PreEx training can decrease the total training volume while maintaining results in strength and hypertrophy when comparing to TRT. However, TRT may be optimal if the goal is to decrease fat mass.

Acute Effects of the New Method Sarcoplasma Stimulating Training Versus Traditional Resistance Training on Total Training Volume, Lactate and Muscle Thickness

Background: Trained subjects have difficulty in achieving continued results following years of training, and the manipulation of training variables through advanced resistance training (RT) methods is widely recommended to break through plateaus.

Objective: The purpose of the present study was to compare the acute effects of traditional RT (TRT) versus two types of sarcoplasma stimulating training (SST) methods on total training volume (TTV), lactate, and muscle thickness (MT).

Methods: Twelve trained males (20.75 ± 2.3 years; 1.76 ± 0.14 meters; body mass = 79.41 ± 4.6 kg; RT experience = 4.1 ± 1.8 years) completed three RT protocols in a randomly sequenced order: TRT, SST contraction type (SST-CT), or SST rest interval variable (SST-RIV) with 7 days between trials in arm curl (elbow flexors) and triceps pulley extension (elbow extensors) performed on the same day.

Results: The SST groups displayed greater acute biceps and triceps brachii (TB) MT versus the TRT session, with no difference in lactate levels between them. The SST-CT resulted in greater biceps and TB MT versus the SST-RIV session. The TTV was greater for the TRT session versus the SST sessions, except in the case of the elbow flexors (no difference was observed between TRT and SST-CT), and higher for the SST-CT versus the SST-RIV.

Conclusion: Trained subjects may benefit from using the SST method as this method may offer a superior MT stimulus and reduced training time, even with a lower TTV.