An Updated Review of Interventions that Include Promotion of Physical Activity for Adult Men

The marked disparity in life expectancy between men and women suggests men are a vulnerable group requiring targeted health promotion programs. As such, there is an increasing need for health promotion strategies that effectively engage men with their health and/or illness management. Programs that promote physical activity could significantly improve the health of men. Although George et al. (Sports Med 42(3):281, 30) reviewed physical activity programs involving adult males published between 1990 and 2010, developments in men’s health have prompted the emergence of new sex- and gender-specific approaches targeting men. The purpose of this review was to: (1) extend and update the review undertaken by George et al. (Sports Med 42(3):281, 30) concerning the effectiveness of physical activity programs in males, and (2) evaluate the integration of gender-specific influences in the content, design, and delivery of men’s health promotion programs. A search of MEDLINE, CINAHL, ScienceDirect, Web of Science, PsycINFO, the Cochrane Library, and the SPORTDiscus databases for articles published between January 2010 and August 2014 was conducted. In total, 35 studies, involving evaluations of 31 programs, were identified. Findings revealed that a variety of techniques and modes of delivery could effectively promote physical activity among men. Though the majority of programs were offered exclusively to men, 12 programs explicitly integrated gender-related influences in male-specific programs in ways that recognized men’s interests and preferences. Innovations in male-only programs that focus on masculine ideals and gender influences to engage men in increasing their physical activity hold potential for informing strategies to promote other areas of men’s health.


Introduction
Epidemiological evidence clearly supports the role that physical activity plays in health promotion and disease prevention. Regular physical activity (which includes exercise) reduces the risk not only of premature mortality, but also coronary heart disease, hypertension, some cancers, type 2 diabetes, high body mass and mental illness [1][2][3][4]. These benefits extend beyond primary prevention, and when combined with other healthy lifestyle behaviors (e.g., healthy eating), can add up to 14 years to life expectancy for people living with chronic disease [5]. This is particularly important for men, who, compared to their female counterparts, are more likely to have a shorter life expectancy and experience higher mortality rates associated with chronic disease [6][7][8]. Despite the health benefits associated with physical activity, research has highlighted that an alarming proportion of men do not engage in the recommended levels of physical activity (150 min or more of moderate intensity physical activity per week) for optimal health benefits [9,10]. Globally, approximately 28 % of men are insufficiently active, with the highest prevalence in the Americas (40 %) and Eastern Mediterranean regions (36 %) [11]. Recent interest in men's health, particularly in relation to addressing and preventing obesity, has led to a number of reviews outlining effective approaches towards risk reduction through active living and healthy eating [12][13][14]. Within these reviews are well-defined considerations around effective modes of delivery and the use of behavioral theory to support adoption of these behaviors.
Health professionals routinely point to males as a 'hardto-reach' population wherein unique challenges reside for implementing illness prevention and health promotion initiatives such as physical activity [15][16][17]. Specifically, males are less willing than their female counterparts to have an annual health check or seek advice from a health professional, less willing to attend health education sessions, and are less interested in information concerning illness and disease prevention compared to women [15,[18][19][20][21][22]. In terms of research, a clear gap remains in which little male-specific research concerning health promotion is available. Intervention research addressing physical activity has predominately included female samples [23][24][25][26], making it difficult to translate these outcomes to males. These inequities are even more pronounced among subgroups of men (e.g., low socio-economic status, Aboriginal, immigrant men) and raise questions concerning sex and gender influences in developing targeted approaches to men's health promotion programs and interventions [27].
Although researchers have examined the effectiveness of physical activity interventions [28], few have focused on program effects by sex or considered the influence of gender-related factors [29]. One recent review by George et al. [30] provided a critical evaluation of studies examining the effectiveness of physical activity programs in adult males. They found that only a limited number of physical activity interventions targeted men specifically. Although promising modes of delivering programs to men were associated with improved male participation rates, retention, and increased overall success, there was little focus on examining physical activity interventions for men in relation to the influences of gender and the role of masculinities. Theories of masculinity and increasing attention to sex and gender influences on health and health behavior have prompted explorations and new understandings of men's health in recent years [31,32]. These developments have led to the emergence of new sex-and gender-specific health promotion approaches targeting men [15,33].
