The Carbon Footprint of Marathon Runners: Training and Racing

thon running leaves a signi cant carbon footprint regarding CO 2emissions; for example, 37 percent of New York Marathon participants travel internationally to New York. The aim of this study is to estimate the CO 2footprint of a person training and competing in a marathon; we will also propose methods to minimize the CO 2footprint because of transportation. In addition, we also examine the in uence of food practices and hygiene on training and racing a marathon. Methods: We estimated the annual carbon footprint of one person taking part in a marathon. We considered all training, racing, and travelling (local and international) for one person (we are going to give him the rst name of “Henri”), and then compared his CO 2footprint with his colleagues playing tennis and soccer. The excess CO 2footprint whilst running and for shoes, clothing, books, magazines, insurance, travel, hygiene, laundry, and resources for electronics and additional food consumed were calculated. For competitions, we estimated and compared the CO 2emission

person (we are going to give him the rst name of “Henri”), and then compared his CO 2footprint with his colleagues playing tennis and soccer. The excess CO 2footprint whilst running and for shoes, clothing, books, magazines, insurance, travel, hygiene, laundry, and resources for electronics and additional food consumed were calculated. For competitions, we estimated and compared the CO 2emission from transportation to national vs. international marathon (New York). Results: We estimated that our runner emitted 4.3 tons of CO 2equivalent (CO 2e), including all greenhouse gases. A transatlantic ight to New York corresponded to 3.5 tons CO 2, which is 83% of the annual carbon footprint of an average French citizen which is about 11 tons CO 2e/year. This leads to a sudden 40% increase in Henri's annual carbon footprint. Conclusions: By focusing on the additional carbon footprint from one year of marathon training and racing, and traveling locally versus internationally, this sport still has a potentially signi cant carbon footprint that runners and race organizers ought to consider. We wanted to answer a growing question of marathon runners who are wondering about the carbon footprint of their sports practice in following with a new environmentalist trend that considers not traveling anymore to participate in marathons and to stay local. However, the representativeness in the selection of calculation objectives is very low. There is no need for statistics since this study is a theoretical simulation of traditional training and competition practices of marathon runners. Keywords:carbon emissions; carbon impact; carbon calculator; environmental impact of sport 1. Introduction A carbon footprint is composed of the “total set of greenhouse gas emissions (CO2e or carbon dioxide equivalent) caused directly and indirectly by an individual, organization, event or product” [1]. Despite the health bene ts of running, the people involved with sports often engage in practices that produce large amounts of CO2emission [2,3]. The estimated quantity of CO2emissions from sports practices such as transportation, the construction of sports facilities, and the production of sporting goods and services [4] are a signi cant threat to the quality of the natural environment [5,6]. Modes of

bene ts of running, the people involved with sports often engage in practices that produce large amounts of CO2emission [2,3]. The estimated quantity of CO2emissions from sports practices such as transportation, the construction of sports facilities, and the production of sporting goods and services [4] are a signi cant threat to the quality of the natural environment [5,6]. Modes of transportation used by spectators and the athletes are believed to be the bulk of CO2emissions [7,8]. Int. J. Environ. Res. Public Health2021,18, 2769.

Int. J. Environ. Res. Public Health2021,18, 2769 2 of 10 The CO2emissions implications of training and competing in a marathon have not been studied. Previous studies have highlighted that sporting events have become a neg- ative contributor towards environmental degradation [2,9]. Indeed, the carbon footprint associated with sport participation has been a signi cant source of CO2emissions, (i.e., 8% of overall emissions for a German adult). Interestingly, non-mainstream individual sports such as diving, golf and sur ng leaves the three highest individual carbon footprints. The greenhouse gas emissions from more universal sports activities, such as cycling and walk- ing, are not negligible (because of additional fueling, walking, and cycling). Replacing short car trips with cycling or walking does not signi cantly produce a carbon emissions savings. Nowadays, sport is no longer considered to be separated from environment [10], and sports participation results in a disproportionate consumption of raw materials, traf c congestion, related air pollution, exhausting local water supplies, and a challenge around waste disposal [11,12]. However, increasingly there is a sociology of sports' awareness with the environment [13]. The notion of “environmental waves” of sport has been proposed to understand the past, present, and future of environmental sustainability [14,15]. There is a need for sports to nd a balance between the health bene ts and the associated CO2 emissions. Modi cations to equipment, infrastructure, materials, and industrial food are all current areas of interest [16,17]. Sustainable development of sports tourism as it relates to a positive carbon footprint is currently being investigated. In addition, the impact of new walking and cycling infrastructures (brides and paths) on CO2emissions from motorized only showed minor effects on CO2emissions; living near the infrastructures nor using it, predicted signi cant changes in CO2emissions [18]. Including active mobility sports such as cycling has been reported to be an additional source of CO2emissions due to fueling, walking and cycling. Human-powered locomotion is associated with non-negligible greenhouse gas emissions [19]. Marathons offer a unique opportunity to study the balance between sports partici- pation and CO2emissions. Marathon participation has exponentially increased over the last 2 decades and the

