Changes in hormonal profiles during competition preparation in physique athletes.

PURPOSE: Physique athletes engage in rigorous competition preparation involving intense energy restriction and physical training to enhance muscle definition. This study investigates hormonal changes and their physiological and performance impacts during such preparation. METHODS: Participants included female (10 competing (COMP) and 10 non-dieting controls (CTRL)) and male (13 COMP and 10 CTRL) physique athletes. COMP participants were tested 23 weeks before (PRE), one week before (MID), and 23 weeks after the competition (POST). Non-dieting CTRL participants were tested at similar intervals. Measurements included body composition (DXA), muscle cross-sectional area (ultrasound), energy availability (EA) derived by subtracting exercise energy expenditure (EEE) from energy intake (EI) and dividing by fat-free mass (FFM), muscle strength, and various serum hormone concentrations (ACTH, cortisol, estradiol, FSH, IGF-1, IGFBP-3, insulin, and free and total testosterone and SHBG). RESULTS: During the diet, EA (p < 0.001), IGF-1 (p < 0.001), IGFBP-3 (p < 0.01), and absolute muscle strength (p < 0.01-0.001) decreased significantly in both sexes in COMP. Decreases in IGF-1 were also associated with higher loss in FFM. In males, testosterone (p < 0.01) and free testosterone (p < 0.05) decreased, while SHBG (p < 0.001) and cortisol (p < 0.05) increased. Insulin decreased significantly only in males (p < 0.001). Mood disturbances, particularly increased fatigue in males (p < 0.05), highlighted the psychological strain of competition preparation. All these changes were restored by increased EA during the post-competition recovery period. CONCLUSION: Significant reductions in IGF-1 and IGFBP-3 during competition preparation may serve as biomarkers for monitoring physiological stress. This study offers valuable insights into hormonal changes, muscle strength, and mood state during energy-restricted intense training.

Similar muscle hypertrophy following eight weeks of resistance training to momentary muscular failure or with repetitions-in-reserve in resistance-trained individuals.

This study examined the influence of resistance training (RT) proximity-to-failure, determined by repetitions-in-reserve (RIR), on quadriceps hypertrophy and neuromuscular fatigue. Resistance-trained males (n = 12) and females (n = 6) completed an 8-week intervention involving two RT sessions per week. Lower limbs were randomised to perform the leg press and leg extension exercises either to i) momentary muscular failure (FAIL), or ii) a perceived 2-RIR and 1-RIR, respectively (RIR). Muscle thickness of the quadriceps [rectus femoris (RF) and vastus lateralis (VL)] and acute neuromuscular fatigue (i.e., repetition and lifting velocity loss) were assessed. Data was analysed with Bayesian linear mixed-effect models. Increases in quadriceps thickness (average of RF and VL) from pre- to post-intervention were similar for FAIL [0.181 cm (HDI: 0.119 to 0.243)] and RIR [0.182 cm (HDI: 0.115 to 0.247)]. Between-protocol differences in RF thickness slightly favoured RIR [-0.036 cm (HDI: -0.113 to 0.047)], but VL thickness slightly favoured FAIL [0.033 cm (HDI: -0.046 to 0.116)]. Mean volume was similar across the RT intervention between FAIL and RIR. Lifting velocity and repetition loss were consistently greater for FAIL versus RIR, with the magnitude of difference influenced by the exercise and the stage of the RT intervention.

Terminating RT sets with a close proximity-to-failure (e.g., 1- to 2-RIR) can be sufficient to promote similar hypertrophy of the quadriceps as reaching momentary muscular failure in resistance-trained individuals over eight weeks, but the overall influence of proximity-to-failure on muscle-specific hypertrophy may also depend on other factors (e.g., exercise selection, order, and subsequent musculature targeted).Due to high repetition loss (from the first to final set) when sets are terminated at momentary muscular failure, performing RT with 1- to 2-RIR allows for similar volume load and repetition volume accumulation as reaching momentary muscular failure across eight weeks, possibly influencing the overall RT stimulus achieved.Performing RT to momentary muscular failure consistently induces higher levels of acute neuromuscular fatigue versus RT performed with 1- to 2-RIR; however, improved fatigue resistance overtime may attenuate acute neuromuscular fatigue and subsequent repetition loss (but may depend on the exercise performed).

A Survey of Resistance Training Practices Among Physique Competitors During Peak Week.

