15 research outputs found
Autoregulation in resistance training : addressing the inconsistencies
Autoregulation is a process that is used to manipulate training based primarily on the measurement of an individual's performance or their perceived capability to perform. Despite being established as a training framework since the 1940s, there has been limited systematic research investigating its broad utility. Instead, researchers have focused on disparate practices that can be considered specific examples of the broader autoregulation training framework. A primary limitation of previous research includes inconsistent use of key terminology (e.g., adaptation, readiness, fatigue, and response) and associated ambiguity of how to implement different autoregulation strategies. Crucially, this ambiguity in terminology and failure to provide a holistic overview of autoregulation limits the synthesis of existing research findings and their dissemination to practitioners working in both performance and health contexts. Therefore, the purpose of the current review was threefold: first, we provide a broad overview of various autoregulation strategies and their development in both research and practice whilst highlighting the inconsistencies in definitions and terminology that currently exist. Second, we present an overarching conceptual framework that can be used to generate operational definitions and contextualise autoregulation within broader training theory. Finally, we show how previous definitions of autoregulation fit within the proposed framework and provide specific examples of how common practices may be viewed, highlighting their individual subtleties
Effects of conditioning hops on drop jump and sprint performance: a randomized crossover pilot study in elite athletes
BACKGROUND: It has previously been shown that conditioning activities consisting of repetitive hops have the potential to induce better drop jump (DJ) performance in recreationally active individuals. In the present pilot study, we investigated whether repetitive conditioning hops can also increase reactive jump and sprint performance in sprint-trained elite athletes competing at an international level. METHODS: Jump and sprint performances of 5 athletes were randomly assessed under 2 conditions. The control condition (CON) comprised 8 DJs and 4 trials of 30-m sprints. The intervention condition (HOP) consisted of 10 maximal repetitive two-legged hops that were conducted 10Â s prior to each single DJ and sprint trial. DJ performance was analyzed using a one-dimensional ground reaction force plate. Step length (SL), contact time (CT), and sprint time (ST) during the 30-m sprints were recorded using an opto-electronic measurement system. RESULTS: Following the conditioning activity, DJ height and external DJ peak power were both significantly increased by 11Â % compared to the control condition. All other variables did not show any significant differences between HOP and CON. CONCLUSIONS: In the present pilot study, we were able to demonstrate large improvements in DJ performance even in sprint-trained elite athletes following a conditioning activity consisting of maximal two-legged repetitive hops. This strengthens the hypothesis that plyometric conditioning exercises can induce performance enhancements in elite athletes that are even greater than those observed in recreationally active athletes.. In addition, it appears that the transfer of these effects to other stretch-shortening cycle activities is limited, as we did not observe any changes in sprint performance following the plyometric conditioning activity
TESTING MODALITY IS VITAL TO DETECT PERFORMANCE CHANGES IN OVERREACHING RESISTANCE EXERCISE
Justin Nicoll1, Andrew C. Fry1, Loren Z. F. Chiu2, Brian K. Schilling3 & Lawrence W. Weiss3, FACSM
1University of Kansas, Lawrence, Kansas; 2University of Alberta, Edmonton, Alberta, Canada; 3University of Memphis, Memphis, Tennessee
Non-functional overreaching (NFOR) is detrimental to resistance exercise (RE) performance. Research concerning sensitive and sport specific methods that identify NFOR is sparse, and inconsistencies of results may be due to differences in testing modalities. PURPOSE: The purpose of this study was to compare muscle performance using different testing modalities (dynamic vs. isometric) after high power RE overreaching (OR). METHODS: As part of a larger dietary supplementation study, seventeen men (n=17; X±SD; age: 22.8±3.3yrs) were randomly assigned to a supplement (SUPP; n=8; body mass: 88.28±16.7kg; bodyfat: 11.7±6.4%), placebo (PL: n=3; bodymass: 86.66±25.7kg; bodyfat: 12.9±10.8%), or control (CON; n=6; body mass: 76.63±8.4kg, bodyfat: 11.3±6.8%) group. All groups participated in two weeks of normal training. After normal training, SUPP and PL performed OR for one week, while CON continued normal training. External mean power (MP), force (MF), and velocity (MV) were determined for the barbell squat exercise at 70% 1-RM load. Maximum isometric force, and rate of force development were determined using the isometric knee extension exercise on leg-extension machine interfaced with a force transducer. Performance data was collected at baseline (BL), after two weeks of normal training (Pre-OR), after OR phase (Post-OR), and after one week of recovery (POST). A 3x4 (group x time) repeated-measures ANOVA with Fisher LSD post-hoc was used to determine differences between groups and time. Significance was set at pRESULTS: There were no significant differences in knee extension variables (p\u3e0.05). MF was higher in PL at Post-OR compared to BL and Pre-OR (2037 ± 626N vs. 1626±40N & 1581±92N; p-1 vs 78.7±11.3cm.s-1 & 75.3±6.7cm.s-1; p-1 vs 70.4±2.9cm.s-1 & 69.0±6.4cm.s-1; p0.05). CONCLUSION: Only dynamic RE (barbell squat) was sensitive to detect decreased performance compared to isometric RE (knee extension) in overreached subjects. Similarly, it appears power and velocity are more adversely affected by OR than measures of maximal force.
