used to determine appropriate relative exercise protocol intensities for each participant. The main testing session required the participants to complete the Loughborough Soccer Passing Test (LSPT) prior to, during, and following 90 minutes of the LIST. Methodology For the preliminary testing measures
Mikayla J. Lyons, Jennifer Conlon, Amy Perejmibida, Paola Chivers, and Christopher Joyce
Julia Zakrzewski and Keith Tolfrey
Consensus on the exercise protocol used to measure Fatmax (exercise intensity corresponding to maximum fat oxidation (MFO)) in children has not been reached. The present study compared Fatmax estimated using the 3 min incremental cycling protocol (3-INC) and a protocol consisting of several 10 min constant work rate exercise bouts (10-CWR) in 26 prepubertal children. Group Fatmax values were the same for 3-INC and 10-CWR (55% VO2peak) and 95% limits of agreement (LoA) were ± 7% VO2peak. Group MFO values were similar between protocols, although 95% LoA were -94 to 113 mg·min−1. While 3-INC provides a valid estimation of Fatmax compared with 10-CWR, caution should be exercised when estimating MFO in prepubertal children.
Esther Suter, Walter Herzog, and Robert Bray
This study assessed muscle inhibition in patients with chronic anterior cruciate ligament (ACL) deficiency or ACL reconstruction. A series of protocols were tested for their effectiveness in increasing activity of the individual knee extensor muscles and decreasing muscle inhibition of the whole quadriceps group. Quadriceps muscle inhibition was measured by superimposing an electrical twitch onto the quadriceps muscle during a maximal voluntary knee extension. The level of activation of the individual knee extensor and knee flexor muscles was assessed via electromyography (EMG). Patients with ACL pathologies showed strength deficits and muscle inhibition in the knee extensors of the involved leg and the contralateral leg. Muscle inhibition was statistically significantly greater in ACL-deficient patients compared to ACL-reconstructed patients. When a knee extension was performed in combination with a hip extension, there was a significant increase, p < 0.05, in activation of the vastus medialis and vastus lateralis muscles compared to isolated knee extension. The use of an anti-shear device, designed to help stabilize the ACL-deficient knee, resulted in increased inhibition in the quadriceps muscle. Furthermore, a relatively more complete activation of the vasti compared to the rectus femoris was achieved during a fatiguing isometric contraction. Based on the results of this study, it is concluded that performing knee extension in combination with hip extension, or performing fatiguing knee extensor contractions, may be more effective in fully activating the vasti muscles than an isolated knee extensor contraction. Training interventions are needed to establish whether these exercise protocols are more effective than traditional rehabilitation approaches in decreasing muscle inhibition and achieving better functional recovery, including equal muscle strength in the injured and the contralateral leg.
Daniela A. Rubin, Diobel M. Castner, Hoang Pham, Jason Ng, Eric Adams, and Daniel A. Judelson
During childhood, varying exercise modalities are recommended to stimulate normal growth, development, and health. This project investigated hormonal and metabolic responses triggered by a resistance exercise protocol in lean children (age: 9.3 ± 1.4 y, body fat: 18.3 ± 4.9%), obese children (age: 9.6 ± 1.3 y, body fat: 40.3 ± 5.2%) and lean adults (age: 23.3 ± 2.4 y, body fat: 12.7 ± 2.9%). The protocol consisted of stepping onto a raised platform (height = 20% of stature) while wearing a weighted vest (resistance = 50% of lean body mass). Participants completed 6 sets of 10 repetitions per leg with a 1-min rest period between sets. Blood samples were obtained at rest preexercise, immediately postexercise and 2 times throughout the 1-hr recovery to analyze possible changes in hormones and metabolites. Children-adult differences included a larger exercise-induced norepinephrine increase in adults vs. children and a decrease in glucagon in children but not adults. Similarities between adults and children were observed for GH-IGF-1 axis responses. Metabolically, children presented with lower glycolytic and increased fat metabolism after exercise than adults did. Obesity in childhood negatively influenced GH, insulin, and glucose concentrations. While adults occasionally differed from children, amount of activated lean mass, not maturation, likely drove these dissimilarities.
