スポーツ医学およびドーピング研究ジャーナル

Concussion is a traumatically induced transient disturbance of brain function and involves a complex pathophysiological process at the less-severe end of brain injury spectrum. Sport-Related Concussion (SRC) is increasingly been recognized as an individual entity globally. Whilst the neurological effects of SRC are well known, neuropsychological testing and its implications in SRC remain to elude sports medicine professionals with a dilemma of to do or not do? This editorial aimed to address this issue speculating from an evidence-informed viewpoint. An overview of definition, history and development of neuropsychological testing, its uses and issues related to its interpretation are discussed in this paper, with implications for future research.

Determining the oxygenation level of skeletal muscle is an effective non-invasive method of evaluating its physiological changes. Nevertheless, the relationship between muscle fiber composition and intramuscular oxygenation is still unclear. In the present study we examined the differences in muscle fiber composition and their relationship to muscle oxygenation levels by comparing power lifters (Training group), who regularly engaged in muscular resistance training, with ordinary healthy people (Control group). The vastus lateralis muscle oxygenation level was measured via near infrared continuous wave spectroscopy, and muscle tissues were collected and used for histochemical analyses in order to calculate muscle fiber compositions. When the rate of decrease in muscle oxygenation after performing a single squat at 50 and 80% of the participants’ maximal lifting weight (MLW) was examined, the rate of decrease was significantly higher at 80% of MLW than at 50% of MLW in Training group, and was significantly higher in the Training group than in the Control group. Moreover, after performing multiple squat movements at 80% of MLW, compared with the Control group, the Training group showed a significant delay in the time it took for their muscle oxygenation level to recover to 50% of its original level at resting time (T_1/2). A significant correlation between the occupancy of Type IIa fiber and T_1/2, or between an average cross-sectional area of muscle fibers and T_1/2 was noted. The present study demonstrated that in the Training group, in a cross-sectional area of Type IIa fiber that had increased, the decreased muscle oxygenation level due to performing squat exercises exhibited a delay in recovery at the resting time, suggesting that the amount of oxygen consumption was increased in the Training group because the crosssectional area of Type IIa fiber was larger, compared with the Control group.

Background: The purpose of this study was to determine if differences in strength gain are apparent following resistance training at two different exercise volumes (2-sets versus 3-sets).

Methods: Seven men (age=21.6 ± 1.5) completed the study. Each subject trained one leg in the leg extension exercise using two sets and trained the other using three sets. Subjects were randomly assigned to two groups then treatments were randomly assigned to groups to minimize bias: one group assigned two sets right leg and three sets left leg (3L 2R; n = 3), one group assigned three sets right leg and two sets left leg (3R 2L; n=4). One repetition maximum (1RM) was determined for each leg of each participant for the leg extension prior to the three sessions per week and six week duration training program. Each set included in training consisted of six repetitions at a workload of 80% 1RM during each session. 1RM was tested after 2 and 4 weeks allowing for training workloads to be adjusted to 80% of current 1RM to apply the principle of progression. Results: Significant differences were apparent when comparing pre- and post-training absolute 1RM measures for both the two set and three set legs (p<0.05). There was a significant difference in magnitude of change between the two set and three set legs, 12.6 kg versus 19.4 kg respectively (p=0.02). Conclusion: While six weeks of either two or three sets of the leg extension exercise training both significantly increase quadriceps strength, the three set configuration creates a significantly larger magnitude of change compared to two sets.

Resistance Exercise (RE) is a widely practiced activity both in leisure time and in training periods for competitive athletes. Recent advanced in molecular biology and muscle physiology has elucidated some of the mechanisms that regulate muscle growth. As a result of these biochemical advances, an increased number of supplements claiming to enhance adaptations to Resistance exercise have become available. Essentially, the aim of these supplements is to influence protein synthesis and therefore gradual protein accretion leading to increased muscle size and strength. The aim of this review is to discuss the most commonly consumed supplements associated with RE and make recommendations with regards to timing, volume and combinations of supplementations.

Athletes and recreationally resistance-trained individuals often use protein supplements in an attempt to maximize their training gains and performance. Because of the high bioavailability and solubility and its higher proportion of essential amino acids including Leucine, whey protein extract has been proposed as the best optimal form of protein for strength and power athletes. The objective of this review is to examine the current evidence for the efficacy of whey protein containing supplements to optimize strength training adaptation and outcomes for regular resistance training practitioners.

A limited numbers of studies have reported positive effects of whey protein containing supplements (including those with carbohydrate and creatine) for optimizing the anabolic responses and adaptations process in resistancetrained individuals.

In order to promote a more anabolic environment and maximize muscle protein synthesis along the day, an eating pattern behavior involving frequents meals (every 3 to 5 h) containing 17 to 20 g of high quality protein (200 to 250 mg/ kg) providing 8 to 10 g of EAA (90 to 110 mg/kg) and about 2 g of Leucine (20 to 25 mg/kg) have been recommended. Special attention should be given to the periworkout hours where the ingestion of whey proteins combined with carbohydrates, creatine monohydrate (0.1 g/kg/d) and other proteins sources such as casein before, during and after workout have been shown to improve training adaptations and enhance the recovery process. However, when considering that the training conditions (workout volume, organization, number of exercises) used in the available studies are substantially different than what athletes actually perform. Optimal whey protein supplementation protocols need to specifically be based on the regular resistance training workout organization and would probably need to consider other doses and timing strategies than what is currently recommended.