The two-fold purpose of the current review was, therefore, to: (1) extend and update the work undertaken by George et al. [30] concerning the effectiveness of physical activity programs in males, and (2) evaluate the integration of sex-and gender-related influences in the content, design, and delivery of these men's health promotion programs.

Literature Search Methodology
A comprehensive review of physical activity programs involving men was undertaken between January 2010 and August 2014. The databases MEDLINE, CINAHL, ScienceDirect, Web of Science, PsycINFO, The Cochrane Library, and SPORTDiscus were searched using all combinations of the terms 'male or men' with 'physical activity, exercise, or sport' and 'intervention, program, or trial'. No unpublished or grey literature was searched. Two research assistants (KM and HJH) completed the initial search and a project coordinator (CS) oversaw the process to ensure the search strategies and exclusion criteria were consistently followed.
Replicating George et al.'s [30] inclusion criteria, we used the following criteria to identify articles for this review. All study designs were included (e.g., randomized controlled trial [RCT], pre-post, quasi-experimental, etc.) provided they met the following: (1) included only male participants or data that was disaggregated by sex; (2) all participants were aged 18 or older; and (3) at least one of the outcomes of the study was a change in physical activity (and exercise) or a measure of biomarkers of disease related to a change in physical activity (e.g., body mass index [BMI], blood pressure, waist circumference). Articles that included both physical activity and other health behaviors (e.g., diet) were included, provided they met the aforementioned criteria. Only articles published in English were considered. Additionally, articles with participants who were solely 65 years and older were excluded. If more than one article was published based on the same sample of participants, the most relevant article was retained for this review (no secondary publications).
Our search yielded a total of 21,446 articles and resulted in 7,354 articles after duplicates were removed using RefWorks. A title and abstract review was conducted (KM and HJH) to exclude articles that did not meet the eligibility criteria. In total, 213 articles were identified for further assessment, and the full texts of these articles were reviewed (KM and HJH). After excluding articles that did not meet the inclusion criteria (e.g., did not report results separated by sex), as well as those that were based on the same sample (n = 4), 31 articles were identified for inclusion. The reference lists of the articles that met the inclusion criteria were examined, and of the additional 1,595 articles evaluated, four met the inclusion criteria. A flow diagram summarizing article inclusion/exclusion is provided in Fig. 1. Altogether, the search resulted in 35 articles identified for inclusion: 13 articles reported on evaluations of programs focusing on physical activity only (Table 1), and 22 reported on evaluations of programs that included both physical activity and other health behaviors (e.g., healthy eating) ( Table 2). In the presented results, programs that were evaluated in more than one study were counted once in summaries of program details.

Findings
The 35 studies included in this review involved 31 different programs and a total of 14,383 male participants (sample sizes from 24 to 4,870). It is also important to note that seven of the 35 studies reported the results of pilot programs.
