Determining Changes in Muscle Size and Architecture After Exercise Training: One Site Does Not Fit all.

ABSTRACT: Nunes, JP, Blazevich, AJ, Schoenfeld, BJ, Kassiano, W, Costa, BDV, Ribeiro, AS, Nakamura, M, Nosaka, K, and Cyrino, ES. Determining changes in muscle size and architecture after exercise training: One site does not fit all. J Strength Cond Res 38(4): 787-790, 2024-Different methods can be used to assess muscle hypertrophy, but the effects of training on regional changes in muscle size can be detected only using direct muscle measurements such as muscle thickness, cross-sectional area, or volume. Importantly, muscle size increases vary across regions within and between muscles after resistance training programs (i.e., heterogeneous, or nonuniform, muscle hypertrophy). Muscle architectural changes, including fascicle length and pennation angle, after resistance and stretch training programs are also region-specific. In this paper, we show that the literature indicates that a single-site measure of muscle shape does not properly capture the effects achieved after exercise training interventions and that conclusions concerning the magnitude of muscle adaptations can vary substantially depending on the muscle site to be examined. Thus, we propose that measurements of muscle size and architecture should be completed at multiple sites across regions between the agonist muscles within a muscle group and along the length of the muscles to provide an adequate picture of training effects.

Acute Effects of Different Set Configurations on Neuromuscular, Metabolic, and Perceptual Responses in Young Women.

We compared neuromuscular, metabolic, and perceptual responses between different resistance training configurations in young women. In a counterbalanced randomized order, 13 young women performed the following protocols in separate sessions (sets x repetitions): traditional (TRAD): 5x10, 90-s of rest interval between sets; more frequent and shorter total rest (FSR): 10x5, 30-s of rest interval between sets. The sessions were composed of leg press exercise with the same intensity. Force (maximum voluntary isometric contraction [MVIC]) and metabolic (lactate concentration) responses were measured pre- and post-resistance training sessions. The rating of perceived exertion (RPE) was measured after each set. The internal training load was calculated using the session-RPE method. There was a significant reduction in the MVIC only after TRAD configuration (Effect size [ES] = 0.36). The lactate concentration increased in both conditions but was higher after TRAD (ES = 2.81) than FSR (ES = 1.23). The RPE has progressively increased in both configurations. On the other hand, the internal training load was lower in the FSR configuration. From our findings, we suggest that more frequent and shorter total rest is an effective strategy for maintaining the ability to produce force, generating less metabolic stress and lower perceived internal load in young women.

The Effects of Carbohydrate Intake on Body Composition and Muscular Strength in Trained Men Undergoing a Progressive Resistance Training.

This study's purpose was to compare the effects of different carbohydrate (CHO) intakes on body composition and muscular strength following eight weeks of resistance training (RT) in pre-conditioned men. In addition, we explored the individual responses to different CHO intakes. Twenty-nine young men volunteered to participate in this study. The participants were divided into two groups according to their relative CHO intake: lower (L-CHO; n = 14) and higher (H-CHO; n = 15). Participants performed a RT program four days a week for eight weeks. The lean soft tissue (LST) and fat mass were determined by dual-energy X-ray absorptiometry. Muscular strength was determined by a one-repetition maximum (1RM) test in the bench press, squat, and arm curl exercises. Both groups increased LST (P < 0.05) with no statistical differences between conditions (L-CHO = +0.8% vs. H-CHO = +3.5%). Neither group demonstrated changes in fat mass. Both groups increased 1RM (P < 0.05) in the bench press (L-CHO = +3.6% vs. H-CHO = +5.8%) and squat (L-CHO = +7.5% vs. H-CHO = +9.4%); however, only H-CHO significantly increased arm curl 1RM (P < 0.05) at post-training (L-CHO = +3.0% vs. H-CHO = +6.6%). Responsiveness was greater in H-CHO vs. L-CHO for LST and arm curl 1RM. In conclusion, lower and higher CHO intakes promote similar increase in LST and muscular strength; however, a greater intake may improve the responsiveness to gains in lean mass and arm curl strength in pre-conditioned men.

Resistance Training for Older Women: Do Adaptive Responses Support the ACSM and NSCA Position Stands?