ABSTRACT: Homer, KA, Cross, MR, and Helms, ER. A survey of resistance training practices among physique competitors during peak week. J Strength Cond Res XX(X): 000-000, 2024-Physique athletes are ranked by their on-stage presentation of muscle size, proportionality, and leanness. To acutely maximize muscle size, competitors manipulate resistance training (RT) variables in the days before the contest, commonly referred to as peak week (PW). Resistance training manipulations during PW may act synergistically with nutrition strategies such as carbohydrate loading. However, because little information exists on changes made to RT during PW, the purpose of this research was to determine the current practices of physique athletes and whether competitor characteristics were predictive of the RT variables manipulated. A total of 104 responses to the RT section of a survey on PW nutrition and training were analyzed through a series of multiple logistic regression models to examine the relationship between RT manipulations and competitor characteristics. Furthermore, to determine the magnitude of differences between PW and the week before PW (WBPW) for these variables, a McNemar-Bowker test, paired t-tests, and Wilcoxon signed-rank tests were conducted for nominal, continuous, and discrete outcomes, respectively. For all statistical analyses, p <0.05 was deemed significant. Competitors generally adjusted RT in a variety of ways, where proximity-to-failure was the most frequently manipulated and training frequency was the least; however, no competitor characteristic predicted any of the RT variables manipulated. Within those who manipulated RT variables during PW, frequency, volume, and intensity decreased while repetition ranges of compound exercises increased, empirically confirming that competitors seek to reduce training stress during PW. Such findings can be incorporated in future experimental designs examining the efficacy of peaking strategies to enhance the generalizability of results.

Accuracy of Intraset Repetitions-in-Reserve Predictions During the Bench Press Exercise in Resistance-Trained Male and Female Subjects.

ABSTRACT: Refalo, MC, Remmert, JF, Pelland, JC, Robinson, ZP, Zourdos, MC, Hamilton, DL, Fyfe, JJ, and Helms, ER. Accuracy of intraset repetitions-in-reserve predictions during the bench press exercise in resistance-trained male and female subjects. J Strength Cond Res 38(3): e78-e85, 2024-This study assessed the accuracy of intraset repetitions-in-reserve (RIR) predictions to provide evidence for the efficacy of RIR prescription as a set termination method to inform proximity to failure during resistance training (RT). Twenty-four resistance trained male ( n = 12) and female ( n = 12) subjects completed 2 experimental sessions involving 2 sets performed to momentary muscular failure (barbell bench press exercise) with 75% of 1 repetition maximum (1RM), whereby subjects verbally indicated when they perceived to had reached either 1 RIR or 3 RIR. The difference between the predicted RIR and the actual RIR was defined as the "RIR accuracy" and was quantified as both raw (i.e., direction of error) and absolute (i.e., magnitude of error) values. High raw and absolute mean RIR accuracy (-0.17 ± 1.00 and 0.65 ± 0.78 repetitions, respectively) for 1-RIR and 3-RIR predictions were observed (including all sets and sessions completed). We identified statistical equivalence (equivalence range of ±1 repetition, thus no level of statistical significance was set) in raw and absolute RIR accuracy between (a) 1-RIR and 3-RIR predictions, (b) set 1 and set 2, and (c) session 1 and session 2. No evidence of a relationship was found between RIR accuracy and biological sex, years of RT experience, or relative bench press strength. Overall, resistance-trained individuals are capable of high absolute RIR accuracy when predicting 1 and 3 RIR on the barbell bench press exercise, with a minor tendency for underprediction. Thus, RIR prescriptions may be used in research and practice to inform the proximity to failure achieved upon set termination.

The general nutrition practices of competitive powerlifters vary by competitive calibre and sex, weight, and age class.

PURPOSE: To characterise self-reported nutrition practices and beliefs of powerlifters. METHODS: Actively competing male (n = 240) and female (n = 65) powerlifters completed a cross-sectional online survey of self-reported nutrition practices across the competitive cycle, within specific competitive phases, and hard and easy training days. Data are presented as number (n) and percentage (%) of all powerlifters practicing a given strategy followed by a % of responses reporting various practices or beliefs within this strategy. Differences in categorical sub-groups (sex, age, and weight class; and competitive calibre) were analysed with a chi-square test and denoted where significant (p ≤ 0.05). RESULTS: Most powerlifters reported following a specific diet long-term (n = 203, 66.6%) of which If It Fits Your Macros (IIFYM)/flexible dieting was most common (n = 159, 78.3%). Over half reported introducing a special diet for a competitive phase (n = 162, 53.1%), of which IIFYM/flexible dieting was most followed for competition preparation (n = 80, 63%) and off-season (n = 48, 71.6%). Compared to normal dietary intake, most reported eating more on harder training days (n = 219, 71.8%) and refraining from eating less on easier training days (n = 186, 61%). CONCLUSIONS: IIFYM/flexible dieting is commonly followed by powerlifters to support performance and body composition goals. Females seemed to report more often restricting energy and dieting for body composition reasons than males. Powerlifters tailor their energy intake on harder training days to the higher training demands but refrain from reducing energy intake on rest/easier training days.

