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Supplemental Digital Content is Available in the Text. Lewis, MH, Siedler, MR, Lamadrid, P, Ford, S, Smith, T, SanFilippo, G, Waddell, B, Trexler, ET, Buckner, S, and Campbell, BI. Sex differences may exist for performance fatigue but not recovery after single-joint upper-body and lower-body resistance exercise. J Strength Cond Res 36(6): 1498–1505, 2022—This study evaluated sex differences in performance recovery and fatigue during dynamic exercise. Twenty-eight resistance-trained males (n = 16) and females (n = 12) completed a repeated-measures, randomized, parallel-groups design. The protocol consisted of a baseline assessment, a recovery period (4, 24, or 48 hours), and a postrecovery assessment. The assessments were identical consisting of 4 sets of 10 repetition maximum (10RM) bicep curls and 4 sets of 10RM leg extensions to failure. Recovery was quantified as the number of total repetitions completed in the postrecovery bout. Fatigue was quantified as the number of repetitions completed set to set within the session. For analysis, we set the level of significance at p ≤ 0.05. No sex differences in performance recovery were observed across any of the investigated time periods for either exercise modality. Regarding fatigue, significant effects were observed for set (p < 0.001) and sex (p = 0.031) for bicep curls. Repetitions dropped in later sets, and females generally completed a greater number of repetitions than males (8.8 ± 0.5 vs. 7.2 ± 0.5). For leg extension, a significant sex × set interaction was observed (p = 0.003), but post hoc tests revealed these sex differences as marginal. Our results suggest that in dynamic bicep curls and leg extensions, other factors unrelated to sex may be more impactful on performance recovery. To optimize an athlete's desired adaptations, it may be more important to consider other variables unrelated to sex such as volume, perceived exertion, and training history when formulating training prescriptions for single-joint exercises. [ABSTRACT FROM AUTHOR]

We carried out a prospective case study in a high-level amateur natural male bodybuilder throughout preparation for 4 competitions and during the ensuing postcontest recovery period. Laboratory testing was conducted monthly over a 1-year period, which included the following assessments: B-mode ultrasound evaluation of muscle thickness (MT), multifrequency bioelectrical impedance analysis, blood pressure and heart rate assessment, resting metabolic rate via indirect calorimetry, skinfold testing, vertical jump height, isometric lowerbody strength testing, and a 3-factor eating questionnaire. Blood work (including testosterone, thyroid hormone, sex hormone binding globulin, glomerular filtration rate, blood urea nitrogen, aspartate aminotransferase, alanine aminotransferase, white blood count, albumin to globulin ratio, and lipoprotein A) was obtained separately from an outside laboratory at 4 time points. We also assessed the effectiveness of a carbohydrate (carb) deplete and carb load peaking strategy employed immediately before competition. The subject employed a high-volume, high-frequency, whole-body training program throughout the study period. Average daily nutritional intakes ranged from 1,953 to 3,415 kcal: 104-386 g carb; 253-263 g protein, and; 57-95 g lipid. Body fat was reduced to very low levels (~5%) immediately before competition, but this corresponded with a loss of lean mass. Alterations in metabolism, hormonal status, explosive strength, and psychological aspects of eating were observed during precontest preparation; however, all of these variables recovered quickly postcompetition. The implementation of a carb depleteand carb load peaking strategy acutely increased MT and thus may be a viable precontest approach to maximize muscular aesthetics. [ABSTRACT FROM AUTHOR]

Physique competitors focus on optimizing body composition through maximizing muscle mass and loss of body fat. Competitors frequently experiment with various methodologies purported to improve body composition, but often, there is a lack of evidence on their efficacy. Emerging evidence suggests that intermittent energy restriction (IER) methodologies such as refeeds and diet breaks may offer various benefits to competitors by improving fat loss efficiency, lean body mass retention, and attenuating metabolic adaptation to weight loss. This review examines these methodologies and the evidence for their efficacy and proposes practical ways to implement IER that may benefit physique competitors. [ABSTRACT FROM AUTHOR]

