Running with a bag: encumbrance, materiality and rhythm

ABSTRACT Advancing social and cultural geography’s interest in sport, exercise and commuting, as well as the everyday experiences of movement, materiality, and rhythm, this paper provides the first account of run-commuting experiences through a focus on running with a bag. Run-commuting is an emerging active travel practice in which people run to and/or from work. It blurs the usual separation of mobilities related to work and those related to sport, exercise and leisure. In doing so, new body-objects assemblages are introduced into running and commuting practices that have marked impacts on the experiences of mobility. Drawing on interviews and run-alongs with 19 UK run-commuters, this paper explores one such defining experience – running with a bag. Drawing together the concepts of affective materialities and rhythm with work on mobilities and sport, this paper discusses how experiences of running with a bag are marked by disruptive rhythms, managing rhythms and acclimatising to such rhythms. As such, this paper demonstrates the centrality of objects in facilitating and constraining practices, as well shaping the experiences of mobility and exercise. The novel engagement with material and bodily rhythms in this paper also offers fruitful avenues for future mobile, sporting, material and rhythmic thinking in geography.


Introduction
'I have run with a rucksack before. I don't particularly like it and I'd rather not basically . . . It's not comfortable. Everything's like banging about.' (Harriet) 'I tried it once before and it was just a massive pain in the arse. I don't like the idea of being restricted, and the one that I had, I didn't find it was that comfortable . . . It just feels like quite constricted and things would move around and jangle around and stuff. Like, even when my keys jangle it drives me insane. Having loads of stuff in my bag would be like, ugh . . . I feel like maybe if I ran with a bag on, I'd be a bit like, "That's work on my back." Because it'd have my work clothes in or it'd have something to do with work, so I'd be like, "Oh my god, I can't escape. It's literally on my back".' (Holly) Bags are controversial objects within running practices that can spark impassioned responses from runners for the embodied and symbolic transformations of running they can trigger. Harriet and Holly are both run-commuters -people who run to and/or from work in multi-or mono-modal journeys (Cook, 2021). For many run-commuters, bags are essential to facilitating the practice by enabling required objects to move with them between home and work but also form new body-object configurations that have significant effects. For Harriet and Holly, the addition of a bag results negatively in physical, psychological and rhythmical encumbrance; it constricts, imprints, jangles and bangs, producing uncomfortable and undesired experiences that can curtail and inhibit. This begs the questions of how bags are incorporated into run-commuting, how they are experienced and with what impacts.
These questions lie at the heart of this paper and answering them contributes to social and cultural geography's concern with the material (Owen & Boyer, 2019;Walker, 2020), everyday mobile commuting experiences (Lee, 2016;Ravensbergen, 2020), and their entanglements (Bissell, 2009;Simpson, 2019;Watts, 2008). This work is also situated within the recent revitalisation of geographical interest in sport, exercise and fitness practices. This work, broadly, explores where and how such activities happen, the barriers and facilitators of these practices, how they are represented and experienced, as well the socio-political-cultural implications they have for individuals, societies, and spaces. This work marks a change in sport geography's focus from Bale's (2003) seminal characterisation of the field to a concern with the popular and everyday, as opposed to the elite. Andrews (2017) refers to this as a switch from post-game to play-by-play, a move that has worked to animate the movement-spaces of geographical research into sport. Alongside other reviews and agendas (Koch, 2018;Latham & Layton, 2020;Wise & Kohe, 2020), Hitchings and Latham (2017) well-encapsulate these renewed geographical interests, arguing for further attention to materials, sociality, physical pleasures, and the evolution of sport, exercise and fitness practices. This study draws influence from such work (particularly those related to running) and helps advance such themes by using rhythm to explore the material-mobility relations and (dis)pleasurable experiences of running with a bag, and how individuals evolve their practices to manage these in ways that sustain and enable run-commuting.

Run-commuting and the matter of bags
By no means a new practice, run-commuting is one that has been rapidly growing in popularity around the world in recent years but particularly in the UK where suggestive Strava data indicates a doubling of run-commuters between 2016 and 2018 (Cook, 2021), and there are calls for running to be taken seriously as an active travel mode within transport policy and practice (Alger, 2020). These increases are significant. As an alternative active commuting mode, rising run-commuting rates can contribute to combined public and environmental health goals of reducing physical inactivity, carbon and noise pollution, and improving air quality and place vibrancy that are associated with greater active travel use. However, rather than being motivated by such societal benefits, the growth of run-commuting in the UK has largely been fuelled increasing cognisance of the practice as a pragmatic, temporally-efficient solution to the difficulties of maintaining running habits in an accelerated society (Cook, 2020a(Cook, , 2021. By repurposing the incumbent moments of a commute, run-commuting blurs the traditional time-space separation of mobilities related to work and those related to sport/exercise/leisure (this is not unique to running -see, Larsen, 2018). Such blurring introduces new subjectivities, materials and movement into the spaces of both commuting and running. Running with a bag is a prime example of such new body-object configurations.
