Quantifying the physical activity energy expenditure of commuters using a combination of global positioning system and combined heart rate and movement sensors.

BACKGROUND: Active commuting may help to increase adults' physical activity levels. However, estimates of its energy cost are derived from a small number of studies which are laboratory-based or use self-reported measures. METHODS: Adults working in Cambridge (UK) recruited through a predominantly workplace-based strategy wore combined heart rate and movement sensors and global positioning system (GPS) devices for one week, and completed synchronous day-by-day travel diaries in 2010 and 2011. Commuting journeys were delineated using GPS data, and metabolic intensity (standard metabolic equivalents; MET) was derived and compared between journey types using mixed-effects linear regression. RESULTS: 182 commuting journeys were included in the analysis. Median intensity was 1.28 MET for car journeys; 1.67 MET for bus journeys; 4.61 MET for walking journeys; 6.44 MET for cycling journeys; 1.78 MET for journeys made by car in combination with walking; and 2.21 MET for journeys made by car in combination with cycling. The value for journeys made solely by car was significantly lower than those for all other journey types (p<0.04). On average, 20% of the duration of journeys incorporating any active travel (equating to 8 min) was spent in moderate-to-vigorous physical activity (MVPA). CONCLUSIONS: We have demonstrated how GPS and activity data from a free-living sample can be used simultaneously to provide objective estimates of commuting energy expenditure. On average, incorporating walking or cycling into longer journeys provided over half the weekly recommended activity levels from the commute alone. This may be an efficient way of achieving physical activity guidelines and improving population health.JP is supported by an NIHR post-doctoral fellowship [2012-05-157] and SC, DO and SB are supported by the Medical Research Council [Unit Programme numbers MC_UU12015/6 and MC_UU_12015/3]. The Commuting and Health in Cambridge study was developed by David Ogilvie, Simon Griffin, Andy Jones and Roger Mackett and initially funded under the auspices of the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence. Funding from the British Heart Foundation, Economic and Social Research Council, Medical Research Council, National Institute for Health Research and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. The study is now funded by the National Institute for Health Research Public Health Research programme (project number 09/3001/06).This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.ypmed.2015.09.02

The spatiotemporal characteristics of 0–24-goal polo

Polo is an equestrian sport that requires two teams of four players to score goals at opposing ends of a 150 m × 275 m pitch. Each player is rated on a handicap system (−2 to +10) that quantifies their abilities and permits their inclusion in different levels of Polo play; the cumulative handicap of the four players sets the level of play. Using GPS technology, we investigated how levels of Polo differ regarding distance covered, speeds achieved and high-intensity activities performed. As cumulative Polo handicap increased, so too did the distances and average speeds attained, decelerations performed and impacts encountered during each period of play. These findings suggest that as each player improves and increases their handicap, they will need to ensure the ponies they play have sufficient aerobic, anaerobic and speed capacities to perform effectively at that level. This information provides valuable insights to Polo players, grooms and equine vets, as to how they can best prepare their ponies for game-day and how they may be able to maintain pony longevity in the sport

The spatiotemporal characteristics of 0 – 24 goal polo

Global positioning systems (GPS) have recently been shown to reliably quantify the spatiotemporal characteristics of Polo, with the physiological demands of Polo play at low and high goal levels also investigated. This study aimed to describe the spatiotemporal demands of Polo across 0 – 24 goal levels. A player worn GPS unit was used to quantify distance, speed and high intensity activities performed. Data was divided into chukkas and five equine-based speed zones, grouped per cumulative player handicap and assessed using standardised mean differences. Average distance and speed per chukka increased in accordance with cumulative player handicap, with the magnitude of differences being Trivial – Large and Trivial – Very Large, respectively. Differences between time spent in speed zones 4 and 5 show a linear increase in magnitude, when comparing 0 goal Polo to all other levels of play (Small – Very Large; 6 – 24 goals, respectively). High intensity activities predominantly shared this trend, displaying Trivial – Large differences between levels. These findings highlight the increasingly demanding cardiovascular, anaerobic and speed-based needs of Polo ponies as playing level increases. Strategies such as high intensity interval training, maximal speed work and aerobic conditioning may be warranted to facilitate this development and improve pony welfare and performance

