Impact of adenotonsillectomy and palatal expansion on the apnea-hypopnea index and minimum oxygen saturation in nonobese pediatric obstructive sleep apnea with balanced maxillomandibular relationship: A cross-over randomized controlled trial.

OBJECTIVE: To determine the impact and best management sequence between adenotonsillectomy (AT) and rapid palatal expansion (RPE) on the apnea-hypopnea index (AHI) and minimum oxygen saturation (MinSaO2) in nonobese pediatric obstructive sleep apnea (OSA) patients presenting balanced maxillomandibular relationship. STUDY DESIGN/METHODS: Thirty-two nonobese children with balanced maxillomandibular relationship and a mean age of 8.8 years, with a graded III/IV tonsillar hypertrophy and maxillary constriction, participated in a cross-over randomized controlled trial. As the first intervention, one group underwent AT while the other underwent RPE. After 6 months, interventions were switched in those groups, but only to participants with an AHI > 1 after the first intervention. OSA medical diagnosis with the support of Polysomnography (PSG) was conducted before (T0), 6 months after the first (T1) and the second (T2) intervention. The influence of sex, adenotonsillar hypertrophy degree, initial AHI and MinSaO2 severity, and intervention sequence were evaluated using linear regression analysis. Intra- and intergroup comparisons for AHI and MinSaO2 were performed using ANOVA and Tukey's test. RESULTS: The initial AHI severity and intervention sequence (AT first) explained 94.9% of AHI improvement. The initial MinSaO2 severity accounted for 83.1% of MinSaO2 improvement changes. Most AHI reductions and MinSaO2 improvements were due to AT. CONCLUSIONS: Initial AHI severity and AT as the first intervention accounted for most of the AHI improvement. The initial MinSaO2 severity alone accounted for the most changes in MinSaO2 increase. In most cases, RPE had a marginal effect on AHI and MinSaO2 when adjusted for confounders.

A prospective histopathological analysis of the inferior turbinate: which functional parts should be preserved during turbinate surgery?

OBJECTIVE: Inferior turbinate (IT) hypertrophy-induced chronic nasal obstruction is one of the most common problems in rhinology. However, the histopathological analysis of the hypertrophic IT is unclear. Therefore, this study aimed to identify the histological changes and the most functional areas of the IT to assist otolaryngologists with improving and modifying surgical techniques and minimizing potential complications. METHODS: This prospective, cross-sectional study was conducted to evaluate the contribution of hypertrophic IT to nasal obstruction. For the analysis, a total of 38 adult patients (IT hypertrophy group and non-IT hypertrophy [control] group) were enrolled, and 131 specimens were obtained during the surgical procedures (IT hypertrophy group, endoscopic submucosal turbinoplasty and septoplasty; non-IT hypertrophy group, septoplasty). Intraoperative samples were collected from four sites of the IT to determine the dimensions, composition, and possible pathological changes in each individual site. The samples were analyzed using light microscopy. RESULTS: A comparison of the four sites of the IT in the IT hypertrophy group showed that the posterior end had the highest normal epithelium percentage, and cilia count. This suggests that preserving the functional part of the IT during surgery is crucial. Furthermore, a comparison of both groups in terms of basement membrane thickness and vessel wall thickness (p = 0.005 and p = 0.03, respectively) showed significant differences. CONCLUSION: Our findings can assist otolaryngologists select the most appropriate surgical procedures for IT hypertrophy. In addition, they advocate the importance of preserving the functional part of the IT during surgical intervention to achieve an efficiently working IT and avoid undesirable complications while improving the nasal airway passage. LEVEL OF EVIDENCE: Level 3.

Androgen receptor markers do not differ between nonresponders and responders to resistance training-induced muscle hypertrophy.