A bag is not a usual running object and the potential need to wear one marks this as a distinguishing feature of run-commuting. Run-commuting's function as a mode of transport can necessitate that stuff moves as well as people. Given the limited carrying capacities of runners in motion, a bag, and by extension the body, is often the solution to these cargo needs. Bags are crucial in the logistics of run-commuting. They speak to the multi-modal and multi-purpose assemblages of run-commuters who are not only moving as runners, but also as employees and public transport users, replete with the stuff needed for each and to transition between them (Cook, 2020a). In these ways, bags have become a defining trait of run-commuting -crucial to the logistics and facilitation of the practice but resulting in more heavily encumbered running bodies that radically affects the experience of running.
Bodies are intensely enrolled into the performance and understanding of running (Allen-Collinson, 2005;Cook et al., 2016;Hockey, 2013;Lev, 2019;Lorimer, 2012). This has been referred to as the excessiveness of exercise (Barnfield, 2016a) and the intense embodiment of running (Allen-Collinson & Owton, 2015;Larsen, 2019), expressing how the heightened animation of the running body is affected and becomes affective across numerous registers. This intensity results in a delicate equilibrium: a balance between embodied stimuli and the body's capacities to manage these positively (Bissell et al., 2017). This equilibrium can easily be disrupted in running should the two sides of this equation become unbalanced. Should the qualities or quantities of the stimuli changesuch as weather (Allen-Collinson et al., 2019), surfaces (Barnfield, 2020), or encounters (Cook et al., 2016) for example, -or the bodily skills of runners decrease -through fatigue, rustiness or injury (Lev, 2021) -then a tipping point (Bissell, 2014a) can be reached where the embodied experiences of running transitions, potentially to one of displeasure. This is the risk of running with a bag and its importance should not be trivialised. The prospect of wearing a bag is a major barrier for many to run-commute (either entirely or at desired frequencies) and leads to often complex and laborious logistics routines to reduce the need to run with one (Cook, 2020a(Cook, , 2021. Better understanding the experiences of running with a bag can provide insights into how bag-use in run-commuting can be made more pleasurable and manageable to decrease such barriers. Thus, contributing to understandings of how sport, exercise and commuting practices are accomplished and how they can be done more widely to the benefit of society, individuals and places.
To explore this further, I draw on geographical literature concerning affective materiality and rhythm, particularly in relation to sport and mobile practices. Following this, I detail the methods and materials informing this paper, before exploring experiences of running with a bag. These are structured around two main themes: disruptive rhythms, which explores the embodiment of running with a bag, and managing rhythms, which explores tactics employed to tame such disruptiveness. These findings contribute to the increasing geographical interest in sport and commuting practices by illuminating the embodied experiences of run-commuting and the centrality of bags to this emerging mobile practice. They also advance work on affective materiality in social and cultural geography by connecting it to notions of rhythm and progresses endeavours to embody and energise rhythmanalysis.

Encumbrance and materiality
Running with a bag is a matter of encumbrance. This speaks to the lived experience of materials, recognising that objects have their own qualities that stimulate and affect, that bodies relate to, and become an integral element of experience. Mobility encumbrances and their social implications have been discussed in many forms, from women carrying others in reproductive mobilities (Sheller, 2020), horses carrying troops and trade (Virilio, 2006) and the hindrances of pram mobilities (Boyer & Spinney, 2016), to the exclusion of laden bodies at transit turnstiles (Muñoz, 2020), the burdens of disabled mobility discourses (Imrie, 2000) and the piggybacking encumbrances of viral mobilities (Lavau, 2014). In this paper, I consider the encumbrance of running with a bag by bringing together two conceptual tropes -affective materiality and rhythm. This section seeks to outline how social and cultural geographical work into mobility has understood these ideas, how they apply to the practice of running, and where run-commuting may challenge or alter some of these experiences.
The affectivity of objects and stuff has been an important avenue of research into mobilities, partly inspired by relational approaches in geography and the complex interrelatedness of things and people apparent in assemblage and affect theories, among others (Jensen et al., 2020). This work shows that objects have the agency to mediate and transform embodied experiences of movement and Bissell's (2009) work on everyday encumbrance in railway stations demonstrates this well. Bissell shows that the mobile objects people move with facilitate and encumber movements by extending bodies and impressing limitations; suitcases in train travel enable passengers to move with more things whilst simultaneously making that movement more challenging. He employs the term mobile prosthetics to encapsulate this extending of the body by mobile objects, which alter the capacities of the body and affective experiences had. Literature in disability studies also discusses the simultaneous 'wounding and enabling' (Jain, 1999, p. 31) effects of prostheses, such as wheelchairs that may afford mobility whilst being uncomfortable and dangerous (Bonehill et al., 2020).