The majority of the studies (n = 24, 69 %) evaluated programs that were only offered to men. Male-only programs were offered in 7 of the 13 studies that evaluated physical activity only programs (duration 8 weeks to 2 years). Of the 22 studies that included programs designed to enhance physical activity in combination with other health behaviors (duration 7 weeks to 5 years), 17 had male-only samples. The primary outcome of interest in the present review was change in physical activity, but   and body fat significantly more than those in the control group. They also improved their diet and psychological outcomes   secondary outcomes indicative of changes in physical activity were also of interest. Among the studies meeting the inclusion criteria (n = 35), 24 reported significant increases in men's physical activity  and three reported no changes in physical activity [58][59][60]. For the remaining eight studies, changes in physical activity could not be determined because this was not directly assessed as an outcome variable [61][62][63][64][65][66][67][68]. However, in these studies changes in secondary measures (e.g., cardiovascular health, metabolic factors) suggested positive changes in physical activity. Of the 35 studies reviewed, 12 involved follow-up assessments at time points after intervention completion (ranging from 7 weeks to 15 months post-program end) [34, 40, 45, 46, 48-50, 57, 58, 60, 61, 66]. All but two [58,60] of these demonstrated successful maintenance of physical activity and/or secondary measures indicative of positive changes in physical activity; however, follow-up durations were primarily shorter: in nine studies the followup was conducted less than 1 year following the conclusion of the program [34, 40, 45, 46, 48-50, 58, 66], in two studies follow-up assessments were conducted 1 year after the program conclusion [57,60], and in one study the follow-up was conducted at 15 months after the program conclusion [61]. Because some of the included articles were separate studies based on the same program (e.g., Healthy Dads, Healthy Kids), the findings are reported based on the 31 distinct programs, rather than the 35 articles. In total, 28 of the 31 separate programs were successful in increasing either physical activity or a secondary measure indicative of increases in physical activity. The findings are summarized below organized according to theoretical approach, mode of delivery, strategies for physical activity promotion, and gender-sensitive programs.

Theoretical Approach
Of the 31 different programs, 14 explicitly described theoretical perspectives guiding behavior change approaches [34, 38, 40, 41, 48-50, 52, 55, 57, 58, 68-70], the most common being social cognitive theory [71], which guided 12 different programs, often in combination with other theoretical approaches. Overall, theoretical constructs were measured in three of the studies reviewed. Andersen et al. [34] found that social support, self-efficacy and outcome expectancies among men increased in the program group compared to the control group; however, the changes in these social cognitive constructs were unrelated to changes in physical activity. Although Gram et al.'s [69] program was not explicitly based on the theory of planned behavior [72], post-intervention interview data suggested program adherence (exercise behavior) fit within a theory of planned behavior model (i.e., positive attitudes about exercise, a sense of obligation or social pressure, and perceptions of control about ability to succeed influenced exercise behavior). Finally, although the theory of planned behavior did not guide Sheeran et al.'s [40] program, they found that constructs from the model helped explain how mental contrasting enabled participants to more effectively translate their attitudes about the importance of physical activity into action (i.e., engaging in physical activity) compared to a control group.
In some programs a variety of resources were also used to support program delivery (e.g., print-materials, DVD, tracking tools, regular personal reports on adherence; email prompts/motivational messages). Web-based platforms were among the more innovative approaches used for elements of program delivery and also formed a medium for self-monitoring and peer support. In total, eight different programs were evaluated that involved internet components [44, 50-52, 55, 59, 60, 66, 70]. Within these programs, variability existed in how the internet was utilized. For example, in a weight loss program, the Self-help, Exercise, and Diet using Information Technology (SHED-IT) program [50,66], the online enhanced delivery approach included a website directory, online food and exercise diaries, and feedback emails and was compared with a group that received a print-based resource. In five other programs the internet was used to facilitate monitoring of physical activity and pedometer data, food intake, and/or weight [44,52,55,59,60]. In one of these internet programs, family members and counsellors were also able to view and comment on progress [59]. In another, an interactive website and mobile phone web app provided a medium for connecting with male peers as a means of promoting social support and friendly competition [55]. The internet was also used as a medium for friendly competition in a corporate team-based program where teams of men and women were able to compare their progress and communicate with team members using a virtual platform [44]. Taking full advantage of the opportunities to develop computer-tailored individualized programs, one group designed a low intensity energy balance online program for recent male retirees (average age 59.5 years) to provide tailored advice. However, full exposure to the program was low in that less than 50 % of participants in the program utilized the online modules and resources [60]. In contrast, engagement in a 12 month, web-based program for overweight and obese men was more encouraging [52]. This program was specifically tailored to men's preferences and was flexible. For example, men made their own choices regarding behaviors to work on at any particular time. On average the men in the program (average age 43.9 years) logged onto the website to set weekly goals for 23.4 weeks (SD = 16.7) over the duration of the program.