Including active mobility sports such as cycling has been reported to be an additional source of CO2emissions due to fueling, walking and cycling. Human-powered locomotion is associated with non-negligible greenhouse gas emissions [19]. Marathons offer a unique opportunity to study the balance between sports partici- pation and CO2emissions. Marathon participation has exponentially increased over the last 2 decades and the CO2emission associated with marathon events has exploded. The additional CO2emissions associated with training and competing in a marathon should be potentially given that runners often train locally, consume less industrial nutrition, and use domestic transportation. Our aim of this study is to test the hypothesis of a person who is training and com- peting in marathons locally (within 1000 km) and the associated CO2emissions related to this athletes' activities and preparation for his marathon. We also compared the CO2 emissions of the athlete competing in a marathon locally versus travelling internationally to New York. 2. Materials and Methods A carbon footprint is the total greenhouse gas (GHG) emissions or assessment caused by an individual, event, organization, service, or product which can be limited to its life cycle or one year. GHG are expressed as carbon dioxide equivalent (CO2e). The goal of the study is to focus on the primary sources of total CO2emissions and how to reduce future impact by direct or indirect modi cations. Several categories must be taken into consideration to evaluate GHG as it related to sports activity, such as raw energy consumption, raw materials and goods, food, services, transportation, travel, waste management, and equipment. To calculate the impact of the total emissions in equivalent CO2mass, the data are multiplied by emission factors. Our calculations are in line with IPCC (Intergovernmental Panel on Climate Change) works and publications which provide regular assessments of the scienti c basis of climate change, its impacts and future risks, and options for reducing GHG emissions on many levels. The aim of this study is to determine the carbon footprint of a typical French marathon runner preparing for a local marathon over a one-year period. We evaluated the results and costs associated

publications which provide regular assessments of the scienti c basis of climate change, its impacts and future risks, and options for reducing GHG emissions on many levels. The aim of this study is to determine the carbon footprint of a typical French marathon runner preparing for a local marathon over a one-year period. We evaluated the results and costs associated with the decision to compete locally versus internationally and assumed that our runner will live domestically and commute via conventional French transit systems.

Int. J. Environ. Res. Public Health2021,18, 2769 3 of 10 We then compared the results of our French marathon runner to his running colleagues as well to the other choices related to competing in a marathon. Finally, we will determine whether these observed activities are in line with reducing GHG emissions as it relates to the medium-term stabilization of climate change. 2.1. Marathon Runner Carbon Footprint Our French marathon runner, Henri, lives in Alfortville, which is a Paris-suburb about 7 km east of Paris-Notre Dame, France. On January 1st, Henri decides to run a marathon by the end of the year, and he chooses the New York City Marathon. In preparation, Henri runs nearly every day, competes in several local races, including the Paris Marathon in April. His programs consider all purchases, nutrition changes as it relates to his marathon preparation, which are grouped into fteen categories: Shoes: 4 pairs of running shoes Clothes: tee shirts (5), running shorts (3), running socks (10), water-proof track suit Miscellaneous running supplies: Camel-Back ® hydration system, head lamp (Nao-Petzl France ® ), Garmin ® GPS-watch, 1 running book (The Science of the Marathon©), running magazine subscriptions (Wider outdoor ® and Runners World ® ) Daily runs: running 20 km to work (La Defense) each morning (instead of using the subway station) Weekend runs: 15 km near his home Sports infrastructure: negligible because he runs existing on roads or tracks and we assume that he does not damage them Nutrition: besides his regular diet, he adds quinoa pasta (100 g), 4 eggs, meats (150 g), nuts (100 g), and prunes (250 g) Hygiene: 5 additional hot showers per week Laundry: 2 additional loads of laundry each month IT: 2 h of additional internet, computer, and smartphone use Running Race fees: running license, entry fees to three 10 km races, 3 half-marathons, 1 trail race, and the Paris Marathon (all races are local). He travels to these events by car or via public transportation. New York Marathon: race fees, lodging, food, economy class round trip airfare to New York (we assume a 50% chance his

and smartphone use Running Race fees: running license, entry fees to three 10 km races, 3 half-marathons, 1 trail race, and the Paris Marathon (all races are local). He travels to these events by car or via public transportation. New York Marathon: race fees, lodging, food, economy class round trip airfare to New York (we assume a 50% chance his wife will accompany him; thus we include half of the impact of a second airline ticket). Its CO2respiration additional emission is neglected because it corresponds to crop absorption on elds, as a carbon cycle effect–would omit this because the CO2emissions of produce transportation is not negligible and very dif cult to account for. The assessment will be presented with the six standard carbon footprint categories (Pandey et al., 2010): Energy: heat energy and electricity consumption. “Intrants”: goods, foods, and services purchases. Transportation: goods transportation. Travel: people traveling by mechanized systems. Waste: waste management. Immobilization: infrastructure amortization. 2.2. Changing the Carbon Footprint We change Henri's race location from the New York City Marathon to a closer city (1000 km round-trip) to estimate the decrease in the carbon footprint. 2.3. Other Leisure Sportive Activities Comparison Finally, we will compare the activity of marathon running to tennis and soccer, but in different ways.