As Barnfield (2016b) argues, the objects of running are inseparable from runners and are agents in the production of the practice. Shoes, clothing, headphones and wearable devices are some of the mobile prostheses within running assemblages that affect movements and experiences (see, Latham & Layton, 2020). Within run-commuting, the bag is most prominent and remarkable, signifying the practice's position between the spheres of transport and sport/leisure mobilities. Yet it is something of an unknown quantity in running practices and, indeed, rarely features in discussions of mobility either.
Studies about bag use and their material cultures tend to revolve around iconicity, performance and their importance as identity and memory objects (Buse & Twigg, 2014;Rosenberg et al., 2020) rather than what it is like to move with them. Yet, as Walsh and Tucker (2009, p. 225) remark in relation to backpacking performances: 'the backpack is not only semiotically fused to the backpacker's identity, but also physically fused to the backpacker's body . . . this type of luggage is pivotal in backpacker's bodily performance. From this embodied perspective . . . the backpack determines corporeal ways of knowing'. This construction of alternative embodied forms of knowledge is common with other prostheses too, such as the use of white canes by visually impaired people (Šakaja, 2020). Thus far, however, only a couple of studies have researched the impact of bag-use on running, applying a sport science perspective (Scheer et al., 2019(Scheer et al., , 2020 to investigate the economy and energy costs of running with a bag. As such, lived experiences of running with this particular mobile prosthesis remains unexplored, which this paper seeks to rectify.

Rhythm
While the impact of materials on mobility have been explored variously, the lens of rhythm is rarely employed to understand the affectivity of stuff on mobile experiences. Yet, returning to the quotes that opened this paper, a striking rhythmicity or maybe arrhythmia comes through clearly. The issues Harriet and Holly take with the affectivity of a bag concern constriction, banging and jangling, all terms with rhythmic, auditory and vibratory associations. This suggests the affectivity of running with a bag is most readily perceived by runners' rhythmic registers, and something worthy of further exploration. The recent spate of research analysing running through the concept of rhythm is testament to the centrality of rhythm to running practices and its conceptual value for understanding running experiences Edensor & Larsen, 2018;Larsen, 2019).
Rhythm is a temporal dimension concerning starts, stops, cycles, tempos, repetitions, patterns and differences. Rhythmanalysis, as set forth by Lefebvre (2004), is an approach to understanding everyday life through a receptivity to such dimensions and how they affect and structure. It is both an analysis of rhythms -bodily, social, elemental, daily, economic, cultural, political etc -and analysis through rhythms, utilising rhythms to shed light of spaces, places, bodies and life. It has predominantly been used to understand place rhythms, how places are reproduced and reconstituted by the rhythms that flow through them, and how bodies sense, embody and respond to these rhythms (Edensor, 2010;Larsen, 2019;Mels, 2004). These perspectives have been applied fruitfully to the analysis of running mobilities in recent years, particularly in understanding how running events may disrupt usual place-rhythms and how running practices are forged and maintained within the rhythms of everyday life (Cidell, 2014;Edensor & Larsen, 2018).
Yet for understanding the intense embodiment of running with a bag, these placebased rhythms are less influential and of greater significance are corporeal rhythms. These have received less attention in rhythmanalysis (Larsen, 2019), which has generally considered how bodies engage with external rhythms rather than their own. Jonas Larsen's (2019) fleshy ethnography of the bodily and biological rhythms entangled in Etape Bornholm, a five day running event in Denmark, has recently begun to rectify this. He shows how running can be considered as a polyrhythmic ensemble in which runners' internal, corporeal, somatic, and biological rhythms are held central to the embodiment of that practice (Larsen, 2019).
Such understandings are not only found in academic analyses, however. Runners in this study readily recognised the concept of rhythm and rhythmic experiences as important to their practice too: 'I would say when you get into a rhythm, your effort level can just really come down and just swing your arms and your legs and listen to what you're listening to or think about whatever your head takes you, and then really you're just like, not really thinking about running here. Whereas if it stops and starts, you're always like, looking left, looking right, "Oh, I've stopped here now. Gotta accelerate again." It's much harder.' (Carl) Carl's construction of rhythm as an achievement or a particular state here is important for investigating running with a bag. Rather than seeing all running as rhythmical, participants in this study generally talked about finding their rhythm during a run. This implies there is an optimal rhythmic ensemble for each runner when the rhythms of legs swings, arm raises, breaths and heartbeats are all in harmony, resulting in positive experiences. This rhythmic alignment could be considered as running eurhythmia and the quest for this can be a constant one. Runners often describe a continual evaluation of their internal somatic rhythms. These rhythms are often apprehended and evaluated by listening to the body (Barnfield, 2016a;Samson et al., 2017) and a technological listening where selftracking technologies provide abstract data that runners entwine with their embodied experiences to evaluate their rhythmic ensemble (Esmonde, 2019). In the varied processes of finding their rhythm, and maybe losing it again, runners are experiencing arrhythmia and a body out of flow, when the experience is not so pleasant (Larsen, 2019). As such, eurhythmia could be considered as an embodied desire of run-commuters who want experiences marked by flow and rhythmic alignment (Csikszentmihalyi et al., 2017).