Velocity loss is a flawed method for monitoring and prescribing resistance training volume with a free-weight back squat exercise.

PURPOSE: The aim of this study was to examine the goodness of fit, prediction accuracy, and stability of general and individual relationships between velocity loss and the percentage of completed repetitions out of maximum possible (VL-%repetitions) in the free-weight back squat exercise. The effects of sex, training status and history, as well as personality traits, on the goodness of fit and the accuracy of these relationships were also investigated. METHODS: Forty-six resistance-trained people (15 females and 31 males) performed a one-repetition maximum (1RM) test, and two repetitions to failure (RTF) tests, 72 h apart. RTF tests were performed with 70, 80, and 90% of 1RM with 10 min inter-set rest. RESULTS: The findings question the utility of using general and individual VL-%repetitions relationships to prescribe training volume with free-weight back squats as (1) the agreement in the %repetitions completed until reaching a given velocity loss threshold across two consecutive testing sessions was unacceptable, regardless of the load used; and (2) the ability of general and individual VL-%repetitions relationships to predict %repetitions in a subsequent testing session were poor (absolute errors > 10%). Sex, training status and history, and personality traits did not affect the goodness of fit of general and individual VL-%repetitions relationships or their prediction accuracy, suggesting potential generalisability of those findings among resistance-trained populations. CONCLUSIONS: VL-%repetitions relationships do not seem to provide any additional benefits compared to costless, traditional methods and hence should not be used for monitoring and prescribing resistance training with a free-weight back squat exercise.

Individual Muscle Contributions to the Acceleration of the Center of Mass During the Barbell Back Squat in Trained Female Subjects.

ABSTRACT: Goodman, WW, Helms, E, and Graham, DF. Individual muscle contributions to the acceleration of the center of mass during the barbell back squat in trained female subjects. J Strength Cond Res 37(10): 1947-1954, 2023-The squat is used to enhance performance and rehabilitate the lower body. However, muscle forces and how muscles accelerate the center of mass (CoM) are not well understood. The purpose was to determine how lower extremity muscles contribute to the vertical acceleration of the CoM when squatting to parallel using 85% one-repetition maximum. Thirteen female subjects performed squats in a randomized fashion. Musculoskeletal modeling was used to obtain muscle forces and muscle-induced accelerations. The vasti, soleus, and gluteus maximus generated the largest upward accelerations of the CoM, whereas the muscles that produced the largest downward acceleration about the CoM were the hamstrings, iliopsoas, adductors, and tibialis anterior. Our findings indicate that a muscle's function is task and posture specific. That is, muscle function depends on both joint position and how an individual is interacting with the environment.

Range of Motion Predicts Performance in National-Level New Zealand Male Powerlifters.

ABSTRACT: Spence, AJ, Helms, ER, Sousa, CA, and McGuigan, MR. Range of motion predicts performance in National-level New Zealand male powerlifters. J Strength Cond Res 37(1): 123-128, 2023-Previous research established that male powerlifters have less range of motion (ROM) in several movements about the shoulder and hip compared with sedentary male subjects. It is unclear if these differences in ROM are related to strength, training type, and years of training experience or if individuals with less ROM have a better propensity to gain strength. The purpose of this study was to compare strength and ROM in male powerlifters and recreationally strength-trained male subjects and to determine if ROM would be an effective predictor of strength in these groups. Twelve powerlifters and 12 recreationally strength-trained control subjects completed 1 repetition maximum (1RM) squat and bench press testing. In a subsequent session, active ROM was measured, and velocity data were collected during submaximal squat repetitions. There was no significant difference (p > 0.05) between the groups for age, height, body mass, training experience, and training frequency. Powerlifters had significantly greater (p ≤ 0.05) training duration and absolute squat and bench press 1RM. Powerlifters had significantly less shoulder extension and horizontal abduction, and hip flexion, extension, and adduction than recreationally strength-trained men. Significant negative relationships were found between 2-lift Wilks score (body mass relative strength) and shoulder extension and horizontal abduction, as well as hip flexion and extension. In powerlifters, significant negative relationships were found between competition Wilks score, shoulder extension, and hip flexion. Because these relationships correspond to the bottom position of the squat and bench press, it may be best to ensure that shoulder extension and hip flexion remain sufficient to achieve competition depth.