PURPOSE: The optimal intensity of resistance training (RT) to improve muscular, physical performance, and metabolic adaptations still needs to be well established for older adults. Based on current position statements, we compared the effects of two different RT loads on muscular strength, functional performance, skeletal muscle mass, hydration status, and metabolic biomarkers in older women. METHODS: One hundred one older women were randomly allocated to perform a 12-wk whole-body RT program (eight exercises, three sets, three nonconsecutive days a week) into two groups: 8-12 repetitions maximum (RM) and 10-15RM. Muscular strength (1RM tests), physical performance (motor tests), skeletal muscle mass (dual-energy X-ray absorptiometry), hydration status (bioelectrical impedance), and metabolic biomarkers (glucose, total cholesterol, HDL-c, HDL-c, triglycerides, and C-reactive protein) were measured at baseline and posttraining. RESULTS: Regarding muscular strength, 8-12RM promoted higher 1RM increases in chest press (+23.2% vs +10.7%, P < 0.01) and preacher curl (+15.7% vs +7.4%, P < 0.01), but not in leg extension (+14.9% vs +12.3%, P > 0.05). Both groups improved functional performance ( P < 0.05) in gait speed (4.6%-5.6%), 30 s chair stand (4.6%-5.9%), and 6 min walking (6.7%-7.0%) tests, with no between-group differences ( P > 0.05). The 10-15RM group elicited superior improves in the hydration status (total body water, intracellular and extracellular water; P < 0.01), and higher gains of skeletal muscle mass (2.5% vs 6.3%, P < 0.01), upper (3.9% vs 9.0%, P < 0.01) and lower limbs lean soft tissue (2.1% vs 5.4%, P < 0.01). Both groups improved their metabolic profile. However, 10-15RM elicited greater glucose reductions (-0.2% vs -4.9%, P < 0.05) and greater HDL-c increases (-0.2% vs +4.7%, P < 0.01), with no between-group differences for the other metabolic biomarkers ( P > 0.05). CONCLUSIONS: Our results suggest that 8-2RM seems more effective than 10-15RM for increasing upper limbs' muscular strength, whereas the adaptative responses for lower limbs and functional performance appear similar in older women. In contrast, 10-15RM seems more effective for skeletal muscle mass gains, and increased intracellular hydration and improvements in metabolic profile may accompany this adaptation.

Greater Gastrocnemius Muscle Hypertrophy After Partial Range of Motion Training Performed at Long Muscle Lengths.

ABSTRACT: Kassiano, W, Costa, B, Kunevaliki, G, Soares, D, Zacarias, G, Manske, I, Takaki, Y, Ruggiero, MF, Stavinski, N, Francsuel, J, Tricoli, I, Carneiro, MAS, and Cyrino, ES. Greater gastrocnemius muscle hypertrophy after partial range of motion training performed at long muscle lengths. J Strength Cond Res 37(9): 1746-1753, 2023-Whether there is an optimal range of motion (ROM) to induce muscle hypertrophy remains elusive, especially for gastrocnemius. This study aimed to compare the changes in gastrocnemius muscle thickness between calf raise exercise performed with full ROM (FULL ROM ), partial ROM performed in the initial (INITIAL ROM ), and final (FINAL ROM ) portions of the ROM. Forty-two young women performed a calf training program for 8 weeks, 3 days·week -1 , with differences in the calf raise ROM configuration. The calf raise exercise was performed in a pin-loaded, horizontal, leg-press machine, in 3 sets of 15-20 repetition maximum. The subjects were randomly assigned to 1 of the 3 groups: FULL ROM (ankle: -25° to +25°), INITIAL ROM (ankle: -25° to 0°), and FINAL ROM (ankle: 0° to +25°), where 0° was defined as an angle of 90° of the foot with the tibia. The muscle thickness measurements of medial and lateral gastrocnemius were taken by means of B-mode ultrasound. INITIAL ROM elicited greater medial gastrocnemius increases than FULL ROM and FINAL ROM (INITIAL ROM = +15.2% vs. FULL ROM = +6.7% and FINAL ROM = +3.4%; p ≤ 0.009). Furthermore, INITIAL ROM elicited greater lateral gastrocnemius increases than FINAL ROM (INITIAL ROM = +14.9% vs. FINAL ROM = +6.2%; p < 0.024) but did not significantly differ from FULL ROM (FULL ROM = +7.3%; p = 0.060). The current results suggest that calf training performed at longer muscle lengths may optimize gastrocnemius muscle hypertrophy in young women. Therefore, when prescribing hypertrophy-oriented training, the inclusion of the calf raise exercise performed with partial ROM in the initial portion of the excursion should be considered.