These rhythmic and material perspectives offer important ways of apprehending the experiences of running with a bag on the polyrhythmic ensemble of run-commuting. They draw attention to the tempos, cadences and synchronicities of body-object relations on the move, that provide valuable ways of understanding the experiences of mobility and sporting practices, and their significance.

Researching running with a bag
This paper emerged from a wider project studying the emergence, production and potential of run-commuting in the UK (Cook, 2020a). The empirical material presented in the paper stems from two methods within the project's methodological bricolage. Firstly, interviews (face-to-face or Skype) were conducted with 19 run-commuters based in five cities in the UK between December 2016 and July 2017 (see Supplementary Material). Although the sample is more diverse than the 'average' run-commuter (Cook, 2021), the run-commuters in this study are still predominantly urban-dwelling, well-paid, highly educated, middle-aged white runners in professional industries. They started run-commuting, mostly, due to increases in running demands (such as training for a marathon) or increased responsibilities in work or home life (notably having children) that made it difficult to fit running into their everyday lives. Therefore, it is important to recognise the situatedness of participants' experiences and how they might differ from others' experiences. In particular, they are not reflective of the experiences of differently-abled bodies, of those new to running or of those whose running may be deemed riskier or out of place (such as Black runners -Hornbuckle, 2021;Smith-Tran, 2021). Furthermore, running with a bag within the typically middle-class context of running for recreation, sport, and exercise in the UK (Caudwell, 2015) is likely to be distinct from other running cultures, such as the experiences of those for whom running with (or lugging) a bag is work and/or involuntary, for example, Sherpas. Thus, this paper is a partial insight into running with a bag, providing an in-depth exploration of the specific experience of run-commuters in the UK. The semi-structured interviews with participants were audiorecorded, transcribed and coded in order to analyse the materials and interpret pertinent themes in the empirical data. To aid the preservation of anonymity, participants has been given pseudonyms in this paper.
Secondly, seven of the interviewed run-commuters undertook an additional go-along interview. Go-along interviews were used in this project to interrogate in-the-moment experiences of run-commuting as they involve the researcher participating in the practice being studied and experiencing the places and spaces within which a practice may take place (Anderson, 2004). Interviewing participants about their thoughts, feelings, experiences and actions at the point at which they are taking place, such as when running with a bag, can result in rich insights into experiences (Finlay & Bowman, 2017) that this project sought to harness. Likewise, the joint accomplishment of a run together (Hockey & Allen-Collinson, 2013) was a valuable aspect of this research tool. 'Accomplishing something together', as I have commented elsewhere, 'undoubtedly helped to develop this rapport, especially as I was also an insider to the practice. Rather than feeling like a research interview, participants often commented that it just felt like talking to another runner as they normally would on a run' (Cook, 2020b, p. 202), which further encouraged open discussions. It also provided autoethnographic engagement with running with a bag, which has been further complemented in this paper by reflections on my own running and run-commuting practices.
Run-commuters took me on their usual routes and the dialogue was very loosely structured to allow topics to adapt to changing situations, and for questions to evolve from spontaneous encounters or experiences on the run (the practicalities of run-along interviews are discussed in Cook, 2020b). In doing so, run-commuters took me into their embodied run-commuting worlds (as partial and situated as they may be) which generated rich insights into running with a bag, which the following sections explore.

Disruptive rhythms
As noted, the intense embodiment of run-commuting and fragility of running rhythms entails that any additions to the running assemblage could have disproportionate and arrhythmic impacts. My own running rhythms now include a wonky right arm that swings elliptically rather than the usual forward and back, a legacy of my body's rhythms counteracting the weight of a water bottle I carried on longer runs. As such, the impact of stuff on a runner's body is not trivial and can impress themselves longer term.
Participants' general consensus on running with a bag is one of tolerability. No one actively enjoyed running with a bag but most were able to tolerate it for the facilitation it offered their run-commuting. This is not to say that run-commuters do not have their gripes about wearing a bag or are unaware of the bodily implications. These were regularly discussed as (potentially) disruptive to their running rhythms in a few key ways.