Towards an improved understanding of proximity-to-failure in resistance training and its influence on skeletal muscle hypertrophy, neuromuscular fatigue, muscle damage, and perceived discomfort: A scoping review.

While proximity-to-failure is considered an important resistance training (RT) prescription variable, its influence on physiological adaptations and short-term responses to RT is uncertain. Given the ambiguity in the literature, a scoping review was undertaken to summarise evidence for the influence of proximity-to-failure on muscle hypertrophy, neuromuscular fatigue, muscle damage and perceived discomfort. Literature searching was performed according to PRISMA-ScR guidelines and identified three themes of studies comparing either: i) RT performed to momentary muscular failure versus non-failure, ii) RT performed to set failure (defined as anything other than momentary muscular failure) versus non-failure, and iii) RT performed to different velocity loss thresholds. The findings highlight that no consensus definition for "failure" exists in the literature, and the proximity-to-failure achieved in "non-failure" conditions is often ambiguous and variable across studies. This poses challenges when deriving practical recommendations for manipulating proximity-to-failure in RT to achieve desired outcomes. Based on the limited available evidence, RT to set failure is likely not superior to non-failure RT for inducing muscle hypertrophy, but may exacerbate neuromuscular fatigue, muscle damage, and post-set perceived discomfort versus non-failure RT. Together, these factors may impair post-exercise recovery and subsequent performance, and may also negatively influence long-term adherence to RT.KEY POINTS This scoping review identified three broad themes of studies investigating proximity-to-failure in RT, based on the specific definition of set failure used (and therefore the research question being examined), to improve the validity of study comparisons and interpretations.There is no consensus definition for set failure in RT, and the proximity-to-failure achieved during non-failure RT is often unclear and varies both within and between studies, which together poses challenges when interpreting study findings and deriving practical recommendations regarding the influence of RT proximity-to-failure on muscle hypertrophy and other short-term responses.Based on the limited available evidence, performing RT to set failure is likely not superior to non-failure RT to maximise muscle hypertrophy, but the optimal proximity to failure in RT for muscle hypertrophy is unclear and may be moderated by other RT variables (e.g., load, volume-load). Also, RT performed to set failure likely induces greater neuromuscular fatigue, muscle damage, and perceived discomfort than non-failure RT, which may negatively influence RT performance, post-RT recovery, and long-term adherence.

Prevalence, Magnitude, and Methods of Weight Cutting Used by World Class Powerlifters.

ABSTRACT: Kwan, K and Helms, E. Prevalence, magnitude, and methods of weight cutting used by world class powerlifters. J Strength Cond Res 36(4): 998-1002, 2022-Powerlifters compete in the squat, bench press, and deadlift, with winners determined by the highest 3-lift total in each weight class. As a weight class-based sport, athletes often compete in classes lower than their habitual weight, using various strategies to make weight. This study's purpose was to examine weight cutting prevalence, magnitude, and methods among 42 male and 22 female powerlifters (25 ± 8 years old; 4 ± 2.2 years of competitive experience) competing at the 2018 International Powerlifting Federation classic world championship. The lifters, 83% of whom cut weight losing an average 2.9 ± 4.3% of body mass, completed a previously validated weight cutting questionnaire. The most frequently used weight cutting methods were gradual dieting (42.18%, 31.25%), fluid restriction after fluid loading (32.8%, 34.4%), restricting fluid ingestion without fluid loading (23.4%, 9.4%), fasting (15.6%, 18.7%), increased activity (9.4%, 24.4%), laxatives (9.4%, 18.7%), sauna (7.8%, 6.3%), diuretics (7.8%, 6.3%), skipping meals (4.7%, 21.9%), and wearing rubber suits (1.6%, 2.6%). Most lifters experienced negative changes in psychological state, with only 9% reporting never experiencing any negative effect on psychological state across the 5 states measured. Lifters reported experiencing fatigue (15.6%, 45.3%), anger (3.2%, 26.6%), feelings of isolation (4.7%, 12.5%), and anxiety (14.1%, 35.95%), and 11 of the 12 lifters who reported a perceived decrement in training performance performed weight cutting. Both weight cutting methods and negative psychological changes experienced were reported as always, sometimes. Therefore, it is vital to provide specific recommendations based on scientific research to improve the efficacy and safety of making weight while minimizing performance decrements.