Funding provided by Nutricia
HIGH POWER RESISTANCE EXERCISE OVERREACHING DOES NOT EFFECT TESTOSTERONE AND CORTISOL CONCENTRATIONS
Adam J. Sterczala1, Andrew C. Fry1, Loren Z.F. Chiu2, Brian K. Schilling3 & Lawrence W. Weiss3 FACSM
1University of Kansas, Lawrence, Kansas, 2University of Alberta, Calgary, Alberta, Canada, 3University of Memphis, Memphis, Tennessee
Overreaching is a lesser form of overtraining, which results in similar performance decrements, but a shorter recovery time. Resistance exercise overreaching protocols have routinely demonstrated performance decrements, however the effects on hormonal measures have differed, depending on the protocol used. PURPOSE: To determine the effects of a high power, high volume, moderate intensity resistance exercise protocol on performance and hormonal measures. METHODS: Seventeen resistance-trained men (n=17; X±SD; age=22.8±3.3 yrs), were assigned to three groups, control (CON, n=6), overreaching-supplement (SUP, n=8) and overreaching-placebo (PL: n=3) as part of a larger study evaluating the effects of a nutritional supplement on overreaching. All subjects completed four resistance exercise bouts consisting three sets of five repetitions of speed squats using 70% 1RM. In the third week, the CON trained twice more with the same protocol, while SUP and PL trained twice per day for 7.5 days, performing ten sets of five repetitions using 70% 1RM. Subjects were instructed to perform all repetitions with maximal velocity. Blood samples were taken at baseline (T1), before the third week (T2), after the third week (T4) and following a one-week recovery period (T4). Commercially available ELISAs were used to measure serum testosterone and cortisol concentrations. A barbell-attached dynamometer was used to determine back squat mean power and barbell velocity at 70% 1RM. RESULTS: CON demonstrated no changes in mean back squat power or velocity at any time point. In contrast, significant differences in barbell velocity and power were observed in SUP and PL at T3. Performance measures returned to T1 values by T4. Despite these performance decrements, no significant changes were observed in testosterone, cortisol or the testosterone/cortisol ratio. Aside from attenuated performance, changes in nocturnal catecholamine release, β2 adrenergic receptor content, and psychological variables suggest that subjects in the SUP and PL groups experienced overreaching. CONCLUSION: The overreached subjects demonstrated significant performance decrements in the absence of hormonal changes. Consequently, the results of this investigation suggest that testosterone, cortisol and the testosterone/cortisol ratio may not be valid measures for diagnosis of resistance exercise overreaching
HIGH POWER RESISTANCE EXERCISE OVER-REACHING CAN BE MONITORED WITH A TRAINING QUESTIONNAIRE
Andrew C. Fry1, Mary D. Fry1, Adam J. Sterczala1, Loren Z.F. Chiu2, Brian K. Schilling3 & Lawrence W. Weiss3.
1University of Kansas, Lawrence, Kansas, 2University of Alberta, Calgary, Alberta, Canada, 3University of Memphis, Memphis, Tennessee
Overtraining resulting in long-term performance decrements due to high intensity resistance exercise is associated with changes in daily training questionnaires (Fry et al. 1994, 2006). A lesser form of overtraining that can be part of a planned training program is called over-reaching (OR) and results in performance decrements lasting just a few days to a few weeks. PURPOSE: To determine if a daily training questionnaire can determine the onset of over-reaching due to high power resistance exercise. METHODS: As part of a larger study on dietary supplementation, weight trained males (n=17; X±SD; age=22.8±3.3 yrs) were divided into OR+supplement (SUP; n=8), OR+placebo (PL; n=3), or control (CON; n=6) groups. Both OR groups performed 15 training sessions over 7.5 days, performing 10 x 5 speed squats at 70% BW+1 repetition maximum (RM) each session. Each training and testing session included a questionnaire (Fry et al. 2000) to determine perceptions of soreness, joint discomfort, and motivation to exercise. An abridged version of the Profile of Mood States (POMS) survey instrument was also administered (Myers & Whelan 1998), as well as a questionnaire to determine sleep patterns and other training related variables. RESULTS: Vol.-load (reps x wgt) for the OR groups was \u3e28-fold greater than for CON during the OR phase (both OR groups \u3e 146.103 kg; Con=5.1.103 kg). Overreaching occurred for both SUP & PL groups as indicated by lower bar velocity at 70% 1 RM at post OR, but was recovered after 1 week. Both OR groups decreased perceptions of recovery \u3e45% during the 15 training sessions (p22% less desire to train during the first 8 training sessions compared to the S group (p.05). No measure from the abridged POMS sig. changed (p\u3e.05). CONCLUSIONS: Use of a previously validated overtraining questionnaire appears to be valid for monitoring resistance exercise overreaching as well.
Supported by a grant from Nutricia
On self-propagating methodological flaws in performance normalization for strength and power sports
Performance in strength and power sports is greatly affected by a variety of anthropometric factors. The goal of performance normalization is to factor out the effects of confounding factors and compute a canonical (normalized) performance measure from the observed absolute performance. Performance normalization is applied in the ranking of elite athletes, as well as in the early stages of youth talent selection. Consequently, it is crucial that the process is principled and fair. The corpus of previous work on this topic, which is significant, is uniform in the methodology adopted. Performance normalization is universally reduced to a regression task: the collected performance data are used to fit a regression function that is then used to scale future performances. The present article demonstrates that this approach is fundamentally flawed. It inherently creates a bias that unfairly penalizes athletes with certain allometric characteristics, and, by virtue of its adoption in the ranking and selection of elite athletes, propagates and strengthens this bias over time. The main flaws are shown to originate in the criteria for selecting the data used for regression, as well as in the manner in which the regression model is applied in normalization. This analysis brings into light the aforesaid methodological flaws and motivates further work on the development of principled methods, the foundations of which are also laid out in this work