Int. J. Environ. Res. Public Health2021,18, 2769 4 of 10 Choosing tennis as an alternative activity (at a similar level) would correspond to the purchases of different goods (racket, tennis clothes, balls, and stringing), tennis club membership, weekly practice, tournament fees, and tickets and travel to the “Roland Garros Open de France” tennis tournament. Regarding soccer, we assume that the person is a fan and not a player. The soccer fan supports a professional team which competes at national and international level. This activity will comprise purchasing one stadium season pass (in the Parc des Princes, supporting Paris-Saint-Germain soccer team), a subscription to a dedicated sports channel, purchasing a new wide-screen television set (assuming his current television is not broken), purchasing additional clothes (team scarf, team shirt with the name of his preferred player), eating additional foods while watching matches (peanuts, beers, and champagne), traveling occasionally to follow his team through France (by train or car-sharing), traveling by plane to see two European championship matches, and using more internet. We also replaced the professional events by a national tennis match and to a local fan zone attendance. 3. Results The carbon footprint according each sport and traveling conditions is expressed in absolute tCO2e and relative value to the annual French carbon footprint is indicated in Table. 3.1. With the New York City Marathon Option The rst evaluation of GHG representative emissions shows a total mass of 4.3 tons of CO2e (equivalent CO2including the effect of all GHG emitted), as represented in Figure.Int. J. Environ. Res. Public Health 2021, 18, 2769 5 of 10 Figure 1. The carbon footprint of the marathon runner during 1 year of training and racing, including an international marathon in New York City. In this case, it shows the greatest impact in the travel category, with the New York trip representing nearly all (83%) of the whole carbon footprint (3.56/4.3). If we compare this global impact to the French annual carbon footprint of 11 tCO 2e, we note that this running activity represents, on average, an additional 40% GHG impact. This is mainly due to the

it shows the greatest impact in the travel category, with the New York trip representing nearly all (83%) of the whole carbon footprint (3.56/4.3). If we compare this global impact to the French annual carbon footprint of 11 tCO 2e, we note that this running activity represents, on average, an additional 40% GHG impact. This is mainly due to the transatlantic travel for the New York City Marathon. 3.2. With the Local Marathon Option By replacing the New York trip with a closer destination corresponding to a train travel (we supposed a 1000 km round trip), the total mass is lowered 6 times less to 0.7 tCO 2e, (Figure 2). Interestingly, the travels impacts are almost neutral: running daily to work instead of using public transportation almost compensates for the additional travel to go to races. Figure 2. The carbon footprint of the marathon runner for one year of training and racing replacing the transatlantic mar- athon by a closer destination corresponding to a train travel (assuming a 1000 km round trip). Figure 2 demonstrates that the first item is now the “intrants” category, which is mainly composed of electronics, race fees, and additional food. The second item is energy, mainly composed of additional showers. Figure 1. The carbon footprint of the marathon runner during 1 year of training and racing, including an international marathon in New York City. In this case, it shows the greatest impact in the travel category, with the New York trip representing nearly all (83%) of the whole carbon footprint (3.56/4.3). If we compare this global impact to the French annual carbon footprint of 11 tCO2e, we note that this running activity represents, on average, an additional 40% GHG impact. This is mainly due to the transatlantic travel for the New York City Marathon. 3.2. With the Local Marathon Option By replacing the New York trip with a closer destination corresponding to a train travel (we supposed a 1000 km round trip), the total mass is lowered 6 times less to 0.7 tCO2e, (Figure). Interestingly, the travels impacts are almost neutral: running daily to work

the transatlantic travel for the New York City Marathon. 3.2. With the Local Marathon Option By replacing the New York trip with a closer destination corresponding to a train travel (we supposed a 1000 km round trip), the total mass is lowered 6 times less to 0.7 tCO2e, (Figure). Interestingly, the travels impacts are almost neutral: running daily to work instead of using public transportation almost compensates for the additional travel to go to races.

Int. J. Environ. Res. Public Health2021,18, 2769 5 of 10 Table 1.Synthesis of the carbon footprint according to the sport and travel conditions. In absolute value (tCO 2e/year) and relative to the French carbon footprint. tCO2e/year Sports Energy (tCO2/year % of the Total Activity) Intrants Transportation Travels Waste Immobilization Carbon FootPrint Total % of Current French Carbon Footprint marathon without transatlantic ight 0.24 33% 0.43 59% 0.01 2% 0.01 1% 0.03 4% 0.01 1% 0.73 7% marathon with transatlantic ight 0.24 6% 0.43 10% 0.01 <1% 3.56 83% 0.03 1% 0.01 <1% 4.28 39% Tennis 0.19 31% 0.08 13% 0.01 2% 0.30 49% 0.01 2% 0.02 3% 0.61 6% Fan-club Soccer 0.08 4% 0.62 28% 0.01 <1% 1.44 65% 0.01 <1% 0.06 3% 2.22 20% tCO 2e/year

This study estimates the CO2 footprint of marathon training and racing, proposing methods to minimize it.