Muscle Swelling of the Triceps Surae in Response to Straight-Leg and Bent-Leg Calf Raise Exercises in Young Women.

ABSTRACT: Kassiano, W, Costa, B, Kunevaliki, G, Soares, D, Stavinski, N, Francsuel, J, Carneiro, MAS, Tricoli, I, Nunes, JP, Ribeiro, AS, and Cyrino, ES. Muscle swelling of the triceps surae in response to straight-leg and bent-leg calf raise exercises in young women. J Strength Cond Res 37(7): e438-e443, 2023-Triceps surae muscle swelling in response to different resistance exercises remains to be determined. This study compared the effects of straight-leg (STRA-leg) calf raise vs. bent-leg (BENT-leg) calf raise exercises on triceps surae muscle swelling. Seventeen young women (23.7 ± 4.0 years; 67.4 ± 16.0 kg; and 163.5 ± 7.2 cm) performed 2 resistance training sessions; in one, they performed the STRA-leg calf raise, and in another, they performed the BENT-leg calf raise. A randomized, cross-over, and counterbalanced design was adopted for this investigation. The subjects performed 4 sets of 20 repetitions maximum until concentric muscular failure. The muscle thickness of the gastrocnemius medial (GM), gastrocnemius lateral (GL), and soleus (SOL) was taken through B-mode ultrasound before and immediately after the calf raise exercises. STRA-leg calf raise elicited greater increases in muscle thickness of GM (+8.8% vs. -0.9%, p < 0.001) and GL (+14.5% vs. +7.0%, p < 0.001) than BENT-leg calf raise. Conversely, BENT-leg calf raise elicited greater increases in SOL muscle thickness than STRA-leg calf raise (+15.4% vs. +7.7%, p < 0.001). From a practical perspective, the STRA-leg calf raise should be preferred if the aim is stimulating the 3 muscles that comprise the triceps surae, whereas the BENT-leg calf raise should be prioritized if the target muscle is the SOL.

Effect of Different Load Intensity Transition Schemes on Muscular Strength and Physical Performance in Postmenopausal Women.

PURPOSE: In postmenopausal women, optimizing muscular strength and physical performance through proper resistance training (RT) is crucial in achieving optimal functional reserve later in life. This study aimed to compare if a higher-load-to-lower-load (HL-to-LL) scheme is more effective than a lower-load-to-higher-load (LL-to-HL) scheme on muscular strength and physical performance in postmenopausal women after 12 and 24 wk of RT. METHODS: Twenty-four postmenopausal women were randomized into two groups: LL-to-HL ( n = 12, 27-31 repetitions maximum (RM) in the first 12 wk, and 8-12RM in the last 12 wk) or HL-to-LL ( n = 12, 8-12RM during the first 12 wk, and 27-31RM in the last 12 wk). Muscular dynamic (1RM test) and isometric strength (MIVC) and functional tests (sit-to-stand power, 400-m walking, and 6-min walking) were analyzed at baseline, after 12 and 24 wk. RESULTS: Different load intensity transition schemes resulted in enhancements ( P < 0.05) in dynamic (45° leg press: LL-to-HL = 21.98% vs HL-to-LL = 16.07%; leg extension: LL-to-HL = 23.25% vs HL-to-LL = 16.28%; leg curl: LL-to-HL = 23.89% vs HL-to-LL = 13.34%) and isometric strength (LL-to-HL = 14.63% vs HL-to-LL = 19.42%), sit-to-stand power (LL-to-HL = 7.32% vs HL-to-LL = 0%), and walking speed (400-m test: LL-to-HL = 3.30% vs HL-to-LL = 5.52%; 6-min test: LL-to-HL = 4.44% vs HL-to-LL = 5.55%) after 24 wk of RT, without differences between groups ( P > 0.05). However, only the HL increased the dynamic strength in 45° leg press and leg extension and sit-to-stand power. Moreover, walking speed changes were more strongly correlated with the changes in MIVC ( P < 0.05). CONCLUSIONS: Our results indicate that both load intensity transition schemes produce similar improvements in muscular strength and physical performance in postmenopausal women after 24 wk of RT. However, the HL was more effective in increasing 45° leg press and leg extension strength, as well as power (mainly when performed after the LL), whereas having little effect on leg curl strength, isometric strength, and walking speed. Our findings suggest that although an HL makes a muscle isotonically stronger, it may have limited impact on isometric strength and walking speed in postmenopausal women.