Roland van den Tillaar, Erna von Heimburg, and Guro Strøm Solli
challenged the validity of the traditional GXT method by showing that higher VO 2 max values can be achieved with different exercise protocols such as the “free range” test 7 and a decremental exercise test. 8 Furthermore, the introduction of nonmotorized treadmills has made it easier to conduct self
Enda F. Whyte, Nicola Gibbons, Grainne Kerr, and Kieran A. Moran
Context: Determination of return to play (RTP) after sport-related concussion (SRC) is critical given the potential consequences of premature RTP. Current RTP guidelines may not identify persistent exercise-induced neurocognitive deficits in asymptomatic athletes after SRC. Therefore, postexercise neurocognitive testing has been recommended to further inform RTP determination. To implement this recommendation, the effect of exercise on neurocognitive function in healthy athletes should be understood. Objective: To examine the acute effects of a high-intensity intermittent-exercise protocol (HIIP) on neurocognitive function assessed by the Symbol Digits Modality Test (SDMT) and Stroop Interference Test. Design: Cohort study. Setting: University laboratory. Participants 40 healthy male athletes (age 21.25 ± 1.29 y, education 16.95 ± 1.37 y). Intervention: Each participant completed the SDMT and Stroop Interference Test at baseline and after random allocation to a condition (HIIP vs control). A mixed between-within-subjects ANOVA assessed time- (pre- vs postcondition) -by-condition interaction effects. Main Outcome Measures: SDMT and Stroop Interference Test scores. Results: There was a significant time-by-condition interaction effect (P < .001, η 2 = .364) for the Stroop Interference Test scores, indicating that the HIIP group scored significantly lower (56.05 ± 9.34) postcondition than the control group (66.39 ± 19.6). There was no significant time-by-condition effect (P = .997, η 2 < .001) for the SDMT, indicating that there was no difference between SDMT scores for the HIIP and control groups (59.95 ± 10.7 vs 58.56 ± 14.02). Conclusions: In healthy athletes, the HIIP results in a reduction in neurocognitive function as assessed by the Stroop Interference Test, with no effect on function as assessed by the SDMT. Testing should also be considered after high-intensity exercise in determining RTP decisions for athletes after SRC in conjunction with the existing recommended RTP protocol. These results may provide an initial reference point for future research investigating the effects of an HIIP on the neurocognitive function of athletes recovering from SRC.
Susan Vrijkotte, Romain Meeusen, Cloe Vandervaeren, Luk Buyse, Jeroen van Cutsem, Nathalie Pattyn, and Bart Roelands
longer. 1 NFO and OTS are the result of a disbalance between training and recovery. Both psychological and physiological factors interact to create distress that can result in physical and mental fatigue. 2 Meeusen et al 1 , 3 developed a 2-bout exercise protocol for diagnosing NFO and OTS. The 2-bout
Katrina G. Ritter, Matthew J. Hussey, and Tamara C. Valovich McLeod
the types of symptoms and deficits that persist after concussion. Aerobic exercise protocols have been identified as a potentially beneficial treatment for individuals with persistent symptoms who are exacerbated by exertion. Prior research has used aerobic protocols to establish subsymptom baseline
Thiago Oliveira Borges, Nicola Bullock, David Aitken, Gregory R. Cox, and Aaron J. Coutts
ergometers are yet to be established. The aim of this study was to compare the metabolic cost of a standardized kayak incremental exercise protocol performed on different commercially available kayak ergometers. Methods Experimental Design Six athletes undertook an incremental exercise protocol on 3
Stephanie K. Gaskell, Rhiannon M.J. Snipe, and Ricardo J.S. Costa
, nude body mass = 71.6 ± 10.0 kg, 15.4 ± 6.2% body fat mass, and V ˙ O 2 max = 56.5 ± 7.9 ml·kg −1 ·min −1 ) volunteered to participate in this test–retest methodological study. All participants provided written informed consent. Each exercise protocol received approval from the local ethics committee