The setting was also identified as an important consideration in engaging men in physical activity programs. In this review there was a marked increase in the types of entry points and strategies for engaging men in physical activity compared to the studies reported by George et al. [30]. A few researchers leveraged the workplace as an intervention location [39,44,51]; however, four other programs to support men's physical activity traded on men's interest in sports by engaging men through their affiliations with organised sports and delivering group exercise sessions at local sports clubs [45,46,53,54,61,67]. One additional program did not actually engage men in group exercise, but did recruit participants through a local angling club [40]. Although incentives were offered in a few programs-such as free access to a gym [42] and group-based financial incentives [51]-friendly competitions or challenges were also used to engage and motivate male participants [38,44].
In the few studies that were not successful in demonstrating significant increases in physical activity, the programs varied considerably [58][59][60]. One similarity among these was that all used an individual approach, recommending participants engage in physical activity on their own. Maruyama et al. [59] noted that environmental barriers (e.g., lack of access to exercise facilities) may have led to their null results and suggested that such barriers may need to be addressed in future programs. Indeed, other programs that used an individual approach and provided free access to facilities were successful in increasing men's physical activity [42].

Physical Activity Promotion: Techniques and Approaches
The programs included in this review were based on various physical activity recommendations. For example, some programs encouraged participants to engage in 30 min of physical activity per day [41,57,67,68], whereas in others participants were asked to increase their step count to 10,000 per day [42,44,52,56] or aim for 10 miles of fast walking or jogging per week [64]. All programs focused on increasing cardiovascular or aerobic physical activity, and a few also included strength-building exercises [34, 45-47, 55, 57, 70]. In one program, participants' adherence to the strength-building guidelines of two or more days per week was evaluated, and although intervention participants engaged in more moderate and vigorous activity compared to the control group, they did not differ in terms of strength-building activities [57]. Overall, the suggested amount of recommended moderatevigorous physical activity ranged from 50 to 250 min per week.

Gender-Sensitive Physical Activity Programs
Though 20 of the programs were offered exclusively to men, it did not appear that sex or gender-related factors informed the design or delivery in eight of these programs [34,39,40,42,43,56,59,69]. In the majority of cases, the programs were tailored to theory-based considerations (e.g., self-efficacy, social support) or personal risk estimates, and based on accepted recommendations regarding physical activity for healthy adults. If face-to-face counselling was used, gender-neutral strategies, such as goalsetting and providing advice, predominated [34, 39, 42, 43, Physical Activity Interventions for Men 793 59]. However, the remaining 12 programs offered exclusively to men demonstrated an emergence of innovative approaches to promoting physical activity that acknowledge men's interests and preferences (i.e., that are gendersensitive) in a variety of ways. What is common among these programs [38, 45, 46, 48-55, 57, 61, 66, 67, 70] is that they are designed from the ground up as sex-specific and gender-sensitive programs. Four similar programs to encourage participation in physical activity by drawing on men's interest and involvement in football (commonly referred to as soccer in North America and Australia) were evaluated and found to be highly successful in increasing physical activity as well as other health behaviors [46,53,54,61,67]. These programs were based in England, Scotland and Australia where football/soccer has a long-standing and dedicated male fan base. Delivered through football/soccer clubs, the programs engaged coaching staff at the clubs or qualified trainers and involved men in a variety of group exercises. Football Fans in Training (FFIT) [45,46], an example of this approach, offered a 12 week ''gender-sensitized'' program focused on weight loss, physical activity, and healthy eating advice to overweight and obese men and demonstrated improvements in self-reported physical activity and healthy eating. Underlying the success of this approach is men's familiarity and comfort with the setting (i.e., football clubs) and an approach that works with masculine ideals rather than against them. Designed to be appealing to male football fans, the FFIT program included club-based incentives (e.g., club T-shirts, visits from club celebrities), friendly competition, education related to alcohol consumption, and the use of ''banter'' in discussions of sensitive health issues (e.g., weight gain) [45]. Comparable programs delivered in the UK and Australia also produced encouraging results [53,54,61,67].
