Climate Change, Air Pollution, and Physical Inactivity: Is Active Transportation Part of the Solution?

Active transportation is defined as self-propelled, human-powered transportation modes, such as walking and bicycling. In this article, we review the evidence that reliance on gasoline-powered transportation is contributing to global climate change, air pollution, and physical inactivity and that this is harmful to human health. Global climate change poses a major threat to human health and in the future could offset the health gains achieved over the last 100 yr. Based on hundreds of scientific studies, there is strong evidence that human-caused greenhouse gas emissions are contributing to global climate change. Climate change is associated with increased severity of storms, flooding, rising sea levels, hotter climates, and drought, all leading to increased morbidity and mortality. Along with increases in atmospheric CO2, other pollutants such as nitrogen dioxide, ozone, and particulate matter (e.g., PM2.5) are released by combustion engines and industry, which can lead to pulmonary and cardiovascular diseases. Also, as car ownership and vehicle miles traveled have increased, the shift toward motorized transport has contributed to physical inactivity. Each of these global challenges has resulted in, or is projected to result in, millions of premature deaths each year. One of the ways that nations can mitigate the health consequences of climate change, air pollution, and chronic diseases is through the use of active transportation. Research indicates that populations that rely heavily on active transportation enjoy better health and increased longevity. In summary, active transportation has tremendous potential to simultaneously address three global public health challenges of the 21st century.

Portable open-circuit spirometry systems.

BACKGROUND: The purpose of this review is to describe the evolution of portable open-circuit spirometry systems, and discuss their validity, reliability, and principles of operation. METHODS: Eleven devices were selected for review: the Oxylog, Aerosport KB1-C, Cosmed K2, Cosmed K4RQ, Cosmed K4b2, MetaMax I, MetaMax II, Metamax3B/VmaxST, Medgraphics VO2000, Oxycon Mobile I and Oxycon Mobile II. The validity (compared to the Douglas bag method [DBM]) and reliability of each device for measuring VO2 was summarized. RESULTS: Mean differences in resting measurements of VO2 were within ±0.05 L/min for all devices except one (difference of 0.17 L/min). When compared to the DBM, VO2 differences for all devices ranged from 0.01 L/min to 0.29 L/min during submaximal intensity exercise and from 0.01 L/min to 0.36 L/min during vigorous/maximal intensity. During submaximal and maximal intensities, ICC ranged from 0.66-0.99 and CV ranged from 2.0-14.2%. Of these devices, four used breath-by-breath technology and six used micro-proportional sampling technology. Validity and reliability of devices did not seem to differ between methods of gas collection. CONCLUSIONS: Of the three commercially available devices in 2015, all were found to be reliable. Two of the three systems (Cosmed K4b2 and Oxycon Mobile II) provided valid estimates of VO2 (mean values within ±0.10 L/min of DBM) during rest, and submaximal and maximal intensities, while the MetaMax3B slightly overestimated VO2, particularly at maximal exercise.

Effect of the E3 Fitness Grips on Running Economy.

The purpose of this study was to evaluate the effect of the E3 Fitness Grips (BioGrip, Inc., Rancho Cordova, CA) on running economy, as measured by oxygen uptake (VO2), and heart rate (HR) during submaximal treadmill running. Eleven subjects, seven female and four male, completed a submaximal running test on a treadmill while VO2 and HR were measured continuously. After achieving steady-state at a speed and grade that elicited a VO2 equivalent to 70% VO2max, the subjects ran for five minutes holding the E3 Fitness Grips (G) and five minutes without the grips (NG). The tests were counterbalanced so half of the subjects held the grips first and half completed the NG condition first. The difference in VO2 and HR between the G and NG conditions were compared to determine the effect on running economy. The mean VO2 (33.2±4.6 vs. 33.2±4.6 ml·kg-1·min-1, p=0.96) and mean HR (172.0±8.9 vs. 172.8±8.9 beats·min-1, p=0.38) were not significantly different between the G and NG conditions during submaximal running. These findings suggest that the E3 Fitness Grips do not significantly alter running economy, as measured by VO2, or HR during submaximal treadmill running.

A preliminary study of one year of pedometer self-monitoring.

BACKGROUND: Long-term pedometer monitoring has not been attempted. PURPOSE: The purpose of this project was to collect 365 days of continuous self-monitored pedometer data to explore the natural variability of physical activity. METHODS: Twenty-three participants (7 men, 16 women; M age = 38 +- 9.9 years; M body mass index = 27.7 +- 6.2 kg/m2) were recruited by word of mouth at two southern U.S. universities. Participants were asked to wear pedometers at their waist during waking hours and record steps per day and daily behaviors (e.g., sport/exercise, work or not) on a simple calendar. In total, participants wore pedometers and recorded 8,197 person-days of data (of a possible 8,395 person-days, or 98%) for a mean of 10,090 +- 3,389 steps/day. Missing values were estimated using the Missing Values Analysis EM function in SPSS, Version 11.0.1. RESULTS: A mean of 10,082 +- 3,319 steps/day was computed. Using the corrected data, differences in steps/day were significant for season (summer > winter, F = 7.57, p = .001), day of the week (weekday > weekend, F = 3.97, p = .011), type of day (workday vs. nonworkday, F = 9.467, p = .008), and participation in sport/exercise (day with sport/exercise > day without sport/exercise, F = 102.5, p < .0001). CONCLUSIONS: These data suggest that surveillance should be conducted in the spring/fall or that an appropriate correction factor should be considered if the intent is to capture values resembling the year-round average.