Acute and chronic testosterone response to blood flow restricted exercise.

The American College of Sports Medicine recommends lifting a weight of at least 70% 1RM to achieve muscular hypertrophy as it is believed that anything below this intensity rarely produces substantial muscle growth. At least part of this recommendation is related to elevated systemic hormones following heavy resistance training being associated with skeletal muscle hypertrophy. Despite benefits of high intensity resistance training, many individuals are unable to withstand the high mechanical stresses placed upon the joints during heavy resistance training. Blood flow restricted exercise offers a novel mode of exercise allowing skeletal muscle hypertrophy at low intensities, however the testosterone response to this exercise has yet to be discussed. The acute and chronic testosterone response to blood flow restricted exercise appears to be minimal when examining the current literature. Despite this lack of response, notable increases in both size and strength are observed with this type of exercise, which seems to support that systemic increases of endogenous testosterone are not necessary for muscular hypertrophy to occur. However, definitive conclusions cannot be made without a more thorough analysis of responses of androgen receptor density following blood flow restricted exercise. It may also be that there are differing mechanisms underlying hypertrophy induced by high intensity resistance training and via blood flow restricted exercise.

Potential safety issues with blood flow restriction training.

The focal point of previous literature was establishing the efficacy of blood flow restriction training with respect to muscular strength, muscular hypertrophy, and muscular endurance. After mounting evidence supporting the efficacy of low-intensity blood flow restriction training, research has shifted to the overall safety of this training modality. The aim of this review was to summarize the research on the overall safety of blood flow restriction training, focusing on the cardiovascular system (central and peripheral), muscle damage, oxidative stress, and nerve conduction velocity responses compared with those observed with regular exercise. Although still sparse, the blood flow restriction training research thus far is promising with respect to safety outcomes. Individuals respond similarly to blood flow restriction training and to regular exercise; however, longer term studies are required to better understand the chronic effects of low-intensity blood flow restriction training and possible safety issues.

The perceptual responses to occluded exercise.

The purpose was to determine repetitions to failure and perceptual responses to exercise with and without occlusion. 15 subjects participated in a randomized crossover study of 3 trials. The first determined one repetition maximum (1RM) on the leg extension. Subjects were then assigned to an occlusion (OCC) or control (CON) group. After trial 2, subjects crossed over to the opposite trial. Knee wraps (KW) were placed around the upper thigh of each leg during OCC. Subjects completed 2 sets of leg extensions to failure at 30% 1RM, with 30 s rest between sets. Ratings of perceived exertion (RPE) and pain (P) were taken following each set. Data were analyzed using paired sample t-tests with an alpha level of 0.01. OCC repetitions were lower for the first and second set compared to CON (p=0.001). Total work completed was significantly lower with OCC compared to CON (p=0.001). OCC RPE were higher for both the first (p=0.01) and second set (p=0.003) compared to CON. P was not different following one set but was higher with OCC over CON following the second (p=0.009). In conclusion, KW provide an OCC stimulus allowing failure to occur sooner. However, the higher perceptual responses with OCC may limit its application to the highly motivated.

Athletic Trainers as HIV/AIDS Educators for Athletes.

HIV/AIDS continues to spread among the population at large. The age group 20 through 29 is the fastest growing demographic group in terms of AIDS diagnosis. This study examined a specific subgroup of that population: male and female college athletes. Subjects were 821 scholarship basketball players from 53 NCAA institutions across the nation. A survey instrument required respondents to identify common sources of HIV/AIDS information and preferred instructional formats for HIV/AIDS education. Mass media (92.4%), parents (62.2%), and teammates/peers (54.8%) were most commonly identified. Athletic trainers and team physicians were identified by 32.2% and 43.4% of the sample, respectively. The athletes indicated preference for video presentations (66.5%), small group discussions (58.8%), and question and answer sessions with expert panels (52.4%) as the most preferred instructional formats. Athletic trainers and team physicians can use the information presented in this paper to enhance their important roles in HIV/AIDS education for student athletes.

Influence of music on Wingate Anaerobic Test performance.

While several studies have investigated the effects of music on cardiovascular endurance performance and perceived exertion during exercise of moderate intensity, few studies have investigated such effects on supramaximal exercise bouts. The purpose of the present study was to assess whether music affects performance on the Wingate Anaerobic Test. Each of the 12 men and 3 women were required to report to the laboratory on two occasions, once for tests in the music condition and once for tests in the nonmusic condition. Conditions were randomly ordered. All music selections were set at the same tempo. On each test day subjects performed a series of three Wingate Anaerobic Tests with 30-sec. rests in between. On Test 3 subjects were asked to continue pedaling until fatigued. Mean Power Output, Maximum Power Output, Minimum Power Output, and Fatigue Index were compared between conditions for each test using a repeated-measures analysis of variance. Time to fatigue on Trial 3 compared by analysis of variance gave no significant differences between conditions for any measures.

Effects of an external nasal dilator strip on differentiated ratings of perceived exertion.

17 college-age subjects performed two 20-min. runs at 65% of maximal oxygen consumption. Randomized trials were conducted with an external nasal dilator strip or without. Subjects were polled every 5 min. for over-all rating of perceived exertion, central rating of perceived exertion, and local rating of perceived exertion. The use of an external nasal dilator strip did not significantly lower any of the three

Sarcopenia: An emphasis on occlusion training and dietary protein.

Demographics reveal that the world's population aged 60 years and older will triple from 600 million in 2000 to more 2 billion by the year 2050. To remain independent and healthy, an important factor to consider is the maintenance of skeletal muscle, as the elderly seem to become prone to a progressive loss of skeletal muscle with aging, termed sarcopenia. Interventions should focus on resistance training and optimal nutrition. Low intensity occlusion training may provide a mode of resistance training more applicable to the elderly, due to the lower loads used. Furthermore, an emphasis must be placed on high quality protein adequately distributed throughout the day to maximize protein synthesis. The use of drug therapy may be of some benefit, but it appears exercise and diet likely plays a more prominent role in the preservation of muscle mass and strength than administration of synthetic hormones.