An Australian based group has developed three programs-each with unique aspects and program names designed to appeal to men. The SHED-IT program was specifically designed to promote healthy lifestyles and facilitate weight loss among men [50,66]. In recognizing that men were not attracted to structured, face-to-face programs, alternatives were developed that would not involve face-to-face contact. The SHED-IT resource package consisted of DVDs and handbooks along with a pedometer, tape measure for waist circumference, and a kilojoule counter book. Access to an online food and exercise diary site was also provided to one group of SHED-IT participants to assess the efficacy of the paperbased resources compared to augmenting resources with the online support [50]. Although the SHED-IT program was based on Bandura's [71] social cognitive theory (e.g., self-efficacy, self-management, perceived barriers, and social support), the resources were tailored specifically for men, utilising dynamic culturally sensitive language affirming masculine virtues in order to engage Australian men (e.g., ''Weight Loss Handbook for Blokes''). A lighthearted and sometimes humorous approach to physical activity and dietary behaviors was used to reflect men's applied and active approaches amid ensuring autonomy in establishing their own goals for the program. In these and other ways, the messages, their delivery, and affirmation for participating avowed an array of masculine virtues. Although the pilot study results for SHED-IT [73] were reported in the previous systematic review by George et al. [30], subsequent RCT results indicate that the online and the resource-based programs were equally effective in improving physical activity and promoting weight loss compared to the control group [50].
The second program, Preventing Obesity Without Eating Like a Rabbit (POWER), was a workplace-based weight loss program designed to engage overweight and obese male shift workers [51]. Modelled after SHED-IT, the Workplace POWER program was tailored for shift workers and included information sessions or DVD resource, an interactive study website, and group-based financial incentives to improve healthy lifestyles with respect to physical activity and healthy eating. Workplace POWER was a men-only program, and the setting, mode, and delivery mechanisms were designed to appeal to men. The use of prescriptive rules about diet was avoided. Instead, core messages were about how to fit in more physical activity and healthy eating with minimal disruption to daily life and assurances that they didn't have to give up things (e.g., beer and wine) to lose weight. Results indicate that the Workplace POWER program was effective in decreasing body weight and increasing physical activity.
The third program developed and evaluated by this group of Australian researchers was the Healthy Dads Healthy Kids (HDHK) program [48,49]. This program was a 7-week healthy lifestyle program designed for overweight/obese fathers and pre-school children delivered in community settings by trained male facilitators. Capitalizing on ideals related to fathering, healthy eating and physical activity were positioned as good ways for fathers to spend time with their children. In health-related information and physical activity sessions that traded on men's interest in being good fathers, men were provided with the knowledge, skills and encouragement to model health behaviors in their role as fathers. In addition to physical activity sessions for fathers, several group sessions involved both children and fathers, focusing on aspects of father/child activity such as rough and tumble play and fun and interactive games. The face-to-face program was supplemented with resources including a physical activity handbook, a weight loss handbook for men, and a website to support self-monitoring of weight, exercise and dietary intake during the program. The program demonstrated improvements in physical activity and other health behaviors among both fathers and children.
Another Australia-based program, ManUp, was a 9-month information technology-based intervention to promote physical activity and healthy eating among middle-age males [55]. In this program ''ManUp Challenges'' to increase levels of physical activity and healthy eating were offered using web and mobile phone based technology. With these challenges, men were provided with educational materials, tools for goal setting and selfmonitoring, and automated feedback on progress. To cater to varying levels of physical activity and dietary habits, build confidence, and provide opportunities for progressive changes, men could choose ''light,'' ''mid'' or ''full'' strength ManUp challenges. In addition, the intervention was designed to encourage online social support by providing participants with the opportunity to view and comment on the progress of others, and challenge their friends. Similar to the SHED-IT program, the information-technology and the print-based intervention arms of the ManUp program were equally effective in improving physical activity among men.