Which ROMs Lead to Rome? A Systematic Review of the Effects of Range of Motion on Muscle Hypertrophy.

ABSTRACT: Kassiano, W, Costa, B, Nunes, JP, Ribeiro, AS, Schoenfeld, BJ, and Cyrino, ES. Which ROMs lead to Rome? a systematic review of the effects of range of motion on muscle hypertrophy. J Strength Cond Res 37(5): 1135-1144, 2022-Resistance exercise range of motion (ROM) influences muscular adaptations. However, there are no consistent practical guidelines about the optimal ROM for maximizing muscle hypertrophy. The objective of this article was to systematically review the literature for studies that compared the effects of full ROM (fROM) and partial ROM (pROM) on muscle hypertrophy. PubMed/MEDLINE, Scopus, and Web of Science databases were searched to identify articles from the earliest record up to and including April 2022. We calculated the effect size (ES) scores of the variables of interest. Eleven studies were included in the review. Full ROM and pROM performed in the initial part of the ROM elicited greater muscle hypertrophy of the rectus femoris, vastus lateralis, biceps brachii, and brachialis distal sites (between-groups ES: 0.20-0.90) than pROM performed in the final part of the ROM. fROM elicited greater muscle growth on the gluteus maximus and adductors than pROM in the final part of the ROM (between-groups ES: 0.24-0.25). Initial pROM produced more favorable proximal rectus femoris hypertrophy than fROM (between-groups ES: 0.35-0.38). pROM in the middle part of the ROM elicited greater triceps brachii hypertrophy than fROM (between-group ES: 1.21). In conclusion, evidence suggests that when training at a longer muscle length-through either pROM or fROM-some muscles, such as quadriceps femoris, biceps brachii, and triceps brachii, tend to experience optimal growth. Thus, the use pROM in the initial part of the excursion in combination with fROM training should be considered when prescribing hypertrophy-oriented resistance training programs.

Effect of Resistance Exercise Order on Cardiovascular Disease Risk Factors in Older Women: A Randomized Controlled Trial.

We compared the effects of two specific resistance training (RT) exercise orders on cardiovascular risk factors. Forty-four untrained older women (>60 years) were randomly assigned to three groups: control (CON, n = 15), multi-joint to single-joint (MJ-SJ, n = 14), and single-joint to multi-joint (SJ-MJ, n = 15) exercise orders. Training groups performed a whole-body RT program (eight exercises, 3 × 10−15 repetitions for each exercise) over 12 weeks in 3 days/week. Body fat, triglycerides, total cholesterol, HDL-c, LDL-c, VLDL-c, glucose, IL-6, IL-10, TNF-α, C-reactive protein, total radical-trapping antioxidant (TRAP), advanced oxidation protein products (AOPP), ferrous oxidation-xylenol (FOX), and nitric oxide concentrations (NOx) were determined pre- and post-intervention. Significant interaction group × time (p < 0.05) revealed reducing fat mass and trunk fat and improvements in glucose, LDL-c, IL-10, TNF-α, C-reactive protein, FOX, and AOPP concentrations in both training groups, without differences between them (p > 0.05). The results suggest that 12 weeks of RT, regardless of exercise order, elicit positive adaptations on body fat and metabolic biomarkers similarly in older women.

Regional phase angle, not whole-body, is augmented in response to pre-season in professional soccer players.

The objective of this article was to assess the effects of six-week pre-season training on whole-body and regional bioelectrical impedance analysis (BIA)-derived parameters, body composition, power, and aerobic performance in professional soccer players. Ten professional soccer athletes participated in the present study. Whole-body and regional hamstrings BIA-derived parameters [resistance, reactance, impedance, phase angle (PhA)], body composition, total body water (TBW), intracellular (ICW), and extracellular (ECW) were measured before, at mid-point, and after sixth week of the pre-season. Power (countermovement jump and squat jump) and aerobic capacity (Yo-Yo test) were measured before and after pre-season. There was a significant increase in the regional PhA (+13.9%) but not in the whole-body. There was a reduction in fat mass (-4.1%), an increase in fat-free mass (+1.7%), TBW (+8.3%), ICW (+8.8%), and ECW (+7.6%), as well as an increase in jump height (+11.0%) and distance covered in the Yo-Yo test (+34.7%). From our results, it is possible to suggest that pre-season training can induce an increase in hamstring PhA as well as body recomposition and improvement of physical fitness in professional soccer players.

