Measurements of Heart Rate and Accelerometry to Determine the Physical Activity Level in Boys Playing Paintball

International Journal of Exercise Science 6(3) : 199-207, 2013. Paintball is a popular recreational sport played by 3.655 million Americans and may be sufficient physical activity to promote health. Paintball has been played as an organized sport since the 1980’s and is essentially a game of tag, except instead of touching an opponent by hand opponents are tagged by shooting them with a paintball that leaves a mark indicating who has been eliminated. A previous evaluation of paintball as physical activity had 13 subjects undergo a VO2max test to develop a heart rate (HR) /oxygen consumption relationship, and it was observed that heart rates during paintball were 68-73% of the measured maximal HR. The present study used accelerometry and HR monitors to evaluate the quantity and intensity of physical activity in boys playing paintball. Eleven boys (12.7 ± 1.0 y, 51.5 ± 11.3 kg, 161.8 ± 10.1 cm) engaged in a VO2max test to develop a HR/oxygen consumption correlation. On a separate day the boys played 7 games of outdoor paintball while wearing a HR monitor and accelerometer. The boys played paintball for 11.5 ± 6.2 minutes/game for a total of 80.6 ± 10.0 minutes of game play. Average HR during paintball play was 129.6 ± 6.6 beats/min, representing 39.9 ± 12.9% VO2max. Based on accelerometry, the boys accumulated 63.2 ± 15.6 minutes of moderate intensity activity and 2.6 ± 2.8 minutes of vigorous activity during paintball. These data suggest that playing paintball may be considered as physical activity that is \u3e 3 METs, and thus health promoting

Effects of Energy Drinks on Metabolism at Rest and During Submaximal Treadmill Exercise in College Age Males.

Energy drinks are widely available and popular among athletes and non-athletes. However, the effects of energy drinks on resting and exercise energy expenditure and metabolism remain largely unknown. On four separate occasions, baseline measurements of resting metabolic rate (RMR) and Respiratory Exchange Ratio (RER) were obtained in ten healthy males (21.4 ± 1.6 y, 77.60± 7.5 kg, 180.0 ± 7.1 cm). Then, in a randomly assigned cross-over design, the subjects consumed 473 ml of one of three commercially available energy drinks or a placebo and then RMR and RER were measured 1 hour later. The subjects then engaged in 15 minutes of treadmill exercise at 50% of V02max, during which RER and oxygen consumption (VO2) were measured. RMR was not changed by placebo, but increased (P\u3c0.05, means ± se) above baseline by 10 ± 2.5%, 15.0 ± 2.9%, and 15.3 ± 2.9%, following Energy Drink One, Energy Drink Two, and Energy Drink Three (respectively) with no differences between energy drinks. RER was reduced below baseline (P\u3c0.05) by 4.9 ± 1.5% in the placebo and increased (P\u3c0.05) above baseline by 12.8 ± 1.8%, 9.6 ± 1.3%, and 9.0 ± 1.3% following Energy Drink One, Energy Drink Two, and Energy Drink Three (respectively) with no differences between energy drinks. Oxygen consumption and RER during submaximal exercise were not different between placebo, Energy Drink One, Energy Drink Two, or Energy Drink Three. These data indicate that energy drink consumption increases RMR and carbohydrate use at rest, but metabolism during submaximal exercise remains unchanged

