Machek, SB, Cardaci, TD, Wilburn, DT, Cholewinski, MC, Latt, SL, Harris, DR, and Willoughby, DS. Neoprene knee sleeves of varying tightness augment barbell squat one repetition maximum performance without improving other indices of muscular strength, power, or endurance. J Strength Cond Res 35(2S): S6–S15, 2021—Neoprene knee sleeves are commonly used by powerlifters and recreational users but are heavily under-researched. Furthermore, no data exist on whether knee sleeves of varying compressive tightness impact muscular performance similar to commonly used knee wraps, which are both generally effective and more so when increasingly constrictive. Fifteen resistance trained, knee sleeve naive, recreational weight lifting men (22.1 ± 4.1 years; 177.5 ± 5.9 cm; 87.8 ± 7.8 kg) visited the laboratory on 3 separate occasions one week apart, assigned in a randomized, crossover, and counterbalanced fashion to either a minimally supportive control sleeve (CS) condition, a manufacturer-recommended sizing neoprene knee sleeve (“normal” sleeve; NS), or a one size smaller (than NS) neoprene knee sleeve (tighter sleeve [TS]). On each visit, subjects sequentially completed vertical jump (countermovement and squat jumps for both peak and mean power), one repetition maximum (1RM) barbell squat, and GymAware assessments (peak power, peak velocity, and dip) at 90% (reported) and 100% (tested) 1RM as well as one-leg extension (1RM, repetitions to failure, and total volume load at 75% 1RM) tests. All data were analyzed using one-way repeated measures analysis of variance at p < 0.05. Analysis revealed a significant condition effect on barbell squat 1RM (p = 0.003; η2 = 0.339), whereby both NS (p = 0.044; 166 ± 24 kg) and TS (p = 0.019; 166 ± 21 kg) outperformed CS (161 ± 22 kg), with no difference between neoprene sleeves. Conversely, no other tested parameters differed between knee sleeve conditions (p ≥ 0.05). The present results demonstrate that neoprene knee sleeves may function independent of tightness, relative to recommended sizing and ultimately unlike knee wraps. Furthermore, the singular benefits observed on barbell squat maximal strength potentially suggests an exercise-specific benefit yet to be fully elucidated.
Several previous investigations have employed betaine supplementation in randomized controlled crossover designs to assess its ostensible ergogenic potential. Nevertheless, prior methodology is predicated on limited pharmacokinetic data and an appropriate betaine-specific washout period is hitherto undescribed. The purpose of the present pilot investigation was therein to determine whether a 28 day washout period was sufficient to return serum betaine concentrations to baseline following a supplementation protocol. Five resistance-trained men (26 ± 6 y) supplemented with 6 g/day betaine anhydrous for 14 days and subsequently visited the lab 10 additional times during a 28 day washout period. Participants underwent venipuncture to assess serum betaine and several other parameters before (PRE) and periodically throughout the washout timeframe (POST0, -4, -7, -10, -13, -16, -19, -22, -25 and -28). All analyses were performed at a significance level of p < 0.05. While analyses failed to detect any differences in any other serum biomarker (p > 0.05), serum betaine was significantly elevated from PRE-to-POST0 (p = 0.047; 2.31 ± 1.05 to 11.1 ± 4.91 µg·mL−1) and was statistically indistinguishable from baseline at POST4 (p = 1.00). Nevertheless, visual data assessment and an inability to assess skeletal muscle concentrations would otherwise suggest that a more conservative 7 day washout period is sufficient to truly return both serum-and-skeletal muscle betaine content to pre-supplementation levels.
The purpose of this investigation was to compare the impacts of a potential blood flow restriction (BFR)-betaine synergy on one-leg press performance, lactate concentrations, and exercise-associated biomarkers. Eighteen recreationally trained males (25 ± 5 y) were randomized to supplement 6 g/day of either betaine anhydrous (BET) or cellulose placebo (PLA) for 14 days. Subsequently, subjects performed four standardized sets of one-leg press and two additional sets to muscular failure on both legs (BFR [LL-BFR; 20% 1RM at 80% arterial occlusion pressure] and high-load [HL; 70% 1RM]). Toe-tip lactate concentrations were sampled before (PRE), as well as immediately (POST0), 30 min (POST30M), and 3 h (POST3H) post-exercise. Serum homocysteine (HCY), growth hormone (GH) and insulin-like growth factor-1 concentrations were additionally assessed at PRE and POST30M. Analysis failed to detect any significant between-supplement differences for total repetitions completed. Baseline lactate changes (∆) were significantly elevated from POST0 to POST30 and from POST30 to POST3H (p < 0.05), whereby HL additionally demonstrated significantly higher ∆Lactate versus LL-BFR (p < 0.001) at POST3H. Although serum ∆GH was not significantly impacted by supplement or condition, serum ∆IGF-1 was significantly (p = 0.042) higher in BET versus PLA and serum ∆HCY was greater in HL relative to LL-BFR (p = 0.044). Although these data fail to support a BFR-betaine synergy, they otherwise support betaine’s anabolic potential.
