Despite the popularity of resistance training (RT), an accurate method for quantifying its metabolic cost has yet to be developed. We applied indirect calorimetry during bench press (BP) and parallel squat (PS) exercises for 5 consecutive minutes at several steady state intensities for 23 (BP) and 20 (PS) previously trained men. Tests were conducted in random order of intensity and separated by 5 minutes. Resultant steady state VO2 data, along with the independent variables load and distance lifted, were used in multiple regression to predict the energy cost of RT at higher loads. The prediction equation for BP was Y' = 0.132 + (0.031)(X1) + (0.01)(X2), R2 = 0.728 and S(xy) = 0.16; PS can be predicted by Y' = -1.424 + (0.022)(X1) + (0.035)(X2), R2 = 0.656 and S(xy) = 0.314; where Y' is VO2 X1 is the load measured in kg and X2 is the distance in cm. Based on a respiratory exchange ratio (RER) of 1.0 and a caloric equivalent of 5.05 kcal x L(-1), VO2 was converted to caloric expenditure (kcal x min(-1)). Using those equations to predict caloric cost, our resultant values were significantly larger than caloric costs of RT reported in previous investigations. Despite a potential limitation of our equations to maintain accuracy during very high-intensity RT, we propose that they currently represent the most accurate method for predicting the caloric cost of bench press and parallel squat.
summary Cordyceps sinensis is a potentially ergogenic herb that gained popularity after the Chinese women's team credited it for their world-record performances at the 1993 World Track and Field Championships. Since then, a few peer-reviewed investigations have been published, but results of these investigations have been equivocal, with two human studies claiming an ergogenic effect and three human studies failing to find an effect. At this time, it is premature to conclude that Cordyceps sinensis does or does not possess ergogenic properties.
Agility training (AT) has recently been instituted in several military communities in hopes of improving combat performance and general fitness. The purpose of this study was to determine how substituting AT for traditional military physical training (PT) influences physical and cognitive performance. Forty-one subjects undergoing military technical training were divided randomly into 2 groups for 6 weeks of training. One group participated in standard military PT consisting of calisthenics and running. A second group duplicated the amount of exercise of the first group but used AT as their primary mode of training. Before and after training, subjects completed a physical and cognitive battery of tests including V[Combining Dot Above]O2max, reaction time, Illinois Agility Test, body composition, visual vigilance, dichotic listening, and working memory tests. There were significant improvements within the AT group in V[Combining Dot Above]O2max, Illinois Agility Test, visual vigilance, and continuous memory. There was a significant increase in time-to-exhaustion for the traditional group. We conclude that AT is as effective or more effective as PT in enhancing physical fitness. Further, it is potentially more effective than PT in enhancing specific measures of physical and cognitive performance, such as physical agility, memory, and vigilance. Consequently, we suggest that AT be incorporated into existing military PT programs as a way to improve war-fighter performance. Further, it seems likely that the benefits of AT observed here occur in various other populations.
Despite the popularity of resistance training (RT), an accurate method for quantifying its metabolic cost has yet to be developed. We applied indirect calorimetry during bench press (BP) and parallel squat (PS) exercises for 5 consecutive minutes at several steady state intensities for 23 (BP) and 20 (PS) previously trained men. Tests were conducted in random order of intensity and separated by 5 minutes. Resultant steady state VO2 data, along with the independent variables load and distance lifted, were used in multiple regression to predict the energy cost of RT at higher loads. The prediction equation for BP was Y′ = 0.132 + (0.031)(X1) + (0.01)(X 2), R2 = 0.728 and Sxy = 0.16; PS can be predicted by Y′ = -1.424 + (0.022)(X1) + (0.035)(X 2), R2 = 0.656 and Sxy = 0.314; where Y′ is VO2, X1 is the load measured in kg and X 2 is the distance in cm. Based on a respiratory exchange ratio (RER) of 1.0 and a caloric equivalent of 5.05 kcal·L-1, VO 2 was converted to caloric expenditure (kcal·min -1). Using those equations to predict caloric cost, our resultant values were significantly larger than caloric costs of RT reported in previous investigations. Despite a potential limitation of our equations to maintain accuracy during very high-intensity RT, we propose that they currently represent the most accurate method for predicting the caloric cost of bench press and parallel squat.