Stretching Practices of International Powerlifting Federation Unequipped Powerlifters.

ABSTRACT: Spence, A-J, Helms, ER, and McGuigan, MR. Stretching practices of International Powerlifting Federation unequipped powerlifters. J Strength Cond Res 36(12): 3456-3461, 2022-Stretching practices in powerlifters. The purpose of this study was to provide insight into the stretching practices of competitive powerlifters. Powerlifters ( n = 319) from 51 countries completed a self-reported online survey on stretching practices. Subjects had (mean ± SD , median, and interquartile range) 7.7 ± 6.1, 6, and 6 years of general resisting training, 4.4 ± 4.5, 3, and 3 years of strength specific training, and been competing in powerlifting for 3.0 ± 3.7, 2, and 2 years with the average Wilks score being 366.4 ± 52.2, 365, and 60. Analysis by sex and competitive standard was conducted. More than 50% (52.4%) of subjects ( n = 167) reported stretching; of those, 84.4% performed static stretches, and 90.4% performed dynamic stretches. Stretching was performed before resistance training by 77.8%, after resistance training by 43.7%, and 53.9% stretched independent of resistance training. Powerlifters who performed static stretches before training did an average of 6.72 ± 10.31, 5, and 8 repetitions per stretch and held those stretches for an average of 30.8 ± 31.4, 20, and 15 seconds; 90.1% also performed dynamic stretches. Powerlifters who performed static stretches after or independent of training did an average of 4.1 ± 4.2, 2, and 9 repetitions per stretch and held those stretches for an average of 42.9 ± 30.8, 30, and 33 seconds. The majority of powerlifters (66.9%) programmed stretching themselves, whereas only 10.2% had stretching programmed by their coach. These data will inform athletes and coaches about the prevalence and characteristics of current stretching practices in powerlifters.

Effect of Set-Structure on Upper-Body Muscular Hypertrophy and Performance in Recreationally-Trained Male and Female.

ABSTRACT: Davies, TB, Halaki, M, Orr, R, Mitchell, L, Helms, ER, Clarke, J, and Hackett, DA. Effect of set structure on upper-body muscular hypertrophy and performance in recreationally trained men and women. J Strength Cond Res 36(8): 2176-2185, 2022-This study explored the effect of volume-equated traditional-set and cluster-set structures on muscular hypertrophy and performance after high-load resistance training manipulating the bench press exercise. Twenty-one recreationally trained subjects (12 men and 9 women) performed a 3-week familiarization phase and were then randomized into one of two 8-week upper-body and lower-body split programs occurring over 3 and then progressing to 4 sessions per week. Subjects performed 4 sets of 5 repetitions at 85% one repetition maximum (1RM) using a traditional-set structure (TRAD, n = 10), which involved 5 minutes of interset rest only, or a cluster-set structure, which included 30-second inter-repetition rest and 3 minutes of interset rest (CLUS, n = 11). A 1RM bench press, repetitions to failure at 70% 1RM, regional muscle thickness, and dual-energy x-ray absorptiometry were used to estimate changes in muscular strength, local muscular endurance, regional muscular hypertrophy, and body composition, respectively. Velocity loss was assessed using a linear position transducer at the intervention midpoint. TRAD demonstrated a significantly greater velocity loss magnitude (g = 1.50) and muscle thickness of the proximal pectoralis major (g = -0.34) compared with CLUS. There were no significant differences between groups for the remaining outcomes, although a small effect size favoring TRAD was observed for the middle region of the pectoralis major (g = -0.25). It seems that the greater velocity losses during sets observed in traditional-set compared with cluster-set structures may promote superior muscular hypertrophy within specific regions of the pectoralis major in recreationally trained subjects.

Range of Motion Is Not Reduced in National-Level New Zealand Female Powerlifters.