The aim of this study was to investigate whether baseline values and acute and chronic changes in androgen receptors (AR) markers, including total AR, cytoplasmic (cAR), and nuclear (nAR) fractions, as well as DNA-binding activity (AR-DNA), are involved in muscle hypertrophy responsiveness by comparing young nonresponder and responder individuals. After 10 wk of resistance training (RT), participants were identified as nonresponders using two typical errors (TE) obtained through two muscle cross-sectional area (mCSA) ultrasound measurements (2 × TE; 4.94%), and the highest responders within our sample were numerically matched. Muscle biopsies were performed at baseline, 24 h after the first RT session (acute responses), and 96 h after the last session (chronic responses). AR, cAR, and nAR were analyzed using Western blotting, and AR-DNA was analyzed using an ELISA-oligonucleotide assay. Twelve participants were identified as nonresponders (ΔmCSA: -1.32%) and 12 as responders (ΔmCSA: 21.35%). There were no baseline differences between groups in mCSA, AR, cAR, nAR, or AR-DNA (P > 0.05). For acute responses, there was a significant difference between nonresponders (+19.5%) and responders (-14.4%) in AR-DNA [effect size (ES) = -1.39; 95% confidence interval (CI): -2.53 to -0.16; P = 0.015]. There were no acute between-group differences in any other AR markers (P > 0.05). No significant differences between groups were observed in chronic responses across any AR markers (P > 0.05). Nonresponders and responders presented similar baseline, acute, and chronic results for the majority of the AR markers. Thus, our findings do not support the influence of AR markers on muscle hypertrophy responsiveness to RT in untrained individuals.NEW & NOTEWORTHY We explored, for the first time, the influence of androgen receptor (AR) through the separation of cytoplasmic and nuclear cell fractions [i.e., cytoplasmic androgen receptor (cAR), nuclear androgen receptor (nAR), and androgen receptor DNA-binding activity (AR-DNA)] on muscle hypertrophy responsiveness to resistance training. The absence of muscle hypertrophy in naïve individuals does not seem to be explained by baseline values, and acute or chronic changes in AR markers.

Aerobic Training With Blood Flow Restriction on Muscle Hypertrophy and Strength: Systematic Review and Meta-analysis.

ABSTRACT: de Lemos Muller, CH, Farinha, JB, Leal-Menezes, R, and Ramis, TR. Aerobic training with blood flow restriction on muscle hypertrophy and strength: systematic review and meta-analysis. J Strength Cond Res 38(7): 1341-1349, 2024-Integrating strength and endurance training in a single exercise session, even on separate days, can be physically demanding and time-consuming. Therefore, there is a growing interest in identifying efficient training methods that can concurrently enhance cardiovascular and neuromuscular performance through a singular training modality. This study conducted a systematic review and meta-analysis to explore the effects of aerobic training with blood flow restriction (AT + BFR) on muscle hypertrophy and strength gains in healthy individuals. Our study was registered at PROSPERO and used multiple databases (PubMed, Embase, Scopus, and Web of Science), seeking clinical trials that examined AT + BFR influence on muscle hypertrophy and strength gains in individuals aged 18-60 years and comparing with aerobic training without BFR. The risk of bias and method quality were assessed using the ROB2.0 tool and PEDro scale, respectively, and the quality of evidence was evaluated with the GRADE method. A random-effects model was used for meta-analysis, and standardized mean difference (SMD) was calculated for each outcome. Of 4,462 records, 29 full texts were assessed for eligibility, with 7 articles meeting the inclusion criteria. The results indicated that AT + BFR was more beneficial for inducing muscle hypertrophy than aerobic training without BFR (SMD [95% CI] = 0.86 [0.37-1.35]; I2 = 42%). Furthermore, AT + BFR was associated with greater improvements in muscle strength (SMD [95% CI] = 0.41 [0.10-0.72]; I2 = 0%). Despite the generally high risk of bias for both outcomes, these encouraging findings underscore the clinical significance of AT + BFR as a compelling tool for enhancing neuromuscular parameters.

Exploring botulinum toxin's impact on masseter hypertrophy: a randomized, triple-blinded clinical trial.

The present study aimed to assess the effectiveness and functional adverse effects of a single and multiple injections of botulinum toxin A (BoNT-A) for masseter hypertrophy (MH). Twenty-six women complaining about lower third facial enlargement due to MH, received 75 U of BoNT-A (abobotulinum toxin) in each masseter muscles. After 3 months, patients were randomly assigned to receive a second treatment session of Saline Solution: (G1; n = 11) or BoNT-A: (G2; n = 12). Muscle thickness (ultrasound), electrical activity (electromyography; EMG), masticatory performance, and subjective perception of MH were evaluated. Follow-up was performed at 1, 3 and 6 months. Muscle thickness, EMG activity, and masticatory performance were analyzed using ANOVA two-way and Sidak test as post-hoc. Masticatory performance was analyzed by the Friedman's test and Mann-Whitney test. Regarding inter-groups comparisons, there was a significant decrease in the left masseter muscle thickness in the G2 group at the 6 month follow-up (p < 0.02). For EMG, significant differences were evident at the 6 month assessment, with higher masseter activity for G1 (p < 0.05). For masticatory performance, no significant differences were observed throughout the study (p > 0.05) and a higher improvement in subjective perception of MH was observed in the 1 month follow-up for G2 (p < 0.05). In conclusion, BoNT-A is effective for MH, however multiple injections cause functional adverse effects in masseter muscle.