Most run-commuters found the experience of running with a bag at least slightly disruptive to their usual rhythms and experiences. This was due to the impacts on their extant running rhythms and the new rhythms introduced by the bag itself: 'Find it a bit restrictive . . . makes me feel a bit heavier . . . I quite like the kind of freedom of just running and not being constrained by anything.' (Fiona) 'I think for me it's just the restrictive nature of it . . . So the bag I've got, it's got shoulder straps, a chest strap and a waist strap, and occasionally, the waist strap, even when it's loose, it still catches me and it doesn't wind me, but I'm conscious of it . . . For example, if I was running into the wind, I just felt like I was a much bigger target for the wind to catch.' (Dominic) 'It's pulling me back . . . I'll probably hunch forward a bit to counteract it, because I do tend to get shoulder ache.' (Lisa) 'Initially, it's just having that extra weight and even that slight kind of constriction around your torso. Changes the way you breathe. So it's almost kind of having to re-teach my shoulders to relax.' (Mia) There are a range of rhythms visible here that run-commuters explain are knocked out of kilter by the addition of the bag. Many found bags, their weight, straps and materiality to be restrictive to their usual bodily movements. They are unable to access the usual range of movements they typically can, restrictions to their kinaesthetic and proprioceptive systems, and report a loss of freedom in their motion because of it. Others reported changes to their bodily form and rhythm to accommodate the bag, such as hunching forward. For me, I find running with a bag affects the bounciness of my gait, I run flatter as my body adjusts to the bag. Moreover, biological rhythms were also affected with some reporting a retuning of the respiratory rhythms to acclimatise to the bag, while others reflected the increased stress on the cardiovascular and muscular-skeletal rhythms, as they are required to work harder due to the additional weight of the bag. It is clear that, as a mobile prosthesis, a bag causes arrhythmia within the polyrhythmic ensemble of the runner, something that could be thought of as a disorienting experience (Bissell & Gorman-Murray, 2019), initially at least. We sense from these quotes that runcommuters' usual flows and rhythms are becoming undone by the mobile-material encounter with a bag. They are losing their orienting relations to the movements of running through this encounter leading to a discoordination or possible disintegration of usual rhythms (Bissell & Gorman-Murray, 2019). As such, running with a bag is often perceived as an encumbrance or constraint with negative effects on the experience of run-commuting. This is not a one-way agency however. The bag does not only effect but is also affected by running too as body-object configurations spring into motion. Running imparts a rhythm onto the bag, forcing it to move and respond to the motions of the wider runcommuting assemblage. The bag's rhythm is often incongruous with other running rhythms, causing the eurhythmic state to be strayed from: 'It would just bounce up and down . . . if it was moving about . . . I'm having to hold the strap, which means my arms aren't moving. It's just not a comfortable motion.' (Dominic) There are cacophonous rhythms here. The bouncing and jangling of the bag as the body's rhythms force it to move while still docked to run-commuters' backs causes disruption and displeasure. Although generally comfortable when stationary or walking, the bag can become at odds with the body when experiencing the intense embodiments of running. Particularly for large or ill-fitting bags, there is almost an inverse call-and-response relationship between the rhythms of bags and bodies, where a bag reacts with equal yet opposite force to the runner, as though being repelled by a magnet. Dominic's holding of the strap is an attempt to bring the bag within his own force and field of motion, a rhythmic tactic explored further in the next section. Such cacophony speaks to the mutability of mobile objects (Bissell, 2009), which change shape when on the move and inscribe themselves onto the body in doing so.
Two inscriptions in particular were reported by run-commuters as an outcome of the cacophonous bag and body rhythms -one caused by friction and the other heat: 'My first run-commute was with a huge backpack on . . . the thing that I noticed was I got like chafing around my neck. As it would bounce up and down, it would rub and you do a run and you get a blister' (Sam) 'It smells really offensive. Doesn't matter how many times I wash it. It's like, I wouldn't wear kit that smelt that bad. I'd throw the kit away. But I can't afford to throw away a £100 bag.' (Lisa) The impressions the disruptive rhythms of the bag can have on a runner can be painful and enduring, as well as sensually uncomfortable, particularly in regards to thermoception (see, Allen-Collinson & Owton, 2015; Hockey & Allen-Collinson, 2019). But here we also see the co-constitution and affective materiality of both bodies and objects. The heat caused from the weight, friction and lack of ventilation involved in wearing a bag can cause sweaty bodies, which impart odours and aromas back on to the bag. As expressed by Lisa above, these affects extend beyond the run itself, and can cause onward issues when bags are then taken into work or public transport spaces. While in exercise cultures sweat may illustrate self-care and athletics ideals (Waitt, 2014), in work spaces, particularly white-collar ones, sweat is embedded in different symbolic registers (Waitt & Stanes, 2015). The sensations of sweat -the sight, touch and smell of it -are often pathologised, seen as going against workplace etiquettes and the 'social and gendered norms regarding professional work appearance' (Lee, 2016, p. 415;Waitt & Stanes, 2015). The impressions runners and bags make on one another can be affective and lasting. As a body-object assemblage, runcommuting can be a disruptive, uncomfortable and unenjoyable experience. The normal eurhythmia of running can be sent into arrhythmia as the polyrhythmic ensemble is affected by and seeks to accommodate an additional object and its weight, materiality, rhythms and constrictions. This does not appear to be a particularly harmonious concert of rhythms showing the materiality of bags to be constraining to run-commuting experiences.