ABSTRACT: Spence, A-J, Helms, ER, and McGuigan, MR. Range of motion is not reduced in national-level New Zealand female powerlifters. J Strength Cond Res 35(10): 2737-2741, 2021-Some research suggests male powerlifters have less range of motion (ROM) in several directions about the shoulder and hip compared with sedentary men. In addition, those differences may be more pronounced in groups with higher strength levels and more years of experience. However, there is no information on ROM in female powerlifters. The purpose of this study was to evaluate single-joint ROM in competitive female powerlifters and determine whether single-joint ROM would be an effective predictor of strength in this population. Twelve female powerlifters and 12 female recreationally trained age-matched controls attended one testing session. Subjects reported their years of training experience, frequency, and average duration of training sessions. Active ROM measurements were collected at the shoulder, hip, and knee, using goniometry. There was no significant difference (p > 0.05) between groups for age, height, body mass, training experience, and training frequency. Powerlifters reported significantly greater (p ≤ 0.05) training durations than recreationally trained women. Powerlifters had significantly greater shoulder horizontal abduction on the right side (p = 0.022, g = 0.97), but no other ranges were significantly different between groups, and no ranges were significantly related to strength. Powerlifting does not seem to affect shoulder, hip, or knee ROM differently than recreational resistance training in women. Single-joint ROM was not an effective predictor of strength in female powerlifters.

Effect of Set-Structure on Upper-Body Muscular Hypertrophy and Performance in Recreationally-Trained Male and Female.

ABSTRACT: Davies, TB, Halaki, M, Orr, R, Mitchell, L, Helms, ER, Clarke, J, and Hackett, DA. Effect of set structure on upper-body muscular hypertrophy and performance in recreationally trained men and women. J Strength Cond Res XX(X): 000-000, 2021-This study explored the effect of volume-equated traditional-set and cluster-set structures on muscular hypertrophy and performance after high-load resistance training manipulating the bench press exercise. Twenty-one recreationally trained subjects (12 men and 9 women) performed a 3-week familiarization phase and were then randomized into one of two 8-week upper-body and lower-body split programs occurring over 3 and then progressing to 4 sessions per week. Subjects performed 4 sets of 5 repetitions at 85% one repetition maximum (1RM) using a traditional-set structure (TRAD, n = 10), which involved 5 minutes of interset rest only, or a cluster-set structure, which included 30-second inter-repetition rest and 3 minutes of interset rest (CLUS, n = 11). A 1RM bench press, repetitions to failure at 70% 1RM, regional muscle thickness, and dual-energy x-ray absorptiometry were used to estimate changes in muscular strength, local muscular endurance, regional muscular hypertrophy, and body composition, respectively. Velocity loss was assessed using a linear position transducer at the intervention midpoint. TRAD demonstrated a significantly greater velocity loss magnitude (g = 1.50) and muscle thickness of the proximal pectoralis major (g = -0.34) compared with CLUS. There were no significant differences between groups for the remaining outcomes, although a small effect size favoring TRAD was observed for the middle region of the pectoralis major (g = -0.25). It seems that the greater velocity losses during sets observed in traditional-set compared with cluster-set structures may promote superior muscular hypertrophy within specific regions of the pectoralis major in recreationally trained subjects.

Rating of Perceived Exertion and Velocity Relationships Among Trained Males and Females in the Front Squat and Hexagonal Bar Deadlift.

ABSTRACT: Odgers, JB, Zourdos, MC, Helms, ER, Candow, DG, Dahlstrom, B, Bruno, P, and Sousa, CA. Rating of perceived exertion and velocity relationships among trained males and females in the front squat and hexagonal bar deadlift. J Strength Cond Res 35(2S): S23-S30, 2021-This study examined the accuracy of intraset rating of perceived exertion (RPE) to predict repetitions in reserve (RIR) during sets to failure at 80% of 1 repetition maximum (1RM) on the front squat and high-handle hexagonal bar deadlift (HHBD). Furthermore, the relationship between RPE and average concentric velocity (ACV) during the sets to failure was also determined. Fourteen males (29 ± 6 years, front squat relative 1RM: 1.78 ± 0.2 kg·kg-1, and HHBD relative 1RM: 3.0 ± 0.1 kg·kg-1) and 13 females (30 ± 5 years, front squat relative 1RM: 1.60 ± 0.2 kg·kg-1, and HHBD relative 1RM: 2.5 ± 0.3 kg·kg-1) visited the laboratory 3 times. The first visit tested 1RM on both exercises. During visits 2 and 3, which were performed in a counterbalanced order, subjects performed 4 sets to failure at 80% of 1RM for both exercises. During each set, subjects verbally indicated when they believed they were at "6" and "9" on the RIR-based RPE scale, and ACV was assessed during every repetition. The difference between the actual and predicted repetitions performed was recorded as the RPE difference (RPEDIFF). The RPEDIFF was significantly (p < 0.001) lower at the called 9 RPE versus the called 6 RPE in the front squat for males (9 RPE: 0.09 ± 0.19 versus 6 RPE: 0.71 ± 0.70) and females (9 RPE: 0.19 ± 0.36 versus 6 RPE: 0.86 ± 0.88) and in the HHBD for males (9 RPE: 0.25 ± 0.46 versus 6 RPE: 1.00 ± 1.12) and females (9 RPE: 0.21 ± 0.44 versus 6 RPE: 1.19 ± 1.16). Significant inverse relationships existed between RPE and ACV during both exercises (r = -0.98 to -1.00). These results indicate that well-trained males and females can gauge intraset RPE accurately during moderate repetition sets on the front squat and HHBD.