Temporalis Muscle Changes Following Botulinum Toxin A Injections in Masseter Hypertrophy Patients: A Randomized Triple-Blinded Trial.

BACKGROUND: This study aimed to elucidate the effects of botulinum toxin A (BoNT-A) treatment for patients diagnosed with masseter hypertrophy on the temporalis muscle, with a particular focus on assessing alterations in muscle thickness, electromyographic (EMG) activity, and the development of muscle pain. METHODS: The present randomized triple-blinded clinical trial enrolled 26 female participants aged between 25 and 50 years complaining about masseter hypertrophy. Participants received 75U of BoNT-A (abobotulinumtoxinA) in both masseter muscles and after three months were randomized to receive a second treatment session of saline solution (S-BoNT-A) or BoNT-A (M-BoNT-A). Longitudinal assessments included temporalis muscle thickness through ultrasound, EMG activity, subjective pain, and masseter prominence severity after one, three, and six months of the first injection session. Muscle thickness, EMG, and subjective pain were analysed using two-way ANOVA with repeated measures and post hoc Sidak test, and for masseter prominence severity, Friedman and Mann-Whitney tests were used. RESULTS: Regarding inter-group comparisons, a higher muscle thickness (p < 0.02) and a higher EMG activity (p < 0.01) were found in the M-BoNT-A group at the 6-month follow-up. For subjective pain assessments, inter-group comparisons showed a higher prevalence of painful regions in M-BoNT-A group at the 6-month follow-up (p < 0.02). No significant differences were found in masseter prominence severity at the 6 months assessment between groups. CONCLUSION: BoNT-A treatment for masseter hypertrophy lead to structural and functional changes in the temporalis muscle, presenting higher changes after multiple injections of this treatment. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

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.

Morita-Baylis-Hillman adduct 2-(3-hydroxy-1-methyl-2-oxoindolin-3-il) acrylonitrile (CISACN) ameliorates the pulmonary allergic inflammation in CARAS model by increasing IFN-γ/IL-4 ratio towards the Th1 immune response.

Combined allergic rhinitis and asthma syndrome (CARAS) is an airway-type 2 immune response with a profuse inflammatory process widely affecting the world population. Due to the compromise of quality of life and the lack of specific pharmacotherapy, the search for new molecules becomes relevant. This study aimed to evaluate the effectiveness of the Morita-Bailys-Hillman adduct (CISACN) treatment in the CARAS experimental model. Female BALB/c mice were ovalbumin (OVA) -sensitized and -challenged and treated with CISACN. The treatment decreased the eosinophil migration to the nasal and lung cavities and tissues and the goblet cell hyperplasia/hypertrophy, attenuated airway hyperactivity by reducing the hyperplasia/hypertrophy of the smooth muscle and the extracellular matrix's thickness. Also, the treatment reduced the clinical signs of rhinitis as nasal rubbing and sneezing in a histamine-induced nasal hyperreactivity assay. The immunomodulatory effect of CISACN was by reducing OVA-specific IgE serum level, and IL-33, IL-4, IL-13, and TGF-ß production, dependent on IFN-γ increase. Furthermore, the effect of CISACN on lung granulocytes was by decreasing the p-p38MAPK/p65NF-κB signaling pathway. Indeed, CISACN reduced the p38MAPK and p65NF-κB activation. These data demonstrated the anti-inflammatory and immunomodulatory effects of the CISACN with scientific support to become a pharmacological tool to treat airway inflammatory diseases.