This prospective case study evaluated an experienced female figure competitor during contest preparation, 2 competitions, and a recovery period. Twelve laboratory sessions were conducted over 8 months. At each visit, body composition was assessed by 4-compartment model, resting metabolic rate (RMR) by indirect calorimetry, and neuromuscular performance by peak force and rate of force development (RFD) on a mechanized squat device. Caloric intake ranged from 965 to 1,610 kcal·d (16.1-24.8 kcal·kg·BM; 18.2-31.1 kcal·kg·FFM), with varying macronutrient intakes (CHO: 0.3-4.8 g·kg; PRO: 1.7-3.0 g·kg; and FAT: 0.2-0.5 g·kg). Body fat was reduced from 20.3 to 12.2% before the first competition and declined to 11.6% before the second competition. Fat-free mass increased by 2.1% before the first competition and peaked at 4.6% above baseline in the recovery period. Resting metabolic rate decreased from 1,345 kcal·d at baseline to a low value of 1,119 kcal·d between competitions. By the end of recovery, RMR increased to 1,435 kcal·d. Concentric and eccentric peak forces declined by up to 19% before the first competition, experienced perturbations in the inter-competition and recovery periods, and remained 5-8% below baseline at study termination. Similarly, RFD decreased by up to 57% before the first competition, was partially recovered, but remained 39% lower than baseline at study termination. Despite favorable body composition changes, neuromuscular performance was impaired during and after the competitive season in an experienced female physique competitor. [ABSTRACT FROM AUTHOR]

Twenty young women (20.3 + 1.5 years, 164 + 6 cm, 68.7 + 13.8 kg) without prior structured resistance training experience were recruited for this study. Body composition (BodPod), compartmental water (Bioelectrical Impedance), 7-site skinfold, and arm and thigh cross-sectional area (CSA) were assessed before and after 8-week training. Performance testing consisted of vertical jump, 3-kg chest pass initial velocity, squat 1RM, and overhead press 1RM. After 2 weeks of familiarization training, subjects were matched for body composition and relative squat strength and randomly assigned to either a high-load (HL: n = 10; 4 sets of 5-7 repetitions) or moderate-load (ML: n = 10; 2 sets of 10-14 repetitions) group that completed 6-7 exercises per day performed to momentary muscular failure. Training was divided into 2 lower and one upper body training sessions per week performed on nonconsecutive days for 8 weeks. There were no statistically significant main effects for group or group x time interactions for any variable assessed. Both HL and ML resulted in similar significant increases in lean body mass (1.5 ± 0.83 kg), lean dry mass (1.32 ± 0.62 kg), thigh CSA (6.6 ± 5.6 cm), vertical jump (2.9 ± 3.2 cm), chest pass velocity (0.334 ± 1.67 m·s), back squat one repetition maximum (1RM) (22.5 ± 8.1 kg), and overhead press (3.0 ± 0.8 kg). High-load group and ML group also both resulted in significant decreases in percent body fat (1.3 ± 1.3%), total body water (0.73 ± 0.70 L), and intracellular water (0.43 ± 0.38 L). The results of this study indicate that both moderate-load and high-load training are effective at improving muscle growth, body composition, strength and power in untrained young women. [ABSTRACT FROM AUTHOR]

To compare the effects of a high versus a moderate training frequency on maximal strength and body composition. Twenty-eight young, healthy resistance-trained men were randomly assigned to either: 3x per week (3x; n = 16) or 6x per week (6x; n = 12). Dependent variables (DVs) assessed at baseline and after the 6-week training intervention included: squat 1 repetition maximum (SQ1RM), bench press 1RM (BP1RM), deadlift 1RM (DL1RM), powerlifting total (PLT), Wilk's coefficient (WC), fat-free mass (FFM), and fat mass. Data for each DV were analyzed using a 2 x 2 between-within factorial repeated-measures analysis of variance. There was a main effect for time (p < 0.001) for SQ1RM (3x: +16.8 kg; 6x: +16.7 kg), BP1RM (3x: +7.8 kg; 6x: +8.8 kg), DL1RM (3x: +19 kg; 6x: +21 kg), PLT (3x: +43.6 kg; 6x: +46.5 kg), WC (3x: +27; 6x: +27.1), and FFM (3x: +1.7 kg; 6x: +2.6 kg). There were no group x time interactions or main effects for group. The primary finding was that 6 weeks of resistance training led to significant increases in maximal strength and FFM. In addition, it seems that increased training frequency does not lead to additional strength improvements when volume and intensity are equated. High-frequency (6x per week) resistance training does not seem to offer additional strength and hypertrophy benefits over lower frequency (3x per week) when volume and intensity are equated. Coaches and practitioners can therefore expect similar increases in strength and lean body mass with both 3 and 6 weekly sessions. [ABSTRACT FROM AUTHOR]

The article presents information on a study on the electromyographic (EMG) activity of 3 core muscles during physical fitness exercises in healthy adults. The findings of the study revealed that lumbar multifidus EMG activity is greater in free weight exercises than ball/device exercises and is same during core stability as well as ball/device exercises.