Another program was a 3-week health promotion intervention specifically tailored for South African men (18-45 years of age) [57]. In small groups of 9-15, the short community-based program was delivered by a male facilitator in the native language (isiXhosa) and involved male-centered activities. For example, the sessions began with a ''circle of men'' to foster a bond as ''brothers'' where participants could express their feelings openly and without judgement. The sessions also involved interactive activities with games, role plays, and videos focused on improving physical activity, fruit and vegetable consumption, and reducing alcohol and fat intake. Men also practiced strength-building and aerobic exercises to increase self-efficacy and were encouraged to engage in a combination of these exercises on a weekly basis. Lastly, the men participated in a brainstorming activity which focused on what it means to be a man and how men can influence their own health as well as the health of their families and communities. Although brief, this program was effective for increasing men's physical activity at 6 and 12 month follow-ups compared to a carefully matched control group.
The remaining three examples of gender-sensitive programs were based in the US. The first, a 1-year internetbased weight loss program for men [52], was based on social cognitive theory, feedback from focus groups conducted with men, and interviews with two experts in men's weight loss. The program was tailored to men's preferences for a focus on ''the facts'' (and not feelings) and a ''to-do'' list with links to more detailed information underpinning the program. In addition, short weekly web-based learning modules were designed using ''business like'' language and graphics and men were encouraged to set realistic weekly goals and report progress toward their ''to do'' list online. Autonomous decision making was also supported by allowing men to choose the behaviors to work on. Improvements in physical activity and diet were observed among those with the highest levels of adherence to the program. Finally, two innovative gender-sensitive pilot programs designed to engage African American men in physical activity were evaluated [38,70]. Hooker et al. [38] drew on previous research with mid-life African American men to integrate cultural and gendered components into a tailored 8-week group program to promote physical activity behavior change. Traditional views of masculinity and role perspectives were integrated into the program and reflected in concepts such as responsibility, stress management, and relapse prevention. In addition, activities to promote camaraderie were included as well as friendly team competition and a community service project. Men were assisted by the two trained facilitators to set overall and weekly physical activity goals, the majority of which were completed outside of the group sessions.
Also drawing on previous research with African American men [37,74,75] and informed by Hooker et al.'s [38] work, Griffith and colleagues [70] developed a community-based program called Men on the Move. Underpinned by social cognitive theory and self-determination theory, the aim of the program was to improve access to age and ability-appropriate, male-focused physical activity opportunities for African American men. Small group weekly workouts to foster male peer support and provide opportunity for modeling of exercise by other men of similar age were offered under the direction of a male fitness trainer. These sessions were augmented with information about community resources (e.g., schedule of fitness classes), handouts to guide home stretching and exercising, a list of helpful websites related to physical activity, and encouragement to contact others in the group to exercise together between sessions. The evaluation results of both of these pilot programs provide support for the feasibility of these new initiatives and potential for promoting men's health when programs address their needs and interests.

Discussion
The findings of this review extend knowledge related to promoting men's physical activity and provide directions for future research. Since the review conducted by George et al. [30], there has been growing interest in designing and evaluating programs to promote men's physical activity Physical Activity Interventions for Men 795 with 35 new studies published within the last 5 years. The majority of studies in this review reported significant increases in physical activity. It is possible these programs may also produce mid-or long-term changes in physical activity; however, the availability of only a few studies with long-term follow-up limits clear conclusions on sustained effectiveness [34,35]. The included studies were characterized by a wide variety of programs, many of which hold potential for increasing men's physical activity. This is consistent with previous work insofar as it points to the general effectiveness of programs that have some component of individual tailoring or that involve some degree of personal contact. However, given the multicomponent nature of these programs, it remains unclear what unique variability each component contributes to positive behavior change. The features of program delivery were, to a large extent, constrained by the features that authors typically report and that can be easily and objectively verified (e.g., whether email messages were used). There may be other important features that are not routinely collected or reported, or that are difficult to measure. As internet-based programs and smart-phone applications become more common, it should be relatively easy to integrate these additional delivery features into current programs-particularly for young and middle adult men who are familiar with these technologies. Nevertheless, despite the unique challenges of engaging men in health promotion and the gender-related factors influencing men's engagement in health behaviors [15][16][17], only 12 of the programs considered these factors in the design and delivery of approaches to promote men's physical activity.