Effect of Resistance Exercise Orders on Health Parameters in Trained Older Women: A Randomized Crossover Trial.

PURPOSE: This study aimed to compare the effects of four resistance exercise orders on muscular strength, body composition, functional fitness, cardiovascular risk factors, and mental health parameters in trained older women. METHODS: The intervention lasted 63 wk. Sixty-one physically independent women (>60 yr) after completing a 12-wk resistance training (RT) preconditioning phase were randomized into four different exercise orders groups to perform 12 wk of RT: multijoint to single-joint and upper- to lower-body, single-joint to multijoint and upper- to lower-body, multijoint to single-joint and lower- to upper-body, and single-joint to multijoint and lower- to upper-body. This was followed by a 12-wk detraining period and another 12-wk RT in which exercise orders were crossed over between MJ-SJ and SJ-MJ conditions. Body composition (dual-energy x-ray absorptiometry), muscular strength (one-repetition maximum tests), functional fitness (gait speed, walking agility, 30-s chair stand, and 6-min walk tests), cardiovascular risk factors (glucose, triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, C-reactive protein, advanced oxidation protein product, total radical-trapping antioxidant parameter, and nitric oxide), depressive (Geriatric Depression Scale) and anxiety symptoms (Beck Anxiety Inventory), and cognitive performance (Montreal Cognitive Assessment, Trail Making, verbal fluency, and Stroop test) were analyzed. RESULTS: After the final training period, all groups presented significant improvements ( P < 0.05) in almost all analyzed variables (muscular strength, body composition, functional tests, blood biomarkers, and mental health parameters), without significant difference among exercise orders. CONCLUSIONS: Our results suggest that RT exercise orders in which MJ, SJ, upper, or lower-body exercises are performed first have similar effects on health parameters in trained older women.

Effects of resistance training on body recomposition, muscular strength, and phase angle in older women with different fat mass levels.

AIMS: The concomitant increase in skeletal muscle mass (SMM) and decrease in fat mass has been termed body recomposition. This study aimed to analyze the influence of pre-training levels of fat mass on body recomposition, muscular strength, and (phase angle) PhA after 24 weeks of resistance training (RT) in older women. METHODS: Data from 99 older women (68.6 ± 5.7 years, 65.7 ± 8.6 kg, 155.1 ± 5.8 cm, 27.2 ± 3.1 kg/m2) was retrospectively analyzed. Participants were separated into tertiles according to the amount of fat mass at baseline as follows: low fat mass (L-FM, n = 33), moderate fat mass (M-FM, n = 33), and high fat mass (H-FM, n = 33). The participants underwent a RT program consisting of eight exercises, three sets per exercise, with a load between 8 and 15 RM, performed three times per week for 24 weeks. The SMM and fat mass were evaluated by dual-energy X-ray absorptiometry (DXA). Body recomposition was determined by the composite Z-score of changes in SMM and fat mass. One repetition maximum (1RM) tests in chest press, knee extension, and preacher curl were assessed to verify muscular strength. Bioimpedance was used to determine phase angle. RESULTS: Results indicated that after the RT period, a greater positive body recomposition was observed in the L-FM group than in M-FM and H-FM groups. Moreover, all groups increased muscular strength and phase angle with no significant difference among groups (P > 0.05). CONCLUSION: The present study results suggest that the initial amount of fat mass influences the body recomposition induced by RT in older women, with those with lower pre-training fat mass levels presenting higher levels of body recomposition. However, improvements in muscular strength and phase angle are not dependent on the amount of initial fat mass in older women.

Cardiovascular Responses to Unilateral, Bilateral, Upper, and Lower Limbs Resistance Exercise.