Absceso periamigdalino bilateral. Reporte de un caso y revisión de las controversias en el diagnóstico y tratamiento / Bilateral peritonsillar abscess. A case report and review of controversies surrounding diagnosis and management

La presentación bilateral del absceso periamigdalino es poco frecuente. Su abordaje es controversial y se discute si realizar amigdalectomía en caliente versus diferida. Se presenta el caso de un paciente de sexo masculino, de 14 años, con odinofagia, trismo y fiebre. Presentaba hipertrofia amigdalina bilateral, pilares abombados y edema de paladar blando. Tomografía computada: hipertrofia amigdalina bilateral, con realce poscontraste, ambas con colección, edema con moderada estenosis faríngea. Se decidió internación para tratamiento endovenoso y amigdalectomía con drenaje bilateral. Resolución completa del cuadro con alta a las 48 horas. Ante la presencia de un absceso periamigdalino, debe considerarse la posibilidad de un absceso contralateral oculto. Debe ser diagnosticado y tratado adecuadamente para prevenir complicaciones. La amigdalectomía en caliente podría ser un tratamiento seguro y debería ser considerado en pacientes que serán sometidos a anestesia para drenaje. La decisión final debe ser determinada para cada caso en particular.

The bilateral presentation of peritonsillar abscess is uncommon. Its management is controversial and it has been argued whether a quinsy tonsillectomy or an interval tonsillectomy should be performed. Here we describe the case of a 14-year-old boy with sore throat, trismus, and fever. He had bilateral tonsillar hypertrophy, convex arches, and soft palate edema. Computed tomography: bilateral tonsillar hypertrophy, with post-contrast enhancement, both with collection, edema with moderate pharyngeal stenosis. The patient was hospitalized for intravenous therapy and tonsillectomy with bilateral drainage resulting in a complete resolution of his condition and discharge at 48 hours. In the presence of a peritonsillar abscess, an unsuspected contralateral abscess should be considered. It should be diagnosed and managed adequately to prevent complications. Quinsy tonsillectomy could be safe and should be considered in patients who will undergo anesthesia for abscess drainage. The final decision should be made for each patient on an individual basis.

Higher resistance training volume offsets muscle hypertrophy nonresponsiveness in older individuals.

The magnitude of muscle hypertrophy in response to resistance training (RT) is highly variable between individuals (response heterogeneity). Manipulations in RT variables may modulate RT-related response heterogeneity; yet, this remains to be determined. Using a within-subject unilateral design, we aimed to investigate the effects of RT volume manipulation on whole muscle hypertrophy [quadriceps muscle cross-sectional area (qCSA)] among nonresponders and responders to a low RT dose (single-set). We also investigated the effects of RT volume manipulation on muscle strength in these responsiveness groups. Eighty-five older individuals [41M/44F, age = 68 ± 4 yr; body mass index (BMI) = 26.4 ± 3.7 kg/m2] had one leg randomly allocated to a single (1)-set and the contralateral leg allocated to four sets of unilateral knee-extension RT at 8-15 repetition maximum (RM) for 10-wk 2 days/wk. Pre- and postintervention, participants underwent magnetic resonance imaging (MRI) and unilateral knee-extension 1-RM strength testing. MRI typical error (2× TE = 3.27%) was used to classify individuals according to responsiveness patterns. n = 51 were classified as nonresponders (≤2× TE) and n = 34 as responders (>2× TE) based on pre- to postintervention change qCSA following the single-set RT protocol. Nonresponders to single-set training showed a dose response, with significant time × set interactions for qCSA and 1-RM strength, indicating greater gains in response to the higher volume prescription (time × set: P < 0.05 for both outcomes). Responders improved qCSA (time: P < 0.001), with a tendency toward higher benefit from the four sets RT protocol (time × set: P = 0.08); on the other hand, 1-RM increased similarly irrespectively of RT volume prescription (time × set: P > 0.05). Our findings support the use of higher RT volume to mitigate nonresponsiveness among older adults.NEW & NOTEWORTHY Using a within-subject unilateral design, we demonstrated that increasing resistance training (RT) volume may be a simple, effective strategy to improve muscle hypertrophy and strength gains among older adults who do not respond to low-volume RT. In addition, it could most likely be used to further improve hypertrophic outcomes in responders.

Cycle of the sexual segment of the kidney: histological insights into the role of the urinary tract in the reproduction of male Notomabuya frenata (Squamata: Scincidae).

