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The aim of this study was to assess the agreement of three different automated methods of identifying force-onset (40 N, 5 SDs, and 3 SDs) with manual identification, during the isometric mid-thigh pull (IMTP). Fourteen resistance-trained participants with >6 months experience training with the power clean volunteered to take part. After three familiarisation sessions, the participants performed five maximal IMTPs separated by 1 min of rest. Fixed bias was found between 40 N and manual identification for time at force-onset. No proportional bias was present between manual identification and any automated threshold. Fixed bias between manual identification and automated was present for force at onset and F150. Proportional but not fixed bias was found for F50 between manual identification and all automated thresholds. Small to moderate differences (Hedges g = −0.487- −0.692) were found for F90 between all automated thresholds and manual identification, while trivial to small differences (Hedges g = −0.122—−0.279) were found between methods for F200 and F250. Based on these results, strength and conditioning practitioners should not use a 40 N, 5 SDs, or 3 SDs threshold interchangeably with manual identification of force-onset when analysing IMTP force–time curve data.

This study investigated the stability of three repetition maximum (3RM) strength during the deadlift. Eleven participants performed four testing sessions comprising a one repetition maximum test and 3RM tests separated by 48 h. Preparedness was assessed before each testing session using countermovement jumps and by measuring barbell velocity during each set of deadlifts. Trivial statistically significant differences were determined for the 3RM between T1 and both T2 ( p = 0.012; ES [95% CI] = −0.1 [−0.58, 0.41]) and T3 ( p = 0.027; ES [95% CI] = −0.09 [−0.57, −0.43]). No significant differences were noted between T2 and T3 ( p = 0.595; ES [95% CI] = 0.01 [−0.49, 0.50]). No significant differences in jump height ( p = 0.071), time-to-take-off ( p = 0.862), eccentric displacement ( p = 0.209), or mean force during any countermovement jump sub-phase were found between each session ( p = 0.529–0.913). Small differences in barbell mean velocity were found between both T1–T2 (effect size statistics (ES) = −0.21–0.27) and T2–T3 (ES = 0.31–0.48), while trivial differences were found at others. Therefore, 3RM deadlift strength appears stable enough over a microcycle to continue using traditionally recommended heavy/light programming strategies.

The primary aim of this study was to investigate the stability of the six-repetition maximum (6RM) deadlift over the length of a five-day microcycle and whether the fatigue induced by maximal effort testing detrimentally impacted preparedness. Twelve participants performed four testing sessions, comprising a one-repetition maximum test and three 6RM tests separated by 48 hours. Countermovement jumps were performed before each testing session, and barbell velocity was measured during each warm-up set to assess changes in preparedness. The 6RM deadlift was not statistically different between any of the testing sessions ( p = .056; ηp2 = 0.251). Similarly, there were no significant differences in jump height or other CMJ variables between sessions ( p > .05). There were small to moderate differences in mean barbell velocity between the first and second 6RM test ( g = 0.24–0.88), while there were only small differences in mean velocity (MV) between the second and third 6RM test at some of the warm-up loads (40% 6RM: g = 0.20; 80% 6RM: g = −0.47). Taken collectively, these data indicate that 6RM deadlift strength is stable over five days and does not appear to induce sufficient fatigue to impact vertical jump performance or rating of perceived exertion despite some changes in barbell velocity.

Kotani, Y, Lake, J, Guppy, SN, Poon, W, Nosaka, K, Hori, N, and Haff, GG. The reliability of the squat jump force-velocity and load-velocity profiles. J Strength Cond Res XX(X): 000-000, 2021-The purpose of this study was to investigate the between-session reliability of the squat jump force-velocity (FV) and load-velocity (LV) profiles. Eighteen subjects (age = 28.1 ± 4.8 years; height = 1.7 ± 9.7; body mass = 74.7 ± 12.8) who could back squat >1.5 times body mass participated in this study. Each subject completed a familiarization session, followed by 2 experimental sessions each separated by 72 hours. Subjects performed a series of squat jumps on a force plate against external loads between 0 and 100% of their body mass in a quasi-randomized block order. Intraclass correlation coefficient (ICC) and coefficient of variation (CV) were used to examine the between-session reliability. Peak velocity (PV) and mean velocity (MV) at each load were highly reliable (ICC >0.80, CV%

Force plates are commonly used when assessing vertical jumping performance but are not always affordable or practical tools for all testing situations. Twenty-four participants volunteered to take part in a study investigating the agreement between bilateral force plates and a new commercially available contact mat that records jump height, flight-time (FT), and FT of individual limbs during both countermovement (CMJ) and squat (SJ) jumps. Each participant performed six jumps of each type while standing on a contact mat placed upon a pair of in-ground force plates. When compared to the force plate via ordinary least products regression, the contact mat agreed with force plate CMJ and SJ jump height, individual limb FT during CMJs, and left-leg FT during SJs. The bilateral contact mat provided valid assessment of individual limb FT during CMJs, but not SJs. Practitioners can therefore use a bilateral contact mat interchangeably with bilateral force plates to measure SJ and CMJ performance.