The effects of different resistance exercises on cardiovascular responses remain elusive. Therefore, the present study aimed to investigate acute cardiovascular responses to unilateral and bilateral upper and lower limb resistance exercise. Young healthy males (n = 22; 26.9 ± 5.4 years, 170.0 ± 6.0 cm, 77.0 ± 10.8 kg) participated in the present study. Four experimental sessions were carried out, each consisting of one of the four exercises: unilateral and bilateral knee extension, unilateral and bilateral biceps curl. Cardiovascular responses (heart rate; HR, systolic blood pressure; SBP, and rate-pressure product; RPP) were measured at rest and after each of the three sets in each resistance exercise. All sets were performed until concentric muscle failure with a rest interval of two min. The HR, SBP, and RPP progressively increased during all sessions with uni- and bilateral exercises of the lower and upper limbs. Importantly, bilateral exercises, mainly of the lower limbs, induced greater increases in HR, and RPP than unilateral exercises of the upper and lower limbs. Regarding SBP, bilateral knee extension exercise induced greater increases than unilateral biceps curl. From a practical standpoint, exercise professionals may consider prescribing unilateral upper and lower limb exercises to alleviate cardiovascular stress, because even when performed until concentric muscle failure, this exercise mode seems to induce lower cardiovascular demand during the resistance training session.

Differential Responsiveness for Strength Gain Between Limbs After Resistance Training in Older Women: Impact on Interlimb Asymmetry Reduction.

ABSTRACT: Nunes, JP, Marcori, AJ, Ribeiro, AS, Cunha, PM, Kassiano, W, Costa, BDV, Aguiar, AF, Nakamura, M, Mayhew, JL, and Cyrino, ES. Differential responsiveness for strength gain between limbs after resistance training in older women: Impact on interlimb asymmetry reduction. J Strength Cond Res 36(11): 3209-3216, 2022-The present study compared strength responses between preferred (PREF) and nonpreferred (N-PREF) legs in older women. Muscular strength was measured unilaterally using an isokinetic dynamometer and was analyzed for reproducibility scores, acute performance, and responsiveness to a resistance training (RT) program. One hundred eleven women (aged ≥60 years) performed 12 weeks of whole-body RT (3 times a week; 4 lower-body exercises). Reproducibility scores (intraclass correlation coefficient ≥0.920; following test-retests in part of the sample at pretraining; n = 19), average acute performances, and average strength gains (PREF = ∼6.9%; N-PREF = ∼7.2%) were similar between legs (p > 0.05). However, the individual analyses showed that some subjects were considered responders to strength gains in 1 leg, whereas nonresponders in the other. Nonetheless, when considering the responses in all strength tests, most subjects (91%) were considered responder to at least 1 measure. In addition, it was observed that the strength ratio between PREF/N-PREF legs was altered for those who presented some asymmetry at baseline, as the limbs became more symmetrical in all strength measures after the RT. In conclusion, we observed that some older women may have different levels of strength between legs; however, a traditional 12-week RT program with bilateral exercises can reduce such asymmetry by inducing greater strength gains in the weaker leg.

Muscular strength and skeletal muscle mass in 511 physically independent older women aged 60-88 years.

Although one-repetition maximum (1RM) and lean soft tissue (LST) are the most common measures to assess muscular strength and skeletal muscle mass in older adults, reference data is still missing. Therefore, the present study aimed to produce reference values for the 1RM tests and LST in physically independent older women. Furthermore, the effect of age and body segment on these outcomes was examined. Five hundred and eleven older women aged 60-88 years participated in the present study. The 1RM tests were performed on chest press, leg extension, and preacher curl exercises. Dual-energy X-ray absorptiometry exams were used to determine total and segmental LST. The 1RM and LST average values: chest press = 44.0 ± 11.1 kg, leg extension = 48.8 ± 11.8 kg, preacher curl = 21.6 ± 5.4 kg; trunk LST = 19.0 ± 2.7 kg, lower-limbs LST = 12.5 ± 1.9 kg, upper-limbs LST = 4.0 ± 0.7 kg, appendicular LST = 16.6 ± 2.6, total LST = 38.5 ± 5.2 kg. The age-related declines in 1RM chest press and leg extension were higher than in preacher curl. The present study provides reference values for 1RM of different body segments and total and segmental LST in older women. In addition, our results revealed a reduction of muscular strength and LST with increasing age, and the magnitude of the age-related strength reduction depends on the body segment analyzed.

Does Varying Resistance Exercises Promote Superior Muscle Hypertrophy and Strength Gains? A Systematic Review.