The kidneys of male Squamata have an important reproductive function as some portions of the nephron may undergo hypertrophy, characterizing the sexual segment of the kidney (SSK). Although its function is still not completely understood, it is believed that the secretions produced by the SSK may act in the maintenance of spermatozoa. In this study, we investigated the reproductive biology of males of Notomabuya frenata based on the seasonal variation of the SSK. We performed macroscopic and microscopic evaluations of the male reproductive tract of museum specimens to characterize the SSK cycle. The nephron portion in which hypertrophy was observed was the collecting duct with secretory granules accumulation in the apical portion. SSK hypertrophy was observed in all seasons, with the tubule diameter in autumn differing from spring and the epithelium height showing no variation. Alcian Blue reacted positively to acid mucopolysaccharides in all seasons. Periodic acid-Schiff's reacted positively to neutral mucopolysaccharides in all seasons, except autumn. Both stains reacted only in the collecting duct. In addition, spermatozoa were found in the lumen of the SSK of one specimen examined. Cycle of the SSK varied seasonally as does the chemical composition of the secretions produced by the collecting duct. The reflux of spermatozoa into SSK may indicate that (1) these secretions act in sperm maintenance, and (2) possibly there is communication between the seminal and urinary ducts.

Effect of Testosterone on the Thyroarytenoid Muscle and Lamina Propria of Female Rat Vocal Folds.

OBJECTIVE: To analyze the effects of androgen therapy on the thyroarytenoid (TA) muscle, expression of androgen receptors (ARs) and hyaluronic acid (HA) concentration in the vocal folds (VFs) of adult female rats. METHODS: Twenty-one adult female Wistar rats were divided into experimental and control groups. The experimental group received weekly intramuscular injections of nandrolone decanoate for 9 weeks. Following euthanasia and dissection of the VFs, histomorphometric analysis of the TA muscle, immunohistochemical evaluation of ARs, and measurement of HA concentration using the ELISA-like fluorimetric method were performed. RESULTS: The experimental group exhibited a significantly larger mean fiber cross-sectional area in the TA muscle compared to the control group (434.3 ± 68.6 µm2 versus 305.7 ± 110.1 µm2; p = 0.029), indicating muscle hypertrophy. There was no significant difference in the number of muscle fibers. The experimental group showed higher expression of ARs in the lamina propria (62.0% ± 30.3% versus 22.0% ± 22.8%; p = 0.046) and in the TA muscle (45.0% ± 22.6% versus 18.3% ± 9.8%; p = 0.024). There was no significant difference in the concentration of HA. CONCLUSION: Exposure of adult female rats to androgen therapy resulted in hypertrophy of the TA muscle and increased expression of ARs in the VFs. The TA muscle seems to be the primary target of testosterone action in the VF, and the up-regulation of ARs might contribute to the persistent deepening of the voice. LEVEL OF EVIDENCE: NA Laryngoscope, 134:2316-2321, 2024.

Bilateral peritonsillar abscess. A case report and review of controversies surrounding diagnosis and management. / Absceso periamigdalino bilateral. Reporte de un caso y revisión de las controversias en el diagnóstico y tratamiento.

The bilateral presentation of peritonsillar abscess is uncommon. Its management is controversial and it has been argued whether a quinsy tonsillectomy or an interval tonsillectomy should be performed. Here we describe the case of a 14-year-old boy with sore throat, trismus, and fever. He had bilateral tonsillar hypertrophy, convex arches, and soft palate edema. Computed tomography: bilateral tonsillar hypertrophy, with post-contrast enhancement, both with collection, edema with moderate pharyngeal stenosis. The patient was hospitalized for intravenous therapy and tonsillectomy with bilateral drainage resulting in a complete resolution of his condition and discharge at 48 hours. In the presence of a peritonsillar abscess, an unsuspected contralateral abscess should be considered. It should be diagnosed and managed adequately to prevent complications. Quinsy tonsillectomy could be safe and should be considered in patients who will undergo anesthesia for abscess drainage. The final decision should be made for each patient on an individual basis.