Local Positioning Systems in (Game) Sports

Position data of players and athletes are widely used in sports performance analysis for measuring the amounts of physical activities as well as for tactical assessments in game sports. However, positioning sensing systems are applied in sports as tools to gain objective information of sports behavior rather than as components of intelligent spaces (IS). The paper outlines the idea of IS for the sports context with special focus to game sports and how intelligent sports feedback systems can benefit from IS. Henceforth, the most common location sensing techniques used in sports and their practical application are reviewed, as location is among the most important enabling techniques for IS. Furthermore, the article exemplifies the idea of IS in sports on two applications

Estimating Personal Physical Activity from Transport

A substantial and growing proportion of people in developed countries are overweight or obese. Personal physical activity protects against weight gain and obesity. Personal physical inactivity has been linked to a number of common and increasing prevalent health problems such as cardiovascular disease and a number of chronic diseases such as cancer (colon and breast), diabetes mellitus, osteoporosis and depression. Accelerometers can be used to objectively measure a person‟s incidental, intermittent physical activity such as short walks. They also enable movement to be monitored inside buildings that is often not recorded and is difficult using other technologies such as Global Position Systems (GPS). Accelerometers allow comprehensive analysis of physical activity bouts. They also have low subject burden, not having to rely on the memory of individuals and are unobtrusive, and allow recording over multiple days. However, accelerometers do not accurately record physical activity associated with cycling. GPS can be used to estimate personal energy expenditure from cycling since the speed and duration of movement is logged. However, GPS does not provide data at some locations such as inside buildings, urban canyons, or tunnels due to weak signals from satellites. Transport is a major activity type and common form of personal physical activity. This paper describes procedures for integrating GPS and accelerometers to estimate personal physical activity arising from transport. It provides experimental evidence using data from one subject and suggests that this method has potential for further investigation