Proximity to Failure and Total Repetitions Performed in a Set Influences Accuracy of Intraset Repetitions in Reserve-Based Rating of Perceived Exertion.

ABSTRACT: Zourdos, MC, Goldsmith, JA, Helms, ER, Trepeck, C, Halle, JL, Mendez, KM, Cooke, DM, Haischer, MH, Sousa, CA, Klemp, A, and Byrnes, RK. Proximity to failure and total repetitions performed in a set influences accuracy of intraset repetitions in reserve-based rating of perceived exertion. J Strength Cond Res 35(2S): S158-S165, 2021-The aim of this study was to assess the accuracy of predicting repetitions in reserve (RIR) intraset using the RIR-based rating of perceived exertion (RPE) scale. Twenty-five men (age: 25.3 ± 3.3 years, body mass: 89.0 ± 14.7 kg, height: 174.69 ± 6.7 cm, and training age: 4.7 ± 3.2 years) reported to the laboratory. Subjects performed a 1 repetition maximum (1RM) squat followed by one set to failure at 70% of 1RM. During the 70% set, subjects verbally indicated when they believed they were at a 5RPE (5RIR), 7RPE (3RIR), or 9RPE (1RIR), and then continued to failure. The difference between actual repetitions performed and participant-predicted repetitions was calculated as the RIR difference (RIRDIFF). The average load used for the 70% set was 123.10 ± 24.25 kg and the average repetitions performed were 16 ± 4. The RIRDIFF was lower (RPEs were more accurate) closer to failure (RIRDIFF at 9RPE = 2.05 ± 1.73; RIRDIFF at 7RPE = 3.65 ± 2.46; and RIRDIFF at 5RPE = 5.15 ± 2.92 repetitions). There were significant relationships between total repetitions performed and RIRDIFF at 5RPE (r = 0.65, p = 0.001) and 7RPE (r = 0.56, p = 0.004), but not at 9RPE (r = 0.01, p = 0.97). Thus, being farther from failure and performing more repetitions in a set were associated with more inaccurate predictions. Furthermore, a multiple linear regression revealed that more repetitions performed per set was a significant predictor of RIR prediction inaccuracy at the called 5 (p = 0.003) and 7 (p = 0.011) RPEs, while training age (p > 0.05) was not predictive of rating accuracy. These data indicate RIR predictions are improved during low to moderate repetition sets and when there is close proximity to failure.

Interactions between different eating patterns on recurrent binge-eating behavior: A machine learning approach.

OBJECTIVE: Previous research has shown that certain eating patterns (rigid restraint, flexible restraint, intuitive eating) are differentially related to binge eating. However, despite the distinctiveness of these eating patterns, evidence suggests that they are not mutually exclusive. Using a machine learning-based decision tree classification analysis, we examined the interactions between different eating patterns in distinguishing recurrent (defined as ≥4 episodes the past month) from nonrecurrent binge eating. METHOD: Data were analyzed from 1,341 participants. Participants were classified as either with (n = 512) or without (n = 829) recurrent binge eating. RESULTS: Approximately 70% of participants could be accurately classified as with or without recurrent binge eating. Intuitive eating emerged as the most important classifier of recurrent binge eating, with 75% of those with above-average intuitive eating scores being classified without recurrent binge eating. Those with concurrently low intuitive eating and high dichotomous thinking scores were the group most likely to be classified with recurrent binge eating (84% incidence). Low intuitive eating scores were associated with low binge-eating classification rates only if both dichotomous thinking and rigid restraint scores were low (33% incidence). Low flexible restraint scores amplified the relationship between high rigid restraint and recurrent binge eating (81% incidence), and both a higher and lower BMI further interacted with these variables to increase recurrent binge-eating rates. CONCLUSION: Findings suggest that the presence versus absence of recurrent binge eating may be distinguished by the interaction among multiple eating patterns. Confirmatory studies are needed to test the interactive hypotheses generated by these exploratory analyses.

Changes in Bench Press Velocity and Power After 8 Weeks of High-Load Cluster- or Traditional-Set Structures.