However, most run-commuters find running with a bag a tolerable thing. Although no one declared a liking for running encumbered in this way, most spoke of becoming accustomed to running with a bag: 'I'm so used to it. I don't really think about it anymore. Initially, I was, oh yeah, bit more aware of it but not anymore.' (Callum) 'Oh yeah. We've got to know each other.' (Mia) This could be considered as an alternative eurhythmia, where a similar rhythmic quality to ordinary running has been reached, just at a different pitch. Although the differences to ordinary running rhythms and experiences are easily perceptible (and often negative in comparison), a different eurhythmia has been settled on when running with a bag as the body and the bag have 'got to know each other'. This is a form of fluid apprehension important in everyday mobile encumbrance (Bissell, 2009) and could also be contemplated as a transformation habits. In this way, past actions feed into future ones, where 'all movements stretch beyond themselves to condition future movements' (Bissell, 2014b, p. 488 emphasis in the original). Drawing on Ravaisson, Bissell (2014b), argues that with repetition and time, habits transform movements and develop competencies. Movements once awkward, uncomfortable and disjointed become smooth, tolerable and unremarkable. Through habit, runcommuters can become accustomed to running with a bag, and in doing so, develop the skills and rhythms needed to cope with this additional stimulus in the intense embodiment of running.

Managing rhythms
To speed up this process of becoming accustomed and minimising the disruptive effects of bags, most run-commuters also spoke of making amendments to the mobile prostheses and wider assemblage in attempts to manage these rhythms. Once more, Bissell (2009) offers an instructive way to think about this. Drawing on de Certeau and Ingold, Bissell (2009, p. 176) puts forward the idea of tactics to consider the 'practical knowledge that, through repetition, develop into skills and techniques for moving'. As such, these act as a form of feedback loop in the polyrhythmic ensemble of run-commuting, where practitioners alter their bodyobject configurations to produce more harmonious rhythms. These are processes rather than one-off events. As research from disability studies shows us, getting used to mobile prostheses is an ever-unfolding task involving the 'mutual shaping of people and devices through adjustment' (Winance, 2006, p. 52). Much like the 'creative process of re-embodiment experienced by physically disabled adults who become wheelchair users' (Papadimitriou, 2008, p. 691), achieving tolerability in new body-object configurations for run-commuters often requires continual labour and adjustment. There were three main tactics run-commuters in this project employed to enhance the embodied experiences of running with a bag: speed, bag choice and packing.
The first tactic is to dampen the impacts of running on the bag by running more slowly. The rhythms of slower running are more gentle waves than the staccato-like rhythms involved in running quickly. With milder forces being imparted on to the bag on the runner's back, the rhythms with which it moves are less abrasive, bouncy and jangly, leading to more tolerable experiences: 'I'm not conscious of it as like every single step of the way, but I'm certainly aware I'm wearing it. But I don't feel like it's slowing me down . . . But yeah, it's not a big thing and that's partly why most of those runs are not like fast runs when I've got a bag on. I definitely wouldn't take a bag on a training run if I don't have to.' (Sam) This tactic may actually be more an accidental one. The impetus for running slowly in runcommuting often stems from a desire to minimise energy-output and sweatiness, especially important for those who run to work in the morning and may lack shower facilities. This not only ensures the day ahead can be more easily transitioned to and endured, but it also reduces the risk of overloading and injury that concerns some more frequent runcommuters. However, knock-on benefits for managing the disruptive rhythms of running with a bag are clearly noticeable and enjoyed. Altering the intensity of the rhythms at play in run-commuting can minimise the incongruent rhythms of bag-use.