Analysis of road sprint cycling performance

Sprint cycling ability is a key determinant of road cycling performance, with many races designed specifically for sprinters. The ability to excel in the final sprint is relevant for both individual riders and teams. Despite the importance of sprints within professional road cycling, the characteristics of professional road sprints and sprinters have yet to be extensively described. Thus, the overall objective of the five research studies contained within this doctoral thesis was to describe road cycling sprint performance and improve the general understanding of the physical, technical and tactical factors associated with such performances. The first two descriptive field studies document the physical and physiological demand of sprint races during actual road cycling competitions. Specifically, Study 1 was designed to quantify the demands of sprinting in the male professional category. Seventeen competitions from six male professional cyclists (mean ± SD: age, 27.0 ± 3.8 y; height, 1.76 ± 0.03 m; weight, 71.7 ± 1.1 kg) who placed Top 5 in professional road races were analysed. Calibrated SRM power meters were used to monitor power output, cadence and heart rate. Data were averaged over the entire race, different durations prior to the sprint (60, 10, 5 and 1 min) and during the actual sprint. Variations in power during the final 10 min of the race were quantified using Exposure Variation Analysis. Power, cadence and heart rate were different between various phases of the race, increasing from 316 ± 43 W, 95 ± 4 rpm and 88 ± 3 % of maximal heart rate in the last 10 min to 487 ± 58 W, 102 ± 6 rpm and 96 ± 2 % of maximal heart rate in the last minute prior to the sprint. The peak power during the sprint was 17.4 ± 1.7 W∙kg-1. Exposure Variation Analysis revealed a significantly greater number of short duration and high intensity efforts in the final five minutes of the race, compared with the penultimate five minutes (p=0.01). These findings quantified the power output requirements associated with high level sprinting in men’s professional road cycling and highlighted the need for both aerobic and anaerobic fitness. In Study 2, the characteristics of successful road sprints in professional and under 23 y male cycling races were compared. As in Study 1, Study 2 also described the exercise intensity for the sprinters throughout final 10 min of the race. Nine successful (Top 3) sprints performed by a professional (PRO: 23 y, 1.76 m, 71.8 kg) and an under 23 (U23: 18 y, 1.67 m, 63.2 kg) cyclist sprinter were analysed in this study. No statisticaldifferences were found between PRO and U23 in the absolute peak power, mean power, duration and total work during the sprint (PRO: 1370 ± 51 W, 1120 ± 33 W, 14.5 ± 2.4 s, 16.2 ± 2.6 KJ; U23: 1318 ± 60 W, 1112 ± 68 W, 12.8 ± 1.1 s, 14.2 ± 1.4 KJ). However, the intensity of the race recorded in the last 10 min prior to the sprint was significantly higher in PRO compared with U23 (4.6 ± 0.3 and 3.7 ± 0.2 W·kg-1, respectively). Race duration, total elevation gain (TEG) and mean power were similar between PRO and U23. In conclusion, the physiological demands leading into road sprints (intensity of the last 10 min) were found to be higher in PRO compared to U23 races. Nevertheless, a similar sprint power output (\u3e 2500 W·Ap-1 or \u3e 15.5 W·kg-1 for approximately 14 s, with a peak power output \u3e 3100 W·Ap-1 or \u3e 19 W·kg-1; where Ap is Projected Frontal Area) indicates that sprint characteristics may be similar in PRO and U23. As a result of the findings observed in the first two studies of this thesis, Study 3 was designed to better understand the effects of variable and non-variable exercises that replicate the intensity of the final portion of road competitions on maximal sprint performance. In this laboratory trial, ten internationally competitive male cyclists (age, 20.1 ± 1.3 y; height, 1.81 ± 0.07 m weight, 69.5 ± 4.9 kg; and VO2max, 72.5 ± 4.4 ml·kg-1·min-1) performed a 12-s maximal sprint in a rested state and again following: i) 10 min of non-variable cycling, and ii) 10 min of variable cycling. Variable and non-variable trials were conducted in a randomized, crossover fashion. The intensity during the 10 min efforts gradually increased to replicate the pacing observed in final sections of cycling road races. During the variable cycling subjects performed short (2 s) accelerations at 80% of their peak sprint power, every 30 s. Mean power output, cadence and heart rate during the 10 min efforts were similar between conditions (5.3 ± 0.2 W∙kg-1, 102 ± 1 rpm, and 93 ± 3 %, respectively). Post exercise blood lactate concentration and perceived exertion immediately after exercise were also similar (8.3 ± 1.6 mmol∙L-1, 15.4 ± 1.3 (6-20 scale), respectively). Peak and mean power output and cadence during the subsequent maximal sprint were not significantly different between the three experimental conditions (p≥0.14). These results indicate that neither the variable nor the non-variable 10 min efforts performed within this study impaired the sprint performance in elite competitive cyclists. Due to the importance of the elevation gain variable in road cycling, the fourth study of this thesis was methodological and investigated the consistency of commercially available devices used to measure the TEG during races and training. This chapter was separated in two observational validation studies. Garmin (Forerunner 310XT, Edge 500 Edge 750 and Edge 800; with and without elevation correction) and SRM (Power Control 7) devices were used to measure TEG over a 15.7 km mountain climb performed on 6 separate occasions (6 devices; Study 4a) and during a 138 km cycling event (164 devices; Study 4b). TEG was significantly different between Garmin and SRM devices (p The final study of this thesis was an analysis of technical and tactical factors that influence sprint performance in professional competitions; particular focus was put on the TEG which was a factor identified as a potential cause of fatigue. More specifically, the subject of Study 5 was the highest international ranked professional male road sprint cyclist during the 2008-2011 seasons. Grand Tour sprint stages were classified as WON, LOST, or DROPPED from the front bunch prior to the sprint. Video of 31 stages were analysed for mean speed of the last km, sprint duration, position in the bunch and number of teammates at 60, 30, and 15 s remaining. Race distance, TEG and mean speed of 45 stages were determined. Head-to-head performances against the 2nd to 5th most successful professional sprint cyclists were also reviewed. Within the 52 Grand Tour sprint stages the subject started, he WON 30 (58%), LOST 15 (29%), was DROPPED in 6 (12%) and had one crash. Position in the bunch was closer to the front and the number of team members was significantly higher in WON compared to LOST at 60, 30 and 15 s remaining (p In conclusion, the general findings of this thesis were as follows: as expected, exercise intensity significantly increases in the last 10 min of relatively flat road races; there is a significantly greater number of short duration and high intensity efforts in the final 5 min of competitive road cycling races when compared with the penultimate 5 min; sprint duration and peak power output does not differ between PRO and U23 races and is approximately 13 s and 17 W∙kg-1, respectively; the physiological demands in the 10 min before the sprint are higher in PRO compared to U23 races; neither a variable nor a non-variable 10 min lead up effort appears to impair the sprint performance of elite competitive cyclists; measurements of elevation gain are consistent within devices of the same brand, but differed between brands or when different settings were used; and technical and tactical aspects of road sprinting are related to performance outcomes