ABSTRACT: Kassiano, W, Nunes, JP, Costa, B, Ribeiro, AS, Schoenfeld, BJ, and Cyrino, ES. Does varying resistance exercises promote superior muscle hypertrophy and strength gains? A systematic review. J Strength Cond Res 36(6): 1753-1762, 2022-Fitness professionals routinely employ a variety of resistance training exercises in program design as a strategy to enhance muscular adaptations. However, it remains uncertain whether such an approach offers advantages over a fixed-exercise selection. The objective of this review was to review the effects of exercise variation on muscle hypertrophy and strength. A search of the literature was conducted using PubMed/MEDLINE, Scopus, and Web of Science databases. Eight studies were identified as meeting inclusion criteria. The combined total sample of the studies was N = 241, comprising all young men. The methodological quality of included studies was considered "good" and "excellent" based on the Physiotherapy Evidence Database Scale. The available studies indicate that varying exercise selection can influence muscle hypertrophy and strength gains. Some degree of systematic variation seems to enhance regional hypertrophic adaptations and maximize dynamic strength, whereas excessive, random variation may compromise muscular gains. We conclude that exercise variation should be approached systematically with a focus on applied anatomical and biomechanical constructs; on the contrary, employing different exercises that provide a redundant stimulus, as well as excessive rotation of different exercises (i.e., high frequency of change), may actually hinder muscular adaptations.

Does Varying Resistance Exercises for the Same Muscle Group Promote Greater Strength Gains?

ABSTRACT: Costa, BDV, Kassiano, W, Nunes, JP, Kunevaliki, G, Castro-E-Souza, P, Sugihara-Junior, P, Fernandes, RR, Cyrino, ES, and de Fortes, LS. Does varying resistance exercises for the same muscle group promote greater strength gains? J Strength Cond Res 36(11): 3032-3039, 2022-Two of the foremost principles of progression are progressive overload and variation. A way to vary within a resistance training (RT) program is to perform different exercises for the same muscle group; however, this strategy is still overlooked. The purpose of the present study was to compare strength adaptations between an RT routine that maintained the exercises fixed (N-VAR) and another that varied the exercises for the same muscle group during the weekly sessions (VAR). Twenty-three young men (23.3 ± 4.1 years) were randomly allocated to N-VAR ( n = 11) and VAR ( n = 12) conditions. The RT was performed 3 times a week for 9 weeks and consisted of a whole-body routine (3 sets of 8-12 repetitions). Maximum dynamic strength was assessed using the 1-repetition maximum test (1RM), and the isometric strength was assessed using an isokinetic dynamometer, before and after training. Following the training period, both groups increased the 1RM values in all exercises ( p ≤ 0.002), without significant differences between them ( p ≥ 0.20). In contrast, a greater increase ( p = 0.02) in isometric knee extension strength was showed to N-VAR (+12%) compared with VAR (+7%). There was no significant increase in both groups for isometric knee flexion strength (N-VAR, p = 0.10; VAR, p = 0.18). Our findings indicate that maintaining or varying the exercises for the same muscle group promotes similar adaptations in the maximum dynamic strength. In contrast, for the isometric strength in knee extension, maintaining the fixed exercises seems to be more interesting.

Moderate and Higher Protein Intakes Promote Superior Body Recomposition in Older Women Performing Resistance Training.

PURPOSE: Resistance training (RT) combined with appropriate dietary intake can promote a concomitant increase in skeletal muscle mass (SMM) and reduction in fat mass, a condition termed body recomposition. This study's primary purpose was to explore the effects of protein ingestion on body recomposition after 24 wk of RT in older women. METHODS: Data from 130 untrained older women (68.7 ± 5.6 yr, 66.5 ± 11.5 kg, 155.5 ± 6.0 cm, and 27.4 ± 4.0 kg·m-2) across six studies were retrospectively analyzed. The participants were divided into tertiles according to their customary protein intake (g·kg-1·d-1): lower (LP; n = 45), moderate (MP; n = 42), and higher (HP; n = 43) protein intake. Participants performed a whole-body RT program carried out over 24 wk (eight exercises, three sets, 8-15 repetitions, three sessions a week). SMM and fat mass were determined by dual-energy x-ray absorptiometry. RESULTS: All groups increased SMM from baseline (P < 0.05), with the HP and MP groups showing greater increases than the LP group (LP, 2.3%; MP, 5.4%; and HP, 5.1%; P < 0.05). Reductions in fat mass were similar for all three groups (LP, 1.7%; MP, 3.7%; and HP, 3.1%; P > 0.05). The composite z-score of the percentage changes from pretraining to posttraining indicated greater positive body recomposition values for HP and MP compared with LP (P < 0.05). CONCLUSIONS: Results suggest that protein intake is a moderating variable for body recomposition in older women undergoing RT, with a low protein intake having a less favorable effect on body recomposition.