The second tactic is one of bag choice. This is mostly a choice about design and a burgeoning research field has begun to demonstrate the importance of design on the taking place and experience of mobilities (Jensen et al., 2020). However, this work has generally explored larger-scale designs -the designs people may move within (e.g., urban or station design) or on (e.g., bicycle or car design) -rather than the smaller-scale design of objects that may move with people. For run-commuters, the design of the bag can be crucial in developing eurhythmia and mediating relationships between bodies and prostheses. Many run-commuters have used multiple different bags for run-commuting, in the hope of producing better experiences through design. A bag designed specifically for running, or even run-commuting, seemed crucial to producing better embodied experiences for most run-commuters. When asked what affordances they offered compared to other bags, participants in this project revealed a range of design elements they appreciated: 'It's to keep the bag locked down. It's to keep me feeling comfortable whilst locking the bag down . . . Lightweight. As light as possible. Minimalist . . . Ventilated . . . Reflectivity as well. And really just the design of it. It locks down without being uncomfortable, but it provided a secure fit.' (Dominic) 'It's really kind of held very close to the body and it's got 3 straps. So it really forms part of you -It's almost like an extra layer of clothing, in a way.' (Sam) As well as other useful features related to the storage capacities and safety a bag can offer, there are various design elements visible here aimed at minimising the disruptive nature of bag-use rhythms. Straps are perhaps the most significant feature. A combination of shoulder straps, waist straps and chest straps 'lock down' bags very close to runners' bodies. In doing so, the cacophonous rhythms of bags and bodies colliding into one another are nullified as the running-assemblage moves as one rhythmic entity. Bodies and prostheses are no longer competing and the bag begins to form part of run-commuters, as Sam explained and seen in Dominic's strap-holding earlier. The importance of bag straps on the experience of run-commuting cannot be understated. Straps effectively force the runner's rhythms onto the bag, rather than having its own, and with a bodyobject assemblage that moves together, friction, irritation and heat are simultaneously reduced. A reduced size, weight and the design of ventilation features also helped in this endeavour. Together, the design features of specific running bags helped to smooth the disruptive rhythms experienced during bag-use and in doing so, help alleviate some of the negative affectivity of bags.
The precise design desired varies between run-commuters but the general design needs of the running body-object assemblage has led to the development of new bags pitched directly at run-commuters. This is evidence of the increasing commercialisation of runcommuting that has been visible in recent years (Cook, 2020a), something lamented by a few participants in this project: 'Running is meant to be kind of a low-cost activity so I don't like the commercialisation of it -the companies that are charging £200 for a running bag' (Callum). The tactic of bag choice, thus, is an important one in run-commuters managing to run happily with bags but is one that can present financial barriers.
The final key tactic employed by run-commuters involves developing the skills of packing to help alleviate the cacophonous rhythms of bodies and bags. Bag-packing is a valuable practice to analyse in mobile material cultures (Barry, 2017) and plays an important role here, with the microgeography of bags and their internal rhythms relating to the experience and logistics of run-commuting.
So far, I have discussed the bag as a single object. This is not truly accurate as a bag is itself a container for a variety of other objects. Just as bags have rhythms forced upon them when attached to a running body, the contents of bags are forced to move as well. They can bounce and rattle around in accordance or discordance with the rhythms of running, impressing back on one another as they vibrate, crease, bend, collide and mush together with often undesirable outcomes. The mutability of mobile objects seen here can affect running bodies too as the arrhythmia of moving objects hit, irritate, poke, weigh-down and aggravate runners' bodies. The role of packing was important to run-commuters in curtailing this and many participants discussed the development of this competency: 'I think I've learned how to pack it so you just don't have things jagging in your back.' (Oliver) 'It's packed pretty well, generally. Occasionally I've had slightly crumpled shirts, more crumpled than I perhaps like but not too bad . . . I've got better at [packing] . . . I think it's kind of rolling it into a kind of cylinder, almost. Fold and then roll it. That's the way I do the shirts.' (Malcolm) Again here, we see attempts to make the multiple objects in a bag move with only one harmonious rhythm, all in accordance with each other. There are also techniques that change the form of these objects so they are less affected by the vibrations and pulsations of run-commuting, such as rolling clothes to reduce unwanted creasing. This development of packing skills helps to improve the embodied experiences of running with a bag by harmonising the arrhythmia of objects within the bag, diminishing the negative impacts on bodies they are moving with and the objects themselves. These were skills reported by all asked in the project, often accompanied with a narrative of refinement and fine-tuning. As such, packing is a key competence for many in their run-commuting practices and demonstrates how run-commuting is more widely enmeshed with other rhythms of work, home and everyday life. Packing skills are not usual competencies of running practices and this further highlights run-commuting's blurry position, caught between a mobile practice related to utility, commuting and work, and one related to sport, exercise and leisure.