Guppy, SN, Kotani, Y, Brady, CJ, Connolly, S, Comfort, P, and Haff, GG. Title: The reliability and magnitude of time-dependent force-time characteristics during the isometric mid-thigh pull are impacted by both testing protocol and analysis choices. J Strength Cond Res 36(5): 1191-1199, 2022-This study aimed to investigate whether the use of short-duration (SHORT) isometric midthigh pull (IMTP) trials resulted in greater reliability and magnitude of time-dependent force-time characteristics than traditionally performed IMTP trials (TRAD). Fourteen subjects with6 months' training experience with the power clean volunteered to take part in the study. Subjects performed five ∼1-second IMTP trials (SHORT) and five 5-second IMTP trials (TRAD). SHORT resulted in substantially more reliable rate of force development (RFD) measures (intraclass correlation coefficient [ICC] = 0.97-0.99; coefficient of variation [CV] = 2.6-7.0%), particularly during time bands from force-onset to 150 ms, compared with TRAD when trials were selected for analysis based on peak force (ICC = 0.66-0.83; CV = 14.1-38.5%). Selecting TRAD trials based on RFD0-200 resulted in similar reliability compared with SHORT of those same epochs (ICC = 0.97-0.99; CV = 2.5-7.8%). Furthermore, SHORT resulted in significantly greater force at specific time points, RFD, and impulse compared with TRAD trials (p = 0.001-0.033; g = -0.16 to -0.66). Based on these results, strength and conditioning professionals should use specific testing protocols (i.e., TRAD and SHORT) depending on the component of an athlete's force-generating capacity that they wish to assess and remain aware of the effect analysis choices they have on the reliability of IMTP force-time characteristics.

Mixed martial arts (MMA) is a combat sport that employs techniques from different combat disciplines. There are a multitude of technical and physiological characteristics that contribute to competitive success. Developing a single scientific assessment that can predict competitive outcomes poses great difficulty due to the complexity of MMA. While previous research has investigated some important physiological characteristics, there is no accepted best-practice for a comprehensive testing battery. As such, this study aimed to design and utilize a battery of physiological assessments to cover aerobic and anaerobic function, strength measures including explosive and maximal strength, body composition and repeat effort ability in Australian MMA athletes. Six participants with competitive experience were recruited. Testing involved a familiarization, three experimental sessions and including assessments such as the isometric midthigh pull, Wingate test, graded exercise test, countermovement jump and body composition scan. Results showed the testing battery in this study was realistic and able to be completed by the participants without issue and that regional Australian MMA athletes were similar physiologically to elite standard compared with previous research taken from a range of sources. However, future research with the testing battery is required with larger and more diverse samples to better understand the full profiles of MMA athletes. The results of the study can help inform athletes, researchers and support staff alike when deciding upon which testing protocols to use for MMA athletes. Future research should aim to develop normative data using the battery proposed in the current study.

This study aimed to investigate the effect of different set configurations on barbell trajectories during a series of power snatch sets. Ten strength-power athletes (height: 1.78 ± 0.09 m, body mass: 88.7 ± 14.3 kg, age: 28.9 ± 4.8 years) with at least 6 months of training experience performing the power snatch participated in this study. Each participant completed three experimental protocols as part of a randomized repeated measures design. The three protocols tested were a traditional, cluster, and ascending cluster set protocol where training loads were increased across the repetitions contained within each set. All protocols required each participant to perform the power snatch with three sets of five repetitions at an average load of 75% of one-repetition maximum. Three-dimensional barbell trajectories were recorded using a motion capture system during each set protocol. Participants maintained barbell trajectories within each set of both traditional and cluster protocols. This result indicates that higher intensities (>75% of one-repetition maximum) than those used in this study should be used when using cluster sets that are designed to maximize the benefits of cluster sets for maintaining barbell trajectories during a series of power snatch sets performed for five repetitions. Additionally, participants displayed an increased barbell loop at the first repetition during the ascending cluster protocol. Therefore, coaches should only use this programming strategy for highly trained athletes who have already developed proper weightlifting technique to avoid a suboptimal barbell trajectory during the power snatch training session.