Design, fabrication, and characterization of a micro fuel processor

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, February 2008.Includes bibliographical references (p. 171-174).The development of portable-power systems employing hydrogen-driven solid oxide fuel cells continues to garner significant interest among applied science researchers. The technology can be applied in fields ranging from the automobile to personal electronics industries. In order for fuel cell systems to outperform batteries, a method of chemically converting high-energy-density combustible fuels to hydrogen while maintaining high thermal efficiency must be developed. This thesis focuses on developing microreaction technology that minimizes thermal losses during the conversion of fuels - such as light end hydrocarbons, their alcohols, and ammonia - to hydrogen. Critical issues in realizing high-efficiency devices capable of operating at high temperatures have been addressed: specifically, thermal management, the integration of materials with different thermophysical properties, and the development of improved packaging and fabrication techniques. A new fabrication scheme for a thermally insulated, high temperature, suspended-tube microreactor has been developed. The new design improves upon a monolithic design proposed by Leonel Arana. In the new modular design, a high-temperature reaction zone is connected to a low-temperature package via the brazing of pre-fabricated, thin-walled glass tubes. The design also replaces traditional deep reactive ion etching (DRIE) with wet potassium hydroxide (KOH) etching, an economical and time-saving alternative. A glass brazing method that effectively accommodates the difference in thermal expansion between the silicon reactor and the glass tubes has been developed. The material used in this procedure is stable at temperatures up to 710 °C. Autothermal combustion of hydrogen, propane, and butane in excess oxygen has been demonstrated in ambient atmosphere and under vacuum. Hot spot temperatures of up to 900 °C have been measured during autothermal combustion of propane in ambient and vacuum conditions.(cont) Experimental temperature measurements have been compared to steady-state temperature estimates, and show good agreement. Finally, a computational fluid dynamics (CFD) model has been developed to study the heat transfer properties of the microreactor. Using simplified reaction schemes from the literature, the model has successfully reproduced the results observed in the laboratory.by Brandon S. Blackwell.Ph.D

Rare Event Extinction on Stochastic Networks

We consider the problem of extinction processes on random networks with a given structure. For sufficiently large well-mixed populations, the process of extinction of one or more state variable components occurs in the tail of the quasi-stationary probability distribution, thereby making it a rare event. Here we show how to extend the theory of large deviations to random networks to predict extinction times. In particular, we use the theory to find the most probable path leading to extinction. We apply the methodology to epidemic models and discover how mean extinction times scale with epidemiological and network parameters in Erdos-Renyi networks. The results are shown to compare quite well with Monte Carlo simulations of the network in predicting both the most probable paths to extinction and mean extinction times.Comment: 5 pages 6 figure

Wii, Kinect, & Move. Heart Rate, Oxygen Consumption, Energy Expenditure, and Ventilation due to Different Physically Active Video Game Systems in College Students.

International Journal of Exercise Science 7(1) : 22-32, 2014. Nintendo Wii, Sony Playstation Move, and Microsoft XBOX Kinect are home video gaming systems that involve player movement to control on-screen game play. Numerous investigations have demonstrated that playing Wii is moderate physical activity at best, but Move and Kinect have not been as thoroughly investigated. The purpose of this study was to compare heart rate, oxygen consumption, and ventilation while playing the games Wii Boxing, Kinect Boxing, and Move Gladiatorial Combat. Heart rate, oxygen consumption, and ventilation were measured at rest and during a graded exercise test in 10 males and 9 females (19.8 ± 0.33 y, 175.4 ± 2.0 cm, 80.2 ± 7.7 kg,). On another day, in a randomized order, the participants played Wii Boxing, Kinect Boxing, and Move Gladiatorial Combat while heart rate, ventilation, and oxygen consumption were measured. There were no differences in heart rate (116.0 ± 18.3 vs. 119.3 ± 17.6 vs. 120.1 ± 17.6 beats/min), oxygen consumption (9.2 ± 3.0 vs. 10.6 ± 2.4 vs. 9.6 ± 2.4 ml/kg/min), or minute ventilation (18.9 ± 5.7 vs. 20.8 ± 8.0 vs. 19.7 ± 6.4 L/min) when playing Wii boxing, Kinect boxing, or Move Gladiatorial Combat (respectively). Playing Nintendo Wii Boxing, XBOX Kinect Boxing, and Sony PlayStation Move Gladiatorial Combat all increase heart rate, oxygen consumption, and ventilation above resting levels but there were no significant differences between gaming systems. Overall, playing a “physically active” home video game system does not meet the minimal threshold for moderate intensity physical activity, regardless of gaming system

Resistance Training and Weight Management: Rationale and Efficacy

In addition to the impact of normal ageing on body composition, increasing levels of sedentariness reduce an individual’s ability to mobilise fat, resulting in an altered body composition characterised by increased fat mass, and more specifically an increased total and abdominal fat, and reduced muscle mass. While exercise, and aerobic exercise in general, has been promoted as a means to maintaining an appropriate body weight, aerobic exercise should not be considered as the golden standard to do so. This is because resistance training (RT) has an unsurpassed ability to improve lean mass along with other simultaneous improvements in multiple body composition parameters. An increased muscle mass is essential in that it is the amount of exercising muscle that determines the magnitude of lipolysis (fatty acid release from adipocytes) during exercise. In addition, an increased muscle mass results in an elevated basal metabolic rate (BMR) and resting metabolic rate (RMR), effectively increasing the amount of energy or calories utilised even at rest. RT is especially useful in the general population for weight management in that the ideal form of RT required for improvements in body composition is of moderate intensity, which reduces the risk of injury and improves adherence