The results of the current review indicated that overall, even with calls for theoretically-driven health promotion programs to enhance effectiveness [76], explicit linkages were only examined directly in three of the studies making it difficult to draw conclusions about the role of theorybased strategies for increasing physical activity among men. Furthermore, many different strategies supporting behavior change have theory-based underpinnings making it possible that programs without explicitly stated theoretical underpinnings also had an underlying theoretical basis. In the wider literature on physical activity interventions the potential role of either theoretical constructs or specific behavior change strategies is also rarely examined [77]. Others have called for more research to examine the potential mediating role of theoretical factors in the success of interventions [76,77], and it seems timely to also suggest that researchers ought to investigate the potential role of gender-related factors within the effectiveness of theorybased strategies for behavior change.
There may also be a need for new theoretical foundations for men's health promotion programs. Although the connections between sports and men's hypercompetitive and homosocial practices have been critiqued, men's willingness to do physical activity appears to be a central consideration to successful health promotion efforts [78]. Indeed, of all the facets of health promotion, physical activity prevails as most likely to engage men with their health [79]. In this regard, engaging men in physical activity draws upon as well as provides opportunities to garner masculine capital by affirming competitiveness and/or striving for physical prowess [80]. Oliffe et al. [81] name this as a strength-based approach to men's health promotion whereby rather than seeking to change men, some masculine norms (i.e., willingness to engage physical activity) are deliberately targeted to catalyze men toward self-health. Within the literature reviewed here it is fair to say that physical activity masculine norms are, at best, implicit. While this might be an oversight or triaged as relatively unimportant next to the empirical findings, there are good reasons to cultivate the principles underpinning men's involvement with physical activity based health promotion. For example, men's health promotion program design may be reliably informed by what has worked for others as well as why that might have been the case. Conversely, much can be learned about what to avoid by distilling what fails to invigorate men in the context of physical activity centric health promotion programs (e.g., mixed gender programs, group versus personal trainer models). In this regard, the barriers to men's engagement along with principles underpinning participation should be understood as carrying equal empirical weight. After all, these collective insights are key to advancing the application of health promotion theories to men-centred program design.
In the present review, the mode of delivery of physical activity was integral to the success of a program at increasing physical activity. It is noteworthy that all studies that involved men engaging in physical activity with other men through professional sports resulted in increased physical activity. Although group exercise was limited to 1-2 h per week, men may have gained the motivation to exercise individually from these sessions. These findings support the suggestion by George et al. [30] that participating in sports teams can ''increase adherence and enhance motivation'' in men. Furthermore, contrary to evidence suggesting that pedometers can increase motivation [82], several (although not all) of the programs that provided participants with pedometers were unsuccessful in increasing physical activity among men, mirroring George et al.'s [30] findings. It may be that a focus on strength-building in combination with vigorous activity to increase overall fitness may be more appealing to men in the sense that it is more aligned with masculine ideals related to health and exercise.
Several of the programs included in this review were designed for obese and overweight men and as such not only aimed to increase physical activity but also to enhance healthy eating. Although physical activity was often reported as the drawing card, once in these programs men were responsive to and interested in nutritional information when it was tailored to them. The lessons learnt from these programs are instructive. For example, in the Workplace POWER trial, researchers found that blue collar working men preferred very specific food-based guidelines such as ''Eat this or don't eat this'' or ''Drink less'' [51,83] and responded favourably to humor that protected masculine connections with food (e.g., ''you don't have to eat like a rabbit'') [51,84]. Thus, male-specific advice and information appears to be an effective strategy for engaging men in weight loss and provides additional support for taking into account gender-related factors in designing programs to support men's healthy living. These strategies suggest the potential for engaging men in a wide variety of health promoting behaviors beyond physical activity.