Exercise-induced muscle damage (EIMD) protocols are designed to elicit adequate amounts of muscle damage to study their effects on recovery but may offer minimal real-world application. Combined short duration downhill running (DR) and plyometric (PLY) training may be a more conducive EIMD model for making generalizations to athlete and military populations. PURPOSE: To compare the effect of a DR+PLY EIMD protocol to a DR only and a PLY only model on indirect markers of muscle damage. METHODS: Six recreationally trained men (age: 28.5 ± 4.1, BMI: 29.4 kg/m 2 ± 5.5) completed three EIMD protocols in a random-order, crossover design. Participants completed a baseline anthropometric assessment and VO 2max test (Bruce Protocol). Each participant was randomized to 1 of 3 muscle damage protocols: A) 20 mins of DR at 70% VO 2max then 5 x 20 reps of jumping lunges (2 min rest) (DR+JL), B) DR only, and C) JL only. Serum creatine kinase (CK) was collected and perceived muscle soreness was assessed using a 10-cm visual analog scale (VAS) at rest (R), extended (E), and active (A), at 6 timepoints (PRE, post 0-, 1-, 24-, 48, and 72-hrs). A mixed-model repeated measures ANOVA with appropriate post-hoc analysis was performed to determine the effect of condition on %∆ CK and VAS outcomes over time. Significance was set at p < .05. RESULTS: CK and all VAS measures significantly increased over time (T, p < .05). For CK, there was a significant group (G, p = .006) and GxT (p = .001) effect. The %∆ in CK was significantly higher in the DR+JL condition compared to DR (p = .029) and JL (p = .007). Of note, only the DR and JL conditions had participants that had CK values that did not rise above the reference range (> 340 U•L -1 ). For muscle soreness there were only condition differences for VAS-E (p = .011) and VAS-A (p < .001). For VAS-E, the DR+JL condition was significantly higher than JL (p = .011). For VAS-A, DR+JL and DR were significantly higher than JL (p < .05). CONCLUSION: An EIMD protocol using a combination of two modalities (DR+JL) appears to provide an adequate CK and muscle soreness response that makes it acceptable for the study of muscle damage and applicable to real-world training scenarios compared to single models. In addition, muscle soreness assessed by VAS should include conditions requiring movement to determine the effect of functional recovery from EIMD.