Davies, TB, Halaki, M, Orr, R, Helms, ER, and Hackett, DA. Changes in bench press velocity and power after 8 weeks of high-load cluster- or traditional-set structures. J Strength Cond Res 34(10): 2734-2742, 2020-This study investigated the effects of high-load cluster- vs. traditional-set structures using the bench press on velocity and power. Twenty-one resistance-trained individuals (male = 12, female = 9) performed a 3-week familiarization block followed by randomization into 1 of 2 upper- and lower-body split training routines performed for 8 weeks. The bench press was the only exercise manipulated with subjects using either cluster-set (CLUS, n = 11) or traditional-set (TRAD, n = 10) structures during training sessions. Subjects performed 4 sets of 5 repetitions at 85% 1 repetition maximum (1RM) with CLUS having a 30-second inter-repetition, and 3-minute interset rest while TRAD had a 5-minute interset rest. A load-velocity profile of relative loads derived from a 1RM test was used to assess velocity and power (absolute and relative to body mass) on the bench press. Significant improvements over time were found across various loads ranging from 45 to 75% 1RM for absolute and relative peak power (p = 0.006-0.041), and mean power (p = 0.001-0.032). Significant decreases over time were found at 55% 1RM and 65% 1RM for peak velocity (p = 0.027 and p = 0.012, respectively) and mean velocity (p = 0.047 and p = 0.022, respectively). There were no significant group or group by time interactions found for all outcomes. Within the context of high-load resistance training, set structure seems to be of less importance for changes in bench press velocity and power provided there is an intention to lift with maximal concentric velocity.

The effects of eccentric phase duration on concentric outcomes in the back squat and bench press in well-trained males.

The velocity and magnitude in which the eccentric phase of an exercise is completed directly affects performance during the concentric phase. Therefore, the purpose of this research was to investigate the effects of eccentric phase duration on concentric outcomes at 60% and 80% of one-repetition maximum (1RM) in the squat and bench press. Sixteen college-aged, resistance-trained males completed 1RM testing, established normative eccentric durations, and performed fast (0.75 times normative) and slow (2.0 times normative) metronome-controlled eccentric duration repetitions. Outcome measures assessed during the concentric phase were: average concentric velocity (ACV), peak concentric velocity (PCV), rating of perceived exertion (RPE), range of motion (ROM), and barbell path. Eccentric duration was significantly and inversely correlated with ACV at 60% (r = -0.408, p = 0.004) and 80% (r = -0.477, p = 0.001) of 1RM squat. At 60% of 1RM squat, both fast and slow eccentric conditions produced greater (p < 0.001) PCV than normative duration with fast also producing greater PCV than slow (p = 0.044). Eccentric duration had no impact on RPE, ROM, or barbell path. Our results report for the first time that resistance-trained males performing a deliberately faster eccentric phase may enhance their own squat and bench press performance.

The High-Bar and Low-Bar Back-Squats: A Biomechanical Analysis.

Glassbrook, DJ, Brown, SR, Helms, ER, Duncan, S, and Storey, AG. The high-bar and low-bar back-squats: a biomechanical analysis. J Strength Cond Res 33(7S): S1-S18, 2019-No previous study has compared the joint angle and ground reaction force (vertical force [Fv]) differences between the high-bar back-squat (HBBS) and low-bar back-squat (LBBS) above 90% 1 repetition maximum (1RM). Six male powerlifters (POW) (height: 179.2 ± 7.8 cm; mass: 87.1 ± 8.0 kg; age: 21-33 years) of international level, 6 male Olympic weightlifters (OLY) (height: 176.7 ± 7.7 cm; mass: 83.1 ± 13 kg; age: 22-30 years) of national level, and 6 recreationally trained male athletes (height: 181.9 ± 8.7 cm; mass: 87.9 ± 15.3 kg; age: 23-33 years) performed the LBBS, HBBS, and both LBBS and HBBS (respectively) up to and including 100% 1RM. Small to moderate (d = 0.2-0.5) effect size differences were observed between the POW and OLY in joint angles and Fv, although none were statistically significant. However, significant joint angle results were observed between the experienced POW/OLY and the recreationally trained group. Our findings suggest that practitioners seeking to place emphasis on the stronger hip musculature should consider the LBBS. Also, when the goal is to lift the greatest load possible, the LBBS may be preferable. Conversely, the HBBS is more suited to replicate movements that exhibit a more upright torso position, such as the snatch and clean, or to place more emphasis on the associated musculature of the knee joint.