maximal isometric force (i.e. MVC) force tasks. Participants attended the laboratory midmorning on 2 separate occasions to assess MVC force utilizing a uniaxial load cell attached either directly to the athlete through a harness (forward flexion, FF) or to a kayak ergometer for the remaining tasks
Darren Steeves, Leo J. Thornley, Joshua A. Goreham, Matthew J. Jordan, Scott C. Landry and Jonathon R. Fowles
Christos K. Argus, James R. Broatch, Aaron C. Petersen, Remco Polman, David J. Bishop and Shona Halson
An athlete’s ability to recover quickly is important when there is limited time between training and competition. As such, recovery strategies are commonly used to expedite the recovery process.
To determine the effectiveness of both cold-water immersion (CWI) and contrast water therapy (CWT) compared with control on short-term recovery (<4 h) after a single full-body resistance-training session.
Thirteen men (age 26 ± 5 y, weight 79 ± 7 kg, height 177 ± 5 cm) were assessed for perceptual (fatigue and soreness) and performance measures (maximal voluntary isometric contraction [MVC] of the knee extensors, weighted and unweighted countermovement jumps) before and immediately after the training session. Subjects then completed 1 of three 14-min recovery strategies (CWI, CWT, or passive sitting [CON]), with the perceptual and performance measures reassessed immediately, 2 h, and 4 h postrecovery.
Peak torque during MVC and jump performance were significantly decreased (P < .05) after the resistance-training session and remained depressed for at least 4 h postrecovery in all conditions. Neither CWI nor CWT had any effect on perceptual or performance measures over the 4-h recovery period.
CWI and CWT did not improve short-term (<4-h) recovery after a conventional resistance-training session.
Andrés Pérez, Domingo J. Ramos-Campo, Cristian Marín-Pagan, Francisco J. Martínez-Noguera, Linda H. Chung and Pedro E. Alcaraz
the dominant leg. The participants were familiarized with how to perform a maximal voluntary contraction (MVC) using the Biodex dynamometer (Biodex Medical Systems, New York, NY). Participants were seated upright with the knee angle set at 107°. A specific warm-up consisted in 3 submaximal
Asma Aloui, Anis Chaouachi, Hamdi Chtourou, Del P. Wong, Monoem Haddad, Karim Chamari and Nizar Souissi
This study examined the effects of Ramadan on cycling repeated-sprint ability (RSA) and corresponding diurnal variations.
Twelve active men performed an RSA test (5 × 6-s maximal sprints interspersed with 24 s passive recovery) during morning and afternoon sessions 1 wk before Ramadan (BR), during the second (R2) and the fourth (R4) weeks of Ramadan, and 2 wk after Ramadan (AR). Maximal voluntary contraction was assessed before (MVCpre), immediately after (MVCpost), and 5 min after the RSA test (MVCpost5). Moreover, hematocrit, hemoglobin, and plasma sodium and potassium (K+) concentrations were measured at rest and after the RSA test and MVCpost.
Overall, peak power (Ppeak) during the RSA test decreased throughout the 5 sprints. Ppeak measured in the first sprint and MVCpre were lower during Ramadan than BR in the afternoon (P < .05) and higher in the afternoon than the morning BR and AR (P < .05). However, this diurnal rhythmicity was not found for the last 4 sprints’ Ppeak, MVCpost, and MVCpost5 in all testing periods. Furthermore, the last 4 sprints’ Ppeak, MVCpost, MVCpost5, and morning MVCpre were not affected by Ramadan. [K+] measured at rest and after the RSA test and MVCpost were higher during Ramadan than BR in the afternoon (P < .05) and higher in the afternoon than the morning during Ramadan (P < .05).
Fatigability is higher in the afternoon during Ramadan, and, therefore, training and competition should be scheduled at the time of day when physical performance is less affected.
David Phillips and Andrew Karduna
and height of the load cell was adjusted for each testing angle so that the forearm was flush with the surface of the load cell. A single 5-second maximal voluntary contraction (MVC) for each humeral elevation angle was recorded prior to the first session of testing. Following the MVCs, IRCs were
Marco J. Konings, Jordan Parkinson, Inge Zijdewind and Florentina J. Hettinga
perform a self-paced 4-km cycling TT as fast as possible. Before and after the TTs, maximal voluntary contraction (MVC), doublet twitches at rest, and voluntary activation of the quadriceps muscle (VA) were determined. The first 4-km TT was always a familiarization TT (FAM). In the final 2 visits
Daria Neyroud, Jimmy Samararatne, Bengt Kayser and Nicolas Place
intensity for femoral nerve stimulation was determined. 20 After a warm-up of 8 to 10 submaximal contractions (20–80% of estimated maximal voluntary contraction [MVC]), KE neuromuscular function was evaluated. Participants executed 2 to 3 KE MVCs for ∼4 seconds (no more than 5% variation was tolerated
Graeme G. Sorbie, Fergal M. Grace, Yaodong Gu, Julien S. Baker and Ukadike C. Ugbolue
maximum voluntary contraction (MVC) before and after the golf practice session. The current study also aimed to investigate the changes, if any, in club head speed, ball speed, and absolute carry distance when performing the golf practice session. It was hypothesized that the golf practice session would
Jonathan C. Reid, Rebecca M. Greene, Nehara Herat, Daniel D. Hodgson, Israel Halperin and David G. Behm
Contrary to adult force reserve strategies, it is not known whether adolescent females with less experience performing maximal voluntary contractions (MVC) have specific responses to a known or unknown fatigue endpoint.
Using a counterbalanced random crossover design, fourteen inexperienced female adolescents completed three elbow flexor (EF) fatiguing protocols. Participants were randomly assigned to a control (informed they would perform 12 MVCs), unknown (not informed of the number of MVCs to be completed, but stopped after 12) or deception condition (instructed to complete 6 MVCs, however, after the sixth repetition performed another 6 MVCs). Before and during the interventions, EF impulse, force, and biceps brachii (BB) and triceps brachii (TB) electromyography (EMG) activity were recorded. Results: Participants exhibited decreases in impulse (10.9%; p < .05), force (7.5%; p = .001), BB (16.2%; p < .05) and TB (12.9%; p < .05) EMG activity between the pretest and the first repetition of all protocols. Knowledge of endpoint, or lack of it, did not change measures with the repeated MVCs. When informed about the final repetition, force remained depressed suggesting no physiological reserve.
Adolescent females exhibited an anticipatory response to the task of performing repeated MVCs. A lack of change with knowledge of endpoint indicates that those lacking in MVC experience do not employ the same pacing strategies as in previous studies of participants with MVC experience.
Christopher A. Knight, Adam R. Marmon and Dhiraj H. Poojari
Subjects learned to produce brief isometric force pulses that were 10% of their maximal voluntary contraction (MVC) force. Subjects became proficient at performing sets of 10 pulses within boundaries of 8–12% MVC, with visual feedback and without (kinesthetic sense). In both the control (Con, n = 10) and experimental (Exp, n = 20) groups, subjects performed two sets of 10 kinesthetically guided pulses. Subjects then either performed a 10-s MVC (Exp) or remained at rest (Con) between sets. Following the MVC, Exp subjects had force errors of +30%, whereas performance was maintained in Con. There was evidence for both muscular and neural contributions to these errors. Postactivation potentiation resulted in a 40% gain in muscle contractility (p = .003), and there was a 26% increase in the neural stimulation of muscle (p = .014). Multiple regression indicated that the change in neural input had a stronger relationship with force errors than the increased contractility.