The isometric midthigh pull (imtp) is commonly used to assess an athlete’s force generation ability. this test is highly reliable and is simple and relatively quick to perform. the data that can be determined from the force–time curves generated by the test have been shown to be closely related to performance capacities in a variety of dynamic athletic tasks. however, within the scientific literature, there are inconsistencies in the data collection procedures and methods used for data analysis that may impact the resultant output and the ability to compare and generalize results. therefore, the primary aim of this review is to identify the differences in imtp testing procedures and data analysis techniques, whereas identifying the potential impact this may have on the data collected. the secondary aim is to provide recommendations for the standardization of testing procedures to ensure that future imtp data are of maximal benefit to practitioners and researchers. for a video abstract of this article, see supplemental digital content 1 (see video, http:// links.lww.com/scj/a249).

No description available.

Resistance training can alter a number of health-related and performance variables. These alterations include beneficial effects on body composition, blood pressure, and blood lipids and enhanced maximum strength, rate of force development, and power. These enhancements may translate into a better quality of life. As a result, resistance training can be used as a valuable tool in ameliorating the effects of a sedentary lifestyle, including those associated with metabolic syndrome. Nineteen subjects (10 metabolic syndrome, 9 previously sedentary nonmetabolic syndrome) underwent 8 weeks of supervised resistance training. After training, strength and V̇O2 peak increased by approximately 10% in the metabolic and nonmetabolic syndrome groups and the male and female groups. Percent body fat decreased in subjects with the metabolic syndrome and in females. Additionally, lean body mass increased in all groups (p<0.05). Eight weeks of resistance training improves several cardiovascular risk factors of metabolic syndrome.

The purpose of this study was to identify the anthropometric, strength, and power characteristics that best predict throwing performance. Seventeen male D-I throwers (age = 19.1 ± 1.2 y; body mass = 115.1 ± 15.3 kg; height = 1.85 ± 0.06 m) were assessed for maximum strength and power. A five variable linear regression (r = 0.94, r2 = 0.88, F(5,11) = 15.89, p < 0.001, SEE = 0.68) explained 88% of the variation in shot put (SP) performance. A five variable linear regression (r = 0.91, r2 = 0.83, F(5,11) = 10.509, p = 0.001, SEE = 1.18) explained 83% of the variation in weight throw (WT) performance. Both SP and WT correlated strongly with measures of explosive strength and power (r = 0.48-0.78). Best predictors of performance were static vertical jumps and 7.26 kilogram overhead shot throw; better throwers possess greater maximum strength and power.

Purpose: to examine the relationship between isometric force characteristics (IF) and vertical jump height under various loading conditions. Sixty-three collegiate athletes participated in this investigation. Athletes performed static jump (SJ) and countermovement jumps (CMJ) with 0 and 20kg, and isometric mid-thigh pulls on a force plate. Force-time curve analysis was conducted for each isometric pull and jump to determine force related characteristics. Jump height (JH) was derived from flight time. Isometric forces were normalized using allometric scaling: absolute force/ (body mass(kg)0.67)= IPFa. Results: There was a strong positive correlation between isometric peak force and isometric rate of force development (IRFD). Stronger athletes had smaller decrements in jump height with additional loading. Conclusion: The ability to produce higher peak and instantaneous forces and IRFD is related to JH and smaller differences between weighted and unweighted jumps. A weighted jump may be a practical method of assessing relative strength levels.

The purpose of this study was to observe physiological metrics relative to training-induced adaptations in conjunction with laboratory- and competition-based performances in a super-heavyweight weightlifter recovering from a meniscus injury. A retrospective analysis was conducted on a collegiate level male weightlifter (23.2 yrs; 131.9 kg; 187.3 cm) over the course of 21-weeks post-meniscus surgery. Body mass, body fat percentage, hydration status, vastus lateralis muscle cross-sectional area, jump performance, and isometric midthigh pull were regularly assessed as part of an ongoing athlete monitoring program. Pre-injury baseline (T0) measurements were collected relative to a major national competition (COMP1). Post-injury measurements took place at the end of sequential training blocks: strength-endurance training block 1 (T1), basic strength block 2 (T2), and transmutation block 3 (T3). The final measurement session (T4) was conducted three-days post-local competition (COMP2). Only statistically significant increases were observed from T0-T4 for muscle CSA (p=0.0367), isometric peak force (pp=0.0367), and rate of force development at 250ms (p=.0367). While non-significant changes were observed for jumping performance, jump height and net impulse did, however, return to baseline. Competition based performances also showed marked improvements from pre-to-post injury via an increase in weightlifting total (3.2%∆, +9kg) and Sinclair score (1.8%∆, +5.3au). Thus, based on these findings, implementing an evidence-based training program along with a sound athlete monitoring protocol can aid with reducing an athlete’s return-to-train timeline while improving physiological, laboratory- and competition-based performance outcomes.