Groups of amino acids, as well as individual amino acids, have been studied for their roles in protein balance, hormone secretion, immune function, or capacity to be converted to various anabolic or anticatabolic metabolites. Specific amino acids with extensive analysis include the essential amino acids, branched chain amino acids, arginine, taurine, glutamine, beta-alanine, and the leucine metabolite, beta-hydroxy-beta-methylbutyrate. The purpose of this article is to analyze the possible roles and practical applications of these amino acids in the regulation of body composition and performance in anaerobic and aerobic sports. [ABSTRACT FROM AUTHOR]

MIXED MARTIAL ARTS (MMA) IS AN EXCITING AND COMPLEX SPORT THAT COMBINES THE TECHNIQUES OF BOXING, MUAY THAI KICKBOXING, AND VARIOUS GRAPPLING DISCIPLINES SUCH AS GRECO-ROMAN WRESTLING, FREESTYLE WRESTLING, AND BRAZILIAN JIU-JITSU. MMA IS A PHYSIOLOGICALLY DEMANDING SPORT. IT CAN POTENTIALLY CHALLENGE AND TAX ALL OF THE ENERGY SYSTEMS, AND THE POSSIBILITY OF OVERREACHING/OVERTRAINING IS A CONCERN. TO DATE, THERE IS LIMITED PEER-REVIEWED RESEARCH EXAMINING THE OPTIMAL TRAINING METHODS FOR AN ATHLETE COMPETING IN MMA. THE PURPOSE OF THIS REVIEW IS TO DISCUSS SOME OF THE AVAILABLE PEER-REVIEWED RESEARCH SURROUNDING THIS SPORT AND PROVIDE GENERAL CONSIDERATIONS FOR THE STRENGTH AND CONDITIONING SPECIALISTS. [ABSTRACT FROM AUTHOR]

The article reports on the results of research which was conducted to evaluate early-phase adaptations seen in response to to a split-body, linear periodization resistance training program used with college-aged and middle-aged men. Researchers found that that performing the training program for 8 weeks significantly increased bench press and leg press repetition maximums, and lean mass in college aged and middle aged men and that middle aged men who participated lost significantly more fat.

The acute response of IGF-1 to resistance exercise remains unclear. Most studies have shown no change in IGF-1 during or immediately following an acute bout of resistance exercise, whereas a few studies have shown acute elevations during and following resistance exercise. To determine the serum free IGF-1 response to an acute bout of intense, lower body resistance exercise. Ten healthy and physically active males (21±2.4yrs, 83±11.2kg, 176.8±7.7cm) engaged in an acute bout of lower body RE which consisted of four sets of both leg press and leg extension at 80% 1RM to failure. Rest periods between sets and exercises were approximately 150 seconds. Immediately prior to the resistance exercise bout, but following an 8-12 hour fast, participants underwent an initial/baseline blood draw. Blood was also obtained immediately, 30 minutes, two and six hours after the resistance exercise bout. Serum free- IGF-1 was analyzed via ELISA [Active® Bioactive ELISA by Diagnostic Systems Laboratories Inc. (DSL-10-9400; Webster, TX)]. A one-way ANOVA with repeated measures was utilized to analyze the data. Following the ANOVA, a series of paired-samples t-tests (one for each time point compared to baseline values) was conducted. Data are presented as means ± standard deviation utilizing ng/ml as the units of measurement. Baseline free IGF-1 = 1.2 ± 0.43 ng/ml. Following exercise, free IGF-1 concentrations were 1.6 ± 0.54; 1.5 ± 0.57; 1.4 ± 0.46; and 1.1 ± 0.53 ng/ml immediately post, 30 minutes, 2 hrs, and 6 hours post exercise, respectively. The ANOVA analysis indicated a significant difference across time for IGF-1 (p < .001). Subsequent paired-samples t-tests revealed a significant difference between the baseline and immediate post-resistance exercise IGF-1 levels (p = .001). Statistical trends were observed between baseline and 30 minutes post-exercise (p = .053) and baseline and 2 hours post-exercise (p = .052). An acute bout of lower-body resistance exercise in which each set is performed to failure significantly increases serum IGF-1 levels. The findings from the present study support those from other studies but are in contrast to others. Possible differences accounting for the discrepancies of the acute IGF-1 response to resistance exercise include training to failure on each set, rest periods between sets, exercise selection, or other variables. More investigations involving the response of IGF-1 to intense resistance exercise are needed to further elucidate the responses of this anabolic hormone. Resistance training improves muscular strength, muscular endurance, and increases lean body mass. Serum IGF-1, which increases in response to intense resistance exercise, may be (at least in part) responsible for some of these functional and physical adaptations in skeletal muscle. [ABSTRACT FROM AUTHOR]

