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Isometric training is used in the rehabilitation and physical preparation of athletes, special populations, and the general public. However, little consensus exists regarding training guidelines for a variety of desired outcomes. Understanding the adaptive response to specific loading parameters would be of benefit to practitioners. The objective of this systematic review, therefore, was to detail the medium‐ to long‐term adaptations of different types of isometric training on morphological, neurological, and performance variables. Exploration of the relevant subject matter was performed through MEDLINE, PubMed, SPORTDiscus, and CINAHL databases. English, full‐text, peer‐reviewed journal articles and unpublished doctoral dissertations investigating medium‐ to long‐term (≥3 weeks) adaptations to isometric training in humans were identified. These studies were evaluated further for methodological quality. Twenty‐six research outputs were reviewed. Isometric training at longer muscle lengths (0.86%‐1.69%/week, ES = 0.03‐0.09/week) produced greater muscular hypertrophy when compared to equal volumes of shorter muscle length training (0.08%‐0.83%/week, ES = −0.003 to 0.07/week). Ballistic intent resulted in greater neuromuscular activation (1.04%‐10.5%/week, ES = 0.02‐0.31/week vs 1.64%‐5.53%/week, ES = 0.03‐0.20/week) and rapid force production (1.2%‐13.4%/week, ES = 0.05‐0.61/week vs 1.01%‐8.13%/week, ES = 0.06‐0.22/week). Substantial improvements in muscular hypertrophy and maximal force production were reported regardless of training intensity. High‐intensity (≥70%) contractions are required for improving tendon structure and function. Additionally, long muscle length training results in greater transference to dynamic performance. Despite relatively few studies meeting the inclusion criteria, this review provides practitioners with insight into which isometric training variables (eg, joint angle, intensity, intent) to manipulate to achieve desired morphological and neuromuscular adaptations.

Weightlifting is a dynamic strength and power sport in which two, multijoint, whole-body lifts are performed in competition; the snatch and clean and jerk. During the performance of these lifts, weightlifters have achieved some of the highest absolute and relative peak power outputs reported in the literature. The training structure of competitive weightlifters is characterized by the frequent use of high-intensity resistance exercise movements. Varied coaching and training philosophies currently exist around the world and further research is required to substantiate the best type of training programme for male and female weightlifters of various age groups. As competitive weightlifting is contested over eight male and seven female body weight categories, the anthropometric characteristics of the athletes widely ranges. The body compositions of weightlifters are similar to that of athletes of comparable body mass in other strength and power sports. However, the shorter height and limb lengths of weightlifters provide mechanical advantages when lifting heavy loads by reducing the mechanical torque and the vertical distance that the barbell must be displaced. Furthermore, the shorter body dimensions coincide with a greater mean skeletal muscle cross-sectional area that is advantageous to weightlifting performance. Weightlifting training induces a high metabolic cost. Although dietary records demonstrate that weightlifters typically meet their required daily energy intake, weightlifters have been shown to over consume protein and fat at the expense of adequate carbohydrate. The resulting macronutrient imbalance may not yield optimal performance gains. Cross-sectional data suggest that weightlifting training induces type IIX to IIA fibre-type transformation. Furthermore, weightlifters exhibit hypertrophy of type II fibres that is advantageous to weightlifting performance and maximal force production. As such, the isometric peak force and contractile rate of force development of weightlifters is ~15-20% and ~13-16% greater, respectively, than in other strength and power athletes. In addition, weightlifting training has been shown to reduce the typical sex-related difference in the expression of neuromuscular strength and power. However, this apparent sex-related difference appears to be augmented with increasing adult age demonstrating that women undergo a greater age-related decline in muscle shortening velocity and peak power when compared with men. Weightlifting training and competition has been shown to induce significant structural and functional adaptations of the cardiovascular system. The collective evidence shows that these adaptations are physiological as opposed to pathological. Finally, the acute exercise-induced testosterone, cortisol and growth hormone responses of weightlifters have similarities to that of following conventional strength and hypertrophy protocols involving large muscle mass exercises. The routine assessment of the basal testosterone : cortisol ratio may be beneficial when attempting to ...