AbstractConventional dietary guidelines put forth by health care institutions and providers for the past 40 years have stressed the importance of reducing the amount of dietary fat consumed. Such a diet is purported to mitigate metabolic risk factors and optimize the ability to achieve or maintain a healthy body weight. However, over the past 35 years obesity rates in the United States have risen dramatically though the level of dietary fat consumed by U.S. adults has fallen. This review examines the potential reasons for this paradox. Various meta-analyses, controlled trials, and cohort studies have demonstrated that reducing dietary fat intake provides for very little weight loss unless accompanied by equal or greater reductions in total energy intake. Due to both psychological (e.g., the tendency for people to eat more of what they consider low fat) and physiological (e.g., the low satiety that accompanies carbohydrate intake) factors, reducing total caloric intake while simultaneously reducing fat intake is a difficult challenge. Further, reductions in total carbohydrate intake, increases in protein intake, and adoption of a Mediterranean diet seem to be more effective in inducing weight loss than reductions in fat intake. Traditional claims that simply reducing dietary fat will improve metabolic risk factors are also not borne out by research. There is some evidence that replacing dietary saturated fat with unsaturated fat may improve metabolic risk factors, but that research is not conclusive.Teaching Points:• Over the past 40 years, Americans have decreased the percentage of calories they get from dietary fat while rates of overweight and obesity have risen dramatically.• It appears that a decrease in total dietary fat in ad libitum diets may induce a very small decrease in body weight.• Evidence suggests that reductions in total dietary fat intake often occur in conjunction with an increase in total caloric intake.• It seems reasonable to conclude that guiding the public to simply reduce dietary fat intake is an ineffective method to mitigate the rise in obesity and improve public health. Key words: dietary fatobesitymacronutrient ratiocardiovascular disease
A procedure has been devised for the specific determination of catechol in cigarette-smoke condensates. This procedure should also be applicable to the determination of catechol in other materials resulting from pyrolytic or combustion processes.As the catechol is isolated without recourse to the formation of a derivative, no interference is encountered as a result of the presence of guaiacol or similar compounds. Avoidance of the use of alkaline conditions throughout the procedure has permitted reproducible and high recoveries.
Caffeine ingestion has been demonstrated to increase physical performance in some situations. This study examined the ability of a commercial energy drink containing caffeine to enhance acceleration tolerance and strength under G load.Eight experienced centrifuge subjects completed three separate experimental acceleration exposures following ingestion of 11.5 ml x kg(-1) bodyweight of (1) a commercial energy drink, providing 5.0 mg caffeine/kg bodyweight; (2) a commercial energy drink without caffeine; or 3) a placebo. The acceleration exposures consisted of a relaxed gradual onset run to peripheral light loss, a rapid onset run to 6 G for 15 s, and a simulated air combat maneuver (SACM) run of repeated alternations between 4.5 G for 15 s and 7 G for 15 s until volitional exhaustion.Relaxed G tolerance was 13% higher under the caffeinated energy drink session, whereas SACM duration did not differ among the drink conditions. Hip adductor muscle strength was 37% lower during the placebo session than during the other two sessions.Consumption of a caffeine-based energy drink may enhance relaxed G tolerance and may increase strength, but does not impact acceleration tolerance duration.
The Combat Controller (CCT) "pipeline" spans nearly 24 months taking US Air Force trainees from basic skills to combat-ready battlefield airmen. It requires an extremely high level of motivation, physical fitness, and mental toughness. Historically, the wash-out rate in this training has averaged almost 75% due to a high rate of overuse injuries, failure to meet academic and physical standards, and self-initiated eliminations. A longitudinal study was designed to identify the physiological, psychological, or demographic performance characteristics that determine successful progression through the CCT training program. PURPOSE: The purpose of this study was to identify psychological characteristics associated with successful trainees in the CCT pipeline. METHODS: We tested 106 CCT trainees (23.6 + 3.0 yr old) using the International Personality Item Pool (IPIP) and the Mental Toughness Questionnaire (MTQ) near the mid-point of a 24-month program. The IPIP compared levels of five broad personality domains (extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience) to other individuals of the same sex and age in the United States. The MTQ assessed trainees' ability to withstand pressure in a range of environments. This 48-question test is comprised of four subscales: challenge, control, commitment, and confidence. RESULTS: The IPIP found that trainees fell within the highest 30% of population scores for extraversion and conscientiousness. The majority of trainees (60-70%) had scores comparable to the lowest 30% of US males in neuroticism and openness to experience. The findings from the MTQ supported the findings from the IPIP that CCT trainees possess personality types which are able to deal with very stressful situations in a range of workplace environments. CONCLUSION: While IPIP and MTQ scores cannot describe the exact personality of trainees or how much pressure a trainee can handle, they can provide an estimation of the attributes that make up a successful combat controller. They also provide a reference for recruiting standards and psychological training/assessment during the pipeline, which has the potential to increase the number of successful graduates and reduce costs associated with student attrition. "Approved for Public Release: Distribution Unlimited"
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