The purpose of this study was to investigate the chronic effects of accentuated eccentric loading (AEL) paired with cluster sets (CS) on dynamic and maximal strength, the endocrine system, and body composition. Seventeen recreationally active subjects (male = 11, females = 6, age = 23.05 ± 4.07, height = 172.09 ± 9.98, body mass = 81.29 ± 22.18, back squat to body mass ratio = 1.55 ± 0.33, bench press to body mass ratio = 1.06 ± 0.28) participated in one familiarization week, 2 weeks of testing, and 4 weeks of training. A strength-endurance block (4 wks) was used for training in which the target load consisted of 3 sets of 10 repetitions. The AEL group performed 3 sets of 10 repetitions for the squat and bench press using AEL every other repetition (5 AEL repetitions per set). Because of this protocol, CS were also performed as one AEL repetition plus one traditional repetition followed by 15 s rest. Weight releasers were attached during the rest between clusters. Resistance training was performed three days a week, sprint and agility work were performed two days a week. Maximum dynamic strength (1 RM squat, 1RM bench press), isometric maximum strength (Isometric midthigh pull) and rate of force development (RFD) were tested before and after the training protocol. Additionally, Testosterone (T), Cortisol (C), and Creatinine (CREA), fat mass (FM) and fat free mass (FFM) were assessed pre and post-test in 16 of the subjects as blood was unable to be collected from one of the subjects post test. Although maximum strength increased over time (n= 17), no statistically significant differences in strength occurred between the AEL and TRAD protocols after 4 weeks of training. No statistically significant differences in resting blood variables or body composition occurred between the AEL and TRAD protocols after 4 weeks of training.

Neural activation is thought to be essential for the expression of maximal muscle performance, but the exact contribution of neural mechanisms such as the level of agonist, antagonist and stabiliser muscle activation to muscle strength is not fully understood. Explosive neuromuscular performance, including the ability to initiate (the electromechanical delay, EMD) and develop force rapidly (termed, rate of force development, RFD) are considered essential for the performance of explosive sporting tasks and joint stabilisation and thus injury avoidance. The thesis aimed to improve our understanding of the contribution of neural factors to muscle performance, with a specific focus on explosive neuromuscular performance. The work in this thesis utilised a range of approaches to achieve this aim. Initially, the association between muscle activation and rate of force development and EMD was established. Comparison of unilateral and bilateral actions was then undertaken. Finally interventions with the aim to both negatively affect and improve muscle strength, which included fatigue and resistance training (RT), respectively was undertaken and the neural contributions to changes in performance established. Agonist activation during the early phase of voluntary force production was shown to be an important determinant of voluntary EMD, explaining 41% of its inter-individual variability. Agonist activation was an important determinant of early, but not late phase RFD. Use of bilateral actions resulted in a reduction in explosive strength, which was thought to be due to differences in postural stability between unilateral and bilateral strength tasks. The level of stabiliser activation was strongly related to the level of agonist activation during the early phase of explosive force development and had a high association with explosive force production. Task-specific adaptations following isoinertial RT, specifically, the greater increase in isoinertial lifting strength than maximal isometric strength were due to training-specific changes in the level of agonist activation. High-intensity fatigue achieved a more substantial decline in explosive than maximal isometric strength, and this was postulated to be due to neural mechanisms, specifically decreased agonist activation. This work provides an in depth analysis of the neural contributions to maximal muscle performance.

Apesar das perdas provocadas pela sarcopenia, o sistema neuromuscular do idoso ainda mantém parte da sua plasticidade. No entanto, as adaptações promovidas pelos treinamentos de força (TF) e de potência (TP) não foram totalmente elucidadas, assim como se existem diferenças entre essas adaptações nessa população. Para responder tais questões, 43 idosos (63,8 ± 4,0 anos; 67,2 ±13,4kg e 160,2 ±8,4cm), inexperientes em treinamento com pesos e independentes participaram desse estudo. Os voluntários foram distribuídos em três grupos: GF (n= 14; 70 a 90% de 1RM), GP (n= 16; 30 a 50% de 1RM) e GC (n= 13, não treinou). Durante 16 semanas o GF e o GP realizaram duas sessões de treino semanalmente. Os resultados significantes foram: aumento de 42,7% em GF e 33,8% em GP no teste de 1RM (leg press) e 31% em GF e 25,4% em GP (chest press); aumento de 6% em GF e 3,6% em GP na ASTq; aumento de 22,4% em GF e 17,1% em GP na CVIM e uma diminuição de 28% em GF e 32% em GP no REM. Não houve diferenças significativas entre GF e GP nas variáveis analisadas. Nenhum dos grupos apresentou aumento no sinal eletromiográfico nem na TDF. Não houve alteração significativa na funcionalidade. Portanto, ainda que com características distintas, o TF e o TP são similares em relação às adaptações analisadas, equiparando-se como estratégias de treinamento eficazes no combate à sarcopenia e seus efeitos / In spite of sarcopenia-induced losses, elderly peoples neuromuscular system keeps its plasticity. However, strength and power training-induced adaptations have not been completely elucidated. It also unknown if these adaptations are related to elderly functionality. Fourty three healthy and independent old men and women (63.8 ± 4.0 yrs; 67.2 ±13.4kg e 160.2 ±8.4cm) with no resistance training experience volunteered for this study. Participants were randomly distributed into three groups: GF (n= 14; 70 - 90%-1RM), GP (n= 16; 30 - 50%-1RM) e GC (n= 13, no training). GF and GP trained twice a week for 16 weeks. Leg-press (42.7% in GF and 33.8% in GP) and chest-press 1-RM (31% in GF and 25.4% in GP), quadriceps cross sectional area (6% in GF and 3.6% in GP), maximal voluntary isometric contraction (22.4% in GF and 17.1% in GP) were significantly increased in both groups. Electromechanical delay decreased 28% in GF and 32% in GP. There were no significant differences between groups. EMG and rate of force development did not change throughout the training period. Only main effect of time was observed for the functional tests. These results suggest that even with different characteristics, both strength and power training induce similar neuromuscular adaptations. Thus, both training regimens are equally effective in preventing and treating sarcopenia

Abstract available in the Annual Coaches and Sport Science College.