Table 2.

Studies reporting objectively measured physical activity in adults in relation to public transport use.

Study Characteristics		Methodology					Outcome
Author, Year, Country,	Research Question	Public Transport Measure		Physical Activity Measure	Occupational/Leisure-Time Physical Activity Separated in Final Analyses	Confounders Measured	Result
Study Design,
Sample Size/Demographic
Lachapelle, U et al. (2011) [15]	Relationship between commuting by public transport and objectively measured moderate intensity physical activity.	Reported % of all work commute trips taken by public transport. 3 groups:		Mean daily minutes of accelerometer measured moderate intensity physical activity.	Self report measures of occupational/ leisure-time physical activity did not confound results.	(1) Neighbourhood walkability, enjoyment of physical activity, demographics.	(1) Frequent public transport users accumulated significantly more (+8 mins) moderate-intensity physical activity daily compared with non-public transport users.
USA
Cross-sectional		-non public transport user
n = 1,237		-infrequent public transport user(<50% commutes by public transport)
20–65 years old working outside home		-frequent public transport user(≥50% commutes by public transport)
Besser, LM et al. (2005) [18]	Estimate the daily level of physical activity obtained by Americans solely by walking to/from transit.	Only measured walking in transit users so no public transport measure.		Minutes spent walking to/from transit in a 24 h period.	Only walking to/from transit measured.	(1) Uncontrolled	(1) People who walk to/from transit accumulate 24.3 mins of mean walking time/day.
USA
Cross-sectional
n = 3,312
18+ years who walked to/from transit on day of measurement						(2) Stratified for transit type, demographics, population density, car ownership.	(2) 29% of transit users achieve ≥ 30 minutes walking to/from transit daily.
Edwards, R et al. (2008) [16]	Is the additional walking associated with mass transit use large enough to reduce obesity & health care costs? (by estimating additional walking associated with public transport use).	“Public transit user” = anyone who reports using public transport for any reason on assigned travel day.		Time spent walking on assigned travel day for any purpose.	no	(1) Demographics, number of household vehicles, own home, census region fixed effects.	(1) Public transport use associated with significantly more (8–10 mins) additional walking per day.
USA
Cross-sectional
n = 28,771
18+ years old from National Household travel survey
Evans, A et al. (2009) [19]	Focus is on rail and road safety.	Only examined walking in rail users so no public transport measure.		Self report distance walked to surface railway stations over 7 consecutive reporting days.	Only measured walking to train stations.	no	Brits walk an average of 0.905 km per journey on journeys with surface rail as the main mode.
UK
Cross-sectional
n = 5,749 rail journeys
Data from British National Travel survey 1999–2001							(equivalent to 10–12 minutes per trip)
Morabia et al. (2010) [20]	Compare levels of physical activity between car & public transport commutes to work.	18 participants commuted by car to Queens College for 5 days than switched to commuting by public transport. (no public transport measure)	Activity diary +GPS system used to calculate the average metabolic equivalent value for car vs. public transport.		n/a as experiment limited to walking for transport.	no	Public transport commuters expended significantly more (+622 kcal over 5 days) energy compared with travelling the same route by car. (approximately equivalent to 30 minutes walking)
USA
Experimental
n = 18
Adults either working/studying at Queens College
Wener, R et al. (2007) [21] .	Compare level of physical activity between car and transit users travelling to/from work.	If travelled to work by:	Pedometer worn for 5 days and international physical activity questionnaire issued at start of measuring week.		no	(1) Income, gender & education.	(1) Train commuters walked significantly more steps (2,000 per day) compared to car commuters (equivalent to about 30 minutes).
USA
Cross-sectional
n = 177
Adults commuting from New Jersey to work in NY		public transport ≥ 4 × /week = transit user car ≥ 4 × /week = car user.				(2) Income, gender, education & commuting time.	(2) Train commuters 4 × more likely to achieve 10,000 steps/day compared to car users.
Davis, M et al. (2011) [22]	Describe the frequency, purpose & travel mode of daily trips in older adults & their association with participant characteristics & objectively measured physical activity.	Determined by respondent noting “mode of transport” in trip log.	Steps/day and minutes of moderate-intensity physical activity day assessed by accelerometer for 1week + daily trip log noting purpose of trip/mode of transport .		Did not adjust for “purpose of trip”.	(1) Other trip types (car, walking, cycling), age, sex, physical function, use of a walking aid, education & car ownership.	(1) Each weekly trip made by public transport is significantly associated with extra 412.7 steps/day in older adults (equivalent to about 8 minutes of walking).
UK
Cross-sectional
n = 214
Adults over 70 years old						(2) As per #1	(2) Public transport trips made by older adults is significantly associated with minutes of moderate-intensity physical activity/day (ln = 0.06).
Villanueva, K et al. (2008) [17]	Compare pedometer-determined physical activity levels of university students using public transport compared to cars for travel to uni.	Categorised into 2 groups: “mainly car user” or “mainly public transport user” for travel to uni.	Time spent walking for transport estimated from pedometer & diaries.		Adjusted for self-report leisure-time physical activity in analysis #2.	(1) Uncontrolled	(1) Public transport users took significantly greater steps (11,433 vs . 10,242) compared with drivers.(1,191 steps is equivalent to about 15 minutes of walking)
Australia (Perth)
Cross-sectional
n = 103
University students						(2) Gender, age and leisure-time physical activity.	(2) Public transport users significantly (3.55×) more likely to achieve 10,000 steps/ day compared with drivers.
Macdonald, J et al. (2010) [23]	Examine association between objective & perceived measures of the built environment, body mass index, obesity and meeting recommended physical activity (RPA) through walking and vigorous exercise. To assess effect of using light rail on weekly RPA.	Pre and post exposure to a new light rail transit line.	Categorised as either meeting the recommendations for physical activity through vigorous exercise or moderate-intensity physical activity (through walking) or not meeting recommendations.		no	(1) Age, gender, race, employment status, education, own residence, distance to work, perception of neighbourhood, access to parks, density of food/alcohol establishments, household density, use of public transport on weekly basis & propensity to use light rail.	(1) Light rail transit (LRT) users decreased their body mass index by average of 1.18 compared with similarly situated non-LRT users over 12–15 months follow-up.
USA
n = 498							(2) LRT users lived 1.5 miles from stations (equivalent to 36 minutes walking).
Cross-sectional and pre/post intervention						2) As per #1	(3) Association between LRT use and meeting weekly recommended physical activity levels by walking was in a positive direction but not significant.