Guppy, SN, Brady, CJ, Kotani, Y, Stone, MH, Medic, N, and Haff, GG. Effect of altering body posture and barbell position on the within-session reliability and magnitude of force-time curve characteristics in the isometric midthigh pull. J Strength Cond Res 33(12): 3252-3262, 2019-A large degree of variation in the position used during isometric midthigh pull (IMTP) testing and conflicting results of the effects of these changes can be found in the literature. This study investigated the effect of altering body posture and barbell position on the reliability and magnitude of force-time characteristics generated during the IMTP. Seventeen strength-power athletes (n = 11 males, height: 177.5 ± 7.0 cm, body mass: 90.0 ± 14.1 kg, age: 30.6 ± 10.4 years; n = 6 females, height: 165.8 ± 11.4 cm; body mass: 66.4 ± 13.9 kg, age: 30.8 ± 8.7 years) with greater than 6 months of training experience in the clean (1 repetition maximum: 118.5 ± 20.6 kg, 77.5 ± 10.4 kg) volunteered to undertake the experimental protocol. Subjects performed the IMTP using 4 combinations of hip and knee angles, and 2 different barbell positions. The first barbell position corresponded to the second pull of the clean, while the second rested at the midpoint between the iliac crest and the patella. Peak force (PF), time-specific force (F50, F90, F150, F200, and F250), peak rate of force development (pRFD), and impulse (IMP) time bands were reliable in all 4 testing positions examined. Statistically greater PF, F50, F90, F150, F200, F250, pRFD, and IMP0-50, IMP0-90, IMP0-150, and IMP0-200 were generated in a testing position corresponding to the second pull of the clean when compared with a bent over torso angle, regardless of the barbell position used. Moderate to large effect sizes favoring a testing position corresponding to the second pull were also found. Overall, when performing the IMTP, an upright torso and a barbell position that matches the second pull of the clean should be used.

Copyright National Strength and Conditioning Association 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).

Combat sports encompass a range of sports, each involving physical combat between participants. Such sports are unique, with competitive success influenced by a diverse range of physical characteristics. Effectively identifying and evaluating each characteristic is essential for athletes and support staff alike. Previous research investigating the relationship between combat sports performance and measures of strength and power is robust. However, research investigating the relationship between combat sports performance and assessments of endurance is less conclusive. As a physical characteristic, endurance is complex and influenced by multiple factors including mechanical efficiency, maximal aerobic capacity, metabolic thresholds, and anaerobic capacities. To assess endurance of combat sports athletes, previous research has employed methods ranging from incremental exercise tests to circuits involving sports-specific techniques. These tests range in their ability to discern various physiological attributes or performance characteristics, with varying levels of accuracy and ecological validity. In fact, it is unclear how various physiological attributes influence combat sport endurance performance. Further, the sensitivity of sports specific skills in performance based tests is also unclear. When developing or utilizing tests to better understand an athletes’ combat sports-specific endurance characteristic, it is important to consider what information the test will and will not provide. Additionally, it is important to determine which combination of performance and physiological assessments will provide the most comprehensive picture. Strengthening the understanding of assessing combat sport-specific endurance as a physiological process and as a performance metric will improve the quality of future research and help support staff effectively monitor their athlete’s characteristics.

Seventeen strength and power athletes (n = 11 males, 6 females, height: 177.5 &plusmn, 7.0 cm, 165.8 &plusmn, 11.4 cm, body mass: 90.0 &plusmn, 14.1 kg, 66.4 &plusmn, 13.9 kg, age: 30.6 &plusmn, 10.4 years, 30.8 &plusmn, 8.7 years), who regularly performed weightlifting movements during their resistance training programs, were recruited to examine the effect of altering body posture and barbell position on the between-session reliability of force-time characteristics generated in the isometric mid-thigh pull (IMTP). After participants were familiarised with the testing protocol, they undertook two testing sessions which were separated by seven days. In each session, the participants performed three maximal IMTP trials in each of the four testing positions examined, with the order of testing randomized. In each position, no significant differences were found between sessions for all force-time characteristics (p = &gt, 0.05). Peak force (PF), time-specific force (F50, F90, F150, F200, F250) and IMP time-bands (0&ndash, 50, 0&ndash, 90, 0&ndash, 150, 0&ndash, 200, 0&ndash, 250 ms) were reliable across each of the four testing positions (ICC &ge, 0.7, CV &le, 15%). Time to peak force, peak RFD, RFD time-bands (0&ndash, 250 ms) and peak IMP were unreliable regardless of the testing position used (ICC = &lt, 0.7, CV = &gt, 15%). Overall, the use of body postures and barbell positions during the IMTP that do not correspond to the second pull of the clean have no adverse effect on the reliability of the force-time characteristics generated.