Conclusion
This paper has attempted to bring to life the previously unresearched experiences of runcommuting by exploring one of the defining aspects of the practice -running with a bag. This is a distinguishing feature of, yet also a major barrier to, run-commuting participation, so better understanding these experiences and how they can be made more pleasurable or manageable is important in helping to facilitate the practice. As an active travel mode growing in popularity that can help people maintain running habits amongst the competing rhythms of everyday life and benefit society more widely through reducing physical inactivity and transport pollution, run-commuting is a promising and important activity to attend to. I have done so in this paper by drawing on, and extending, social and cultural geography's interests in mobile and sporting practices, affective materialities, and rhythms to explore run-commuting as a new mobile body-object configuration, and the experiences and impacts of this.
Generally, running with a bag was not an overly pleasurable experience for runcommuters. Some reported severe dislike but most described a tolerance for it, accepting bags for the facilitation they offer their practice. The addition of bags to runners' bodies affected experiences by not only intensifying embodiment with new stimuli, but also contributing new rhythms to the polyrhythmic ensembles of runners. These rhythms were often disruptive and constricting, altering the ordinary eurhythmia of bodily movements, breaths, heart rates, and form. They were also disruptive through the rhythm of the bag itself, banging, jangling and moving in discordance with the body it is anchored too. The weight, friction, temperature and abrasions caused by the competing rhythms of bags and bodies often imprinted themselves onto runners' bodies, negatively affecting experiences. However, most run-commuters discussed a process of becoming accustomed to running with a bag. Through experience and habit, runners' bodies develop capacities to deal with the cacophonous stimuli of running with a bag, something aided by the simultaneous development of competences and tactics to manage moving with this mobile prosthesis. Together, bodily capacities, bag choice, packing skills and speed changes led to rhythmic retuning, altering run-commuting experiences to the point where running with a bag was mostly tolerable. This could be seen as the alternative eurhythmia of running with a bag.
Running with a bag extends run-commuters bodily capacities for load bearing but at the same time can curtail the pleasures and movements of running. Running with a bag is both a facilitation and an encumbrance that mediates and transforms the embodied experiences of run-commuting in a multitude of ways that come to light with a receptivity to materiality and rhythm. Paying close attention to bodies on the move and their material accoutrements, as I have done in this paper, helps advance social and cultural geography's interest in the embodied experiences of everyday movement by considering mobile-body-material relationships at more intimate and intense scales. It places bags and other encumbrances more firmly on the agenda in studies of mobility and sport too. While a wide range of mobile materials have been researched and politicised -such as shoes (Adey, 2020), waste (Davies, 2012), and life jackets (Barry, 2019) -bags have yet to receive similar treatment despite being ubiquitous everyday encumbrances.
The analysis offered here points to valuable ways of further exploring bag-use and materials in mobile cultures more widely. Beyond their enabling or constraining functions, this work has demonstrated the importance of paying attention to how body-object configurations generate embodied, sensory, kinaesthetic, symbolic and rhythmical (dis)pleasures. In particular, the application of rhythmanalysis to mobile materials offers valuable insights at the intersection of design, material and mobility thinking into affective materiality, the lived experience of objects and the impacts they have. Being attuned to such impressions that moving bodies and things make on each other has also brought into view a variety of specific mobile material practices -such as packing, adjustment, design -that not only form integral parts of mobile cultures but help to manage and sustain (or endure) practices too. Sensitivity to mobile-material relations also reveals the politics they are bound up in, highlighted here through the lamented commercialisation and cost of run-commuting bags. As work in disability studies makes clear, the relationships between mobility and things are anything but trivial and warrant further sustained study, exploring what is it like to move with/against materials, and the social, political and cultural implications of these. This paper has pointed to multiple ways forward for geography, mobility and sport studies in this regard, and urges more substantive engagement with mobile material cultures in the future.
The approach adopted in this paper also helps advance rhythmic thinking in these fields. Through a focus on bodily rhythms, this paper contributes to the energising, embodying and enlivening of rhythmanalysis. By attending to the rhythms of runcommuters' cardiovascular, respiratory, muscular-skeletal, kinaesthetic, thermoreceptive and proprioceptive systems while running with a bag, this paper takes seriously the fleshy, internal, biological, somatic and corporeal rhythms of bodies on the move that has generally overlooked in rhythmanalysis so far (Larsen, 2019), highlighting their significance for mobile and sporting practices.
Understanding sporting, mobile, material and rhythmic experiences in these ways not only helps us comprehend practices like run-commuting further but we can also better understand how participation in them is facilitated and constrained. As an active, healthy and sustainable mobile practice, run-commuting has much potential that warrants promotion. Yet, running with a bag presents a significant barrier for many in commencing run-commuting. This study reveals how through logistic routines, habit, packing and bag choice, run-commuters manage to overcome this barrier and run-commuting practices can be enabled.

Ethics declaration
The research included in this paper received ethical approval from Royal Holloway, University of London. All participants provided appropriate informed consent, which was obtained in writing by the researcher.