La presentación bilateral del absceso periamigdalino es poco frecuente. Su abordaje es controversial y se discute si realizar amigdalectomía en caliente versus diferida. Se presenta el caso de un paciente de sexo masculino, de 14 años, con odinofagia, trismo y fiebre. Presentaba hipertrofia amigdalina bilateral, pilares abombados y edema de paladar blando. Tomografía computada: hipertrofia amigdalina bilateral, con realce poscontraste, ambas con colección, edema con moderada estenosis faríngea. Se decidió internación para tratamiento endovenoso y amigdalectomía con drenaje bilateral. Resolución completa del cuadro con alta a las 48 horas. Ante la presencia de un absceso periamigdalino, debe considerarse la posibilidad de un absceso contralateral oculto. Debe ser diagnosticado y tratado adecuadamente para prevenir complicaciones. La amigdalectomía en caliente podría ser un tratamiento seguro y debería ser considerado en pacientes que serán sometidos a anestesia para drenaje. La decisión final debe ser determinada para cada caso en particular.

Repigmentation of the Nipple-Areola Complex following Free Nipple Grafting.

BACKGROUND: Free nipple grafting (FNG) is a technique historically used during breast reduction and top surgery for treatment of gender dysphoria to minimize nipple-areola complex (NAC) hypoperfusion and subsequent loss. One drawback of this approach is NAC hypopigmentation. The authors sought to quantify long-term pigmentation changes in the NAC after FNG. METHODS: A retrospective review of patients who underwent reduction mammaplasty or simple mastectomy with FNG from 2000 through 2020 at the authors' institution was conducted. Patients were included if they had preoperative, early, and late postoperative images. Images were analyzed using the National Institutes of Health's Image J software for pigmentation changes over time. RESULTS: Of the 151 patients identified, 56 patients (111 breasts) had complete imaging (macromastia, n = 47; oncologic, n = 4; gender dysphoria, n = 5). All patients had NAC hypopigmentation on early imaging, with 25.5% (SD 18.1%) of the NACs affected. On late imaging, 83 NACs (74.7%) experienced repigmentation, with only 8.7% (SD 7.3%) of the NAC area remaining hypopigmented. This represents a 67.2% resolution of pigmentation ( P < 0.001). Ten NACs (9.0%) had progression of hypopigmentation, and 17 NACs (15.3%) had no change. In a subset analysis by race, White patients had significantly greater area of NAC hypopigmentation on early postoperative imaging (White, 29.3% [SD 18.8%] versus Black, 18.3% [SD 14.0%]; P < 0.01). However, resolution of hypopigmentation was similar between the groups. CONCLUSIONS: Although partial hypopigmentation of the NAC is nearly universal after FNG, a majority of patients experience repigmentation, with low residual hypopigmentation at 1 year. These findings are useful for counseling patients with early pigmentation changes in addition to guiding surgical decisions about breast surgery with FNG. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Effects of Different Weekly Set Progressions on Muscular Adaptations in Trained Males: Is There a Dose-Response Effect?

PURPOSE: This study investigated the effect of progressively adding sets for the lower limb every 2 wk versus performing a constant set volume in resistance-trained males. METHODS: Thirty-one resistance-trained males (age = 24.4 ± 2.9 yr, height = 175.5 ± 6.5 cm, body mass = 80.1 ± 9.4 kg, body fat = 14.4% ± 3.1%, resistance training [RT] experience = 5.1 ± 2.2 yr; one-repetition maximum [1RM] barbell back squat: body mass ratio = 1.7 ± 0.1 a.u.) were randomly allocated into a constant group (CG, n = 10), a four-set progression group (4SG, n = 10) or a six-set progression group (6SG, n = 11). After a 2-wk washout period and another 2-wk familiarization period, participants performed a lower-limb training program twice a week for 12 wk. Maximum dynamic strength (1RM) in the barbell back squat, vastus lateralis cross-sectional area, and the sum of lateral thigh muscle thickness at 30%, 50%, and 70% of the femur length were assessed at baseline and after the 12-wk training program. RESULTS: Regarding 1RM, multiple comparisons revealed that 6SG elicited higher muscle strength gains than 4SG ( P = 0.002) and CG ( P < 0.0001), and 4SG had greater improvements than CG ( P = 0.023). Cross-sectional area and sum of lateral thigh muscle thickness showed no between-group differences ( P = 0.067 and P = 0.076, respectively). However, an inspection of 95% confidence intervals suggests a potential dose-response relationship, with results appearing to plateau in the higher volume conditions. CONCLUSIONS: Our results suggest that progressively adding four or six sets per week every 2 wk elicited greater lower-limb strength in resistance-trained individuals over a 12-wk training period. Although our findings indicate a possible small benefit for higher volume conditions regarding hypertrophic adaptations in this population, the limited certainty of our findings warrants caution.