Purpose: To investigate differences between rating of perceived exertion (RPE) and percentage one-repetition maximum (1RM) load assignment in resistance-trained males (19–35 years) performing protocols with matched sets and repetitions differentiated by load-assignment.Methods: Participants performed squats then bench press 3x/weeks in a daily undulating format over 8-weeks. Participants were counterbalanced by pre-test 1RM then assigned to percentage 1RM (1RMG, n = 11); load-assignment via percentage 1RMs, or RPE groups (RPEG, n = 10); participant-selected loads to reach target RPE ranges. Ultrasonography determined pre and post-test pectoralis (PMT), and vastus lateralis muscle thickness at 50 (VLMT50) and 70% (VLMT70) femur-length.Results: Bench press (1RMG +9.64 ± 5.36; RPEG + 10.70 ± 3.30 kg), squat (1RMG + 13.91 ± 5.89; RPEG + 17.05 ± 5.44 kg) and their combined-total 1RMs (1RMG + 23.55 ± 10.38; RPEG + 27.75 ± 7.94 kg) increased (p < 0.05) in both groups as did PMT (1RMG + 1.59 ± 1.33; RPEG +1.90 ± 1.91 mm), VLMT50 (1RMG +2.13 ± 1.95; RPEG + 1.85 ± 1.97 mm) and VLMT70 (1RMG + 2.40 ± 2.22; RPEG + 2.31 ± 2.27 mm). Between-group differences were non-significant (p > 0.05). Magnitude-based inferences revealed 79, 57, and 72% chances of mean small effect size (ES) advantages for squat; ES 90% confidence limits (CL) = 0.50 ± 0.63, bench press; ES 90% CL = 0.28 ± 0.73, and combined-total; ES 90% CL = 0.48 ± 0.68 respectively, in RPEG. There were 4, 14, and 6% chances 1RMG had a strength advantage of the same magnitude, and 18, 29, and 22% chances, respectively of trivial differences between groups.Conclusions: Both loading-types are effective. However, RPE-based loading may provide a small 1RM strength advantage in a majority of individuals.

Helms, ER, Storey, A, Cross, MR, Browm, SR, Lenetsky, S, Ramsay, H, Dillen, C, and Zourdos, MC. RPE and velocity relationships for the back squat, bench press, and deadlift in powerlifters. J Strength Cond Res 31(2): 292-297, 2017-The purpose of this study was to compare average concentric velocity (ACV) and rating of perceived exertion (RPE) based on repetitions in reserve on the squat, bench press, and deadlift. Fifteen powerlifters (3 women and 12 men, mean age 28.4 ± 8.5 years) worked up to a one repetition maximum (1RM) on each lift. Rating of perceived exertion was recorded on all sets, and the ACV was recorded for all sets performed at 80% of estimated 1RM and higher, up to 1RM. Rating of perceived exertion at 1RM on squat, bench press, and deadlift was 9.6 ± 0.5, 9.7 ± 0.4, and 9.6 ± 0.5, respectively and was not significantly different (p > 0.05). The ACV at 1RM on squat, bench press and deadlift was 0.23 ± 0.05, 0.10 ± 0.04, and 0.14 ± 0.05 m·second, respectively. Squat was faster than both bench press and deadlift (p > 0.001), and deadlift was faster than bench press (p = 0.05). Very strong relationships (r = 0.88-0.91) between percentage 1RM and RPE were observed on each lift. The ACV showed strong (r = -0.79 to -0.87) and very strong (r = -0.90 to 92) inverse relationships with RPE and percentage 1RM on each lift, respectively. We conclude that RPE may be a useful tool for prescribing intensity for squat, bench press, and deadlift in powerlifters, in addition to traditional methods such as percentage of 1RM. Despite high correlations between percentage 1RM and ACV, a "velocity load profile" should be developed to prescribe intensity on an individual basis with appropriate accuracy.