Also evident is that most men's health promotion success stories-both in terms of feasibility and uptake-have been community-based rather than professionally produced programs [81,85]. This trend might relate to men's resistance and reluctance around engagement with professional health care services and/or providers. Yet, rather than continuing to debate that well traversed terrain about why men don't go to the doctor, dividends reside in linking to end-users early on, both as a means to designing mencentred programs but also in regards to sustaining those programs (i.e., train-the-trainer models). After all, many a seemingly popular program has ended due to funding restraints, and the feasibility of health promotion programs increasingly resides with community-based championsmany of whom are unpaid but highly motivated.
Robertson et al. [33] outlined five themes evident in successful and sustainable health promotion work with men: (a) settings that facilitate men's engagement (e.g., workplace or sports clubs); (b) using a gender-sensitive style or approach; (c) listening to and incorporating feedback from men, (d) providing adequate training and ongoing support; and (e) partnering with trusted community groups. In the present review, the programs that were considered to have taken a gender-sensitive approach drew on many of these themes in the design and delivery of their interventions. Overall, 16 of the studies (comprising 12 different programs) in this review explicitly integrated gender to the program design in some way, whereas only three studies in the original George et al. [30] review had a men-centered approach (and none of these were published prior to 2009). It is noteworthy that all 12 of the programs deemed to be gender-sensitive demonstrated either a significant increase in participants' physical activity or other substantive improvements (e.g., weight loss). These programs provide a promising avenue for engaging men and hold the potential for sustainable health promotion in this hard-to-reach population.
Taken together, the findings reveal some optimising practices in the development and delivery of programs to promote changes in physical activity among men. Interventions may be delivered using group, individual or mixed modes (individual and group); there are examples of successful physical activity programs using each of these delivery modes. What is evident, however, is that programs may benefit from a diverse set of delivery platforms. Entry points for engaging men in physical activity were somewhat more diverse in the reviewed studies compared to those reviewed by George et al. [30] which focused mainly on community-based and health care provider referrals. In the present review, in a handful of studies novel strategies were employed, such as engaging male members of football and angling clubs, and engaging fathers to exercise with their kids. Yet aside from these novel strategies, the majority of physical activity programs for men are not accounting for emerging research on ways that men access and engage in health promotion activities. Although maledominated workplaces can provide important sites for men's physical activity programs, employers have traditionally focussed on workers' compensation rather than targeted health promotion programs [86]. Increasing mental illness related absenteeism and presentism compensation might prompt employers to rethink the benefits of providing work-based programs, especially given the connections between physical activity and men's mental health promotion. Even within the trend of employing health promotion consultants to deliver face-to-face and online resources to underserved worker groups, there is great potential for both advancing the work fitness of employees and reducing worker compensation payouts.
Clearly this is a field where continued research efforts are important to guide the development of effective physical activity programs for diverse male groups. Since the effectiveness of interventions may vary among sub-groups of men and be dependent upon the intersection of gender with age, ethnicity, socioeconomic status, and related factors, researchers need to fully document the characteristic features of interventions, implementation processes (including level of engagement and how sustained engagement was achieved), and the demographic profile of participants. Further research on how to engage diverse groups of men in health promotion programs that include physical activity is also needed. In addition to the studies included in this review, there are evaluations currently underway of physical activity programs designed for specific subgroups of men such as the unemployed [87,88]. Other groups that would benefit from tailored physical activity programs are men whose work involves sedentary activity (e.g., truck drivers), those with chronic diseases Physical Activity Interventions for Men 797 including cancer, and indigenous men. International collaborations to evaluate innovative approaches in multiple sites and in a variety of contexts would also advance the field.

Conclusion
There is an increasing need for and interest in health promotion strategies that effectively target men. Physical activity appears to provide an effective way for men to access health promotion and thus warrants further investigation. Innovations in physical activity programs that focus on masculine ideals and gender influences to tailor programs for men may provide useful strategies in promoting other areas of men's health. This new focus on gender offers a platform for continued innovation in men's health promotion.