LGD-4033, a selective androgen receptor modulator, and MK-677, a growth hormone secretagogue, are being used increasingly amongst recreationally active demographics. However, limited data exist describing their effects on health-and androgen-related biomarkers. The purpose of this case study was to determine changes in body composition and biomarkers during and after continued coadministration of LGD-4033 and MK-677. We also aimed to examine muscular strength and intramuscular androgen-associated biomarkers relative to non-users.A 25-year-old male ingested LGD-4033 (10 mg) and MK-677 (15 mg) daily for 5 weeks. Blood and body composition metrics were obtained pre-, on-and postcycle. One-repetition maximum leg and bench press, in addition to intramuscular androgens and androgen receptor content, were analysed on-cycle. We observed pre-to on-cycle changes in body composition (body mass, +6.0%; total lean body mass, +3.1%; trunk lean body mass, +6.6%; appendicular lean body mass, +4.3%; total fat mass, +15.4%; trunk fat mass, +2.8%; and appendicular fat mass, +14.8%), bone (bone mineral content, −3.60%; area, −1.1%; and bone mineral density, −2.1%), serum lipid-associated biomarkers (cholesterol, +14.8%; triglycerides, +39.2%; lowdensity lipoprotein-cholesterol, +40.0%; and high-density lipoprotein-cholesterol, −36.4%), liver-associated biomarkers (aspartate aminotransferase, +95.8%; and alanine aminotransferase, +205.0%) and androgen-associated biomarkers (free testosterone, −85.7%; total testosterone, −62.3%; and sex hormone-binding globulin, −79.6%); however, all variables returned to pre-cycle values post-cycle, apart from total fat mass, appendicular fat mass, bone area, total cholesterol and low-density lipoprotein-cholesterol. Follicle-stimulating hormone was below clinical reference values on-(1.2 IU/L) and post-cycle (1.3 IU/L). Intramuscular androgen receptor (−44.6%), testosterone (+47.8%) and dihydrotestosterone (+34.4%), in addition to one-repetition maximum leg press and bench press (+39.2 and +32.0%, respectively),This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
FINAL WORKING DIAGNOSIS: cEDS patient POD5 of left ruptured patellar tendon repair with septic joint leading to necrotizing fasciitis on left anterior medial knee. TREATMENT AND OUTCOMES: Once suspicious of necrotizing fasciitis, he was urgently taken to the OR with orthopedic and general trauma surgery for incision and drainage with debridement requiring multiple washout procedures. On POD 14, he underwent a final surgery of the medial gastrocnemius flap placed over anterior knee joint and a four-point external fixator placed into his femur and tibia to allow ligamental healing. He had a wound VAC placed over his left knee and was discharged on IV antibiotics.
Purpose: Wrist wraps are regularly incorporated by competitive powerlifters, but several product-specific variations may influence any potential ergogenic benefits. In addition, the prevalence of athletic wrist wrap use is hitherto undescribed. Methods: Seventy actively competing powerlifters (n=70; 27±6y) who competed in the last two years were randomly recruited at sanctioned meets, whereby wrist wrap use descriptive data (wrap style [F or S], wrap length, and events used), wrap tightness (assessed via pulse oximeter-detected oxygen saturation (SpO2) and subjective discomfort [Borg CR10+]), as well as post-meet bench press one repetition maximum (1RM) were collected. Wrist wrap use prevalence data (wrap style, wrap length, and events used) were compared across TX, NC/SC, and CA regions, along with any potential correlations between both region-collapsed wrapped SpO2 and bench press. Finally, predictors of bench press 1RM (weight [kg], age [y], stiff wrap, wrap length, wrapped discomfort [WCR10+], and WSpO2) were assessed using linear regression, whereby all aforementioned statistical analyses were set at a significance level of p<.05. Results: Analyses failed to detect any significant regional differences in wrap style, length, or events used (p>0.05). Moreover, linear regression analysis revealed a significant effect (r2= 0.851, p = 0.02) where weight solely predicted bench press 1RM (p = 0.0433). Conclusions: Although we failed to detect any significant wrist wrap relationships, actively competing powerlifters nonetheless prominently utilize wraps across the regions assessed. Therefore, the potential for wrist wraps to augment bench press performance warrants further elucidation in a controlled, standardized investigation.
Blood flow restriction (BFR) may become ineffective or potentially dangerous without sufficient standardization. The purpose of this investigation was therefore to (1) assess the viability of multiple sizes of a novel BFR cuff to determine arterial occlusion pressure (AOP) and (2) compare resting arterial, venous and calf muscle pump (cMP)-mediated blood flow between the aforementioned conditions and a commonly employed wide-rigid, tourniquet-style cuff. In randomized, counter-balanced, and crossover fashion, 20 apparently healthy males (18–40 years) donned a widely employed wide-rigid (WR) cuff, along with the largest (NE) and manufacturer-recommended sizes (NER) of a novel narrow-elastic cuff. Participants subsequently assessed AOP, as well as (at 80%AOP) arterial, venous, and venous cMP flow relative to baseline values via ultrasound. All analyses were performed at a significance level of p < 0.05. Analyses revealed a significant condition effect for AOP (p < 0.001; ηp2 = 0.907) whereby WR was significantly lower than both NE and NER; in addition, the latter two did not differ. Compared with baseline, there were no statistically significant differences between cuffs for either arterial or cMP-mediated blood flow. Unsurprisingly, no participants demonstrated venous blood flow at 80% AOP. These findings support the viability of a novel narrow-elastic BFR product, evidenced by consistent AOP acquisition and equivocal blood flow parameters.
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