The backgrounds of strength and conditioning coaches employed by Division I athletic programs are diverse. The diversity of the backgrounds can be described along a multitude of variables including: educational background, professional certifications, physical size and fitness, and competitive playing experiences, to name a few. Though research has not yet addressed this matter directly, it is possible that the background and characteristics of strength and conditioning coaches may bias professional assessment of prospective hires. Determine the presence of biases within a large sample of collegiate strength and conditioning coaches with respect to the relative importance of education, certifications, physical attributes, and playing experience. It is predicted that coaches will have biases that favor the qualities found in a coach that most closely resembles their own personal characteristics. The design of the study utilized electronic mail recruitment of strength and conditioning coaches at all Division I athletic programs. One hundred fifty-six (34 female, 122 male, mean age = 33 years) full-time strength and conditioning coaches at NCAA Division 1 universities responded to the online questionnaire. Items related to education, professional certifications, playing experience, coaching experience, body composition, and importance of background on effectiveness as a professional were included. Analyses utilizing ANOVA and t-tests revealed several significant findings in line with the research hypothesis. Specifically, strength and conditioning coaches possessing CSCS certification indicated this characteristic is more essential than those coaches without that certification (p < 0.05; ES = 1.17). Coaches with degrees in the exercise science field indicated this characteristic is more essential than coaches trained in fields outside of exercise science (p < 0.05; ES = 0.86). Coaches with collegiate playing experience indicated that such experience is more essential than coaches without collegiate playing experience (p < 0.05; ES = 0.59). Lastly, coaches describing themselves as highly muscular indicated that being physically larger was more essential for a coach than those describing themselves as less muscular (p < 0.05; ES = 1.00). These results generally confirm the hypothesis that strength and conditioning professionals generally perceive their personal background to be more essential for effectiveness as a coach than are background characteristics they do not personally possess. While these findings are not surprising given the reality that our life experiences shape our perceptions, this work does confirm the perspective that many strength and conditioning professionals view their path to professional achievement as the most appropriate. This study indicates that aspiring young professionals should be fully aware that the professional opinions provided to them by current strength and conditioning coaches may well be biased. It is expected that biases suggesting that being physically large in stature and having high level athletic experience will be diminished over time as the field evolves and moves away from many existing stereotypes. Aspiring strength and conditioning coaches are encouraged to seek out all available means and all available professional counsel to improve their employment profile and enhance their candidacy for positions within the field. [ABSTRACT FROM AUTHOR]

The growing public health burden associated with insufficient physical activity has resulted in the development of numerous health initiatives and products aimed at stabilizing and reversing the negative trends reported in epidemiological literature. A relatively novel product that has only recently made its way to the market are wearable weights. These products are designed to be worn on the lower legs and arms along with regular clothing as a means to increase caloric expenditure. However, no research to date has tested the efficacy of this product. Compare the physiological and psychological responses within bouts of aerobic exercise that vary on intensity and the presence of wearable weights. Thirteen (8 female, 5 male, mean age = 24 years, mean BMI = 24) healthy volunteers were tested for aerobic fitness on a treadmill to determine o2max (mean = 44 ml × kg-1 × min-1). Participants then completed eight 30-minute walking trials on a treadmill while oxygen consumption (o2), heart rate (HR), and ratings of perceived exertion (RPE) were monitored while walking at different speeds and with varying combination of upper and lower body wearable weights. The design included two intensities (slow walking and brisk walking) and four conditions (no weights, arm weights, leg weights, and arm and leg weights) for a total of eight experimental trials. Data were analyzed using ANOVA and pairwise comparisons. Analyses revealed a that o2 was significantly lower without the wearable weights in comparison to wearing both upper and lower weights in the slow walk trial (p < 0.001; ES = 0.97) and trended towards significance in the brisk walk trial (p < 0.09; ES = 0.37). HR did not differ across trials for the slow or brisk walk trials (p > 0.05). RPE was significantly elevated while wearing upper and lower weights in the brisk walk trial (p < 0.05; ES = 0.55), but not in the slow walk trial (p > 0.05). Findings suggest that exercising while using wearable weights increases energy expenditure, has no impact on HR, and impacts RPE only during the faster walking trials. The increased energy expenditure associated with wearing the weights was modest, but the increases within the slower walking trial occurred without increased RPE. This finding suggests that physical activity associated with daily living could be enhanced through the wearing of weights that can be worn under clothing without increasing perceptions of effort. In contrast, findings relative to brisk walking suggest that any beneficial increase in energy expenditure is potentially offset by significantly increased effort. [ABSTRACT FROM AUTHOR]