Physical Activity and Health Promotion: A Public Health Imperative

Continuing epidemiological and clinical studies have accumulated evidence that appropriate regular physical activity (PA) results in significant health benefits and can even prevent and treat many diseases like cardiovascular diseases, obesity, diabetes, musculoskeletal problems, stress, anxiety, and depression. These benefits are universal to all populations and age groups making physical activity a critical component in reducing many of the leading causes of global mortality. Additional benefits have also been found to follow an expanding quantity and quality of PA through the proper manipulation of the exercise design (i.e., frequency, intensity, duration, and mode). Global health benefits are achievable through physical activity, but this requires competent health professionals able to prescribe appropriate physical activity to their clients, patients, and communities to ensure engagement in increasing their PA levels and thus contribute to their own well-being and the prevention of the main non-communicable chronic diseases (NCDs)

Importance of Resistance Training in the Management of Cardiovascular Disease Risk

Contrary to the longstanding taboo of resistance training (RT) as a therapeutic treatment, RT has been gaining importance as a safe therapeutic option in the management of numerous diseases. Although exercise has well-documented health benefits on cardiovascular disease (CVD), the benefit of RT on CVD risk factors is not yet as widely prescribed as other modes of exercise. Due to its efficacy in the management of CVD, RT should be regarded as a complementary therapeutic treatment rather than a substitute to other modes of exercise therapy. While it is clear that RT can result in an attenuation of CVD risk, the various RT design options related to intensity and volume and how they impact on CVD risk, especially in different populations (i.e. children, elderly, women) is not yet well documented. This chapter will discuss the physiological phenomenon and benefits of RT as a therapeutic intervention aiming to manage CVD risk

Dark-state enhanced loading of an optical tweezer array

Neutral atoms and molecules trapped in optical tweezers have become a prevalent resource for quantum simulation, computation, and metrology. However, the maximum achievable system sizes of such arrays are often limited by the stochastic nature of loading into optical tweezers, with a typical loading probability of only 50%. Here we present a species-agnostic method for dark-state enhanced loading (DSEL) based on real-time feedback, long-lived shelving states, and iterated array reloading. We demonstrate this technique with a 95-tweezer array of $^{88}$Sr atoms, achieving a maximum loading probability of 84.02(4)% and a maximum array size of 91 atoms in one dimension. Our protocol is complementary to, and compatible with, existing schemes for enhanced loading based on direct control over light-assisted collisions, and we predict it can enable close-to-unity filling for arrays of atoms or molecules

The impact of modified exercise and relaxation therapy on chronic lower back pain in office workers: a randomized clinical trial

This study aimed to evaluate the effectiveness of a modified package of exercise therapy combined with relaxation on pain intensity, range of motion (ROM), anxiety, and quality of life (QoL) in office workers with chronic lower back pain. In this clinical trial, 72 office workers aged 20 to 50 years with chronic low back pain were randomized to one of four groups including; group 1, exercise therapy; group 2, psychotherapy (relaxation therapy); group 3, modified protocol (exercise therapy followed by relaxation therapy); group 4, control group (no intervention). Participants exercised 3 times weekly for 6 weeks for 40-45 min of exercise/relaxation. Pain intensity, ROM, anxiety, and QoL were evaluated at baseline, 6 weeks, and 12 weeks after the end of the intervention. Re-sults showed significant decreases in pain intensity and anxiety in the three experimental groups compared to the control group. The three intervention groups indicated a significant decrease in pain intensity and anxiety after 6 and 12 weeks. ROM significantly improved in the exercise therapy and the modified protocol over time (after 6 and 12 weeks). A significant difference in QoL was found between the groups, with the greatest improvement found in the psychotherapy and modified protocol groups. This therapeutic package (including exercise movements and psychological interventions) was found to have a superior effect on pain intensity, ROM, anxiety, and QoL after 6 and 12 weeks compared to other interventions (only exercise and psychotherapy)