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Introduction The number of older adults aged 65 years or older is increasing and is estimated to reach 20% of the western world population in 2030 (Villareal et al., 2005). Thus, adults in this age group is currently the most rapidly expanding segment (Christensen et al., 2009). Old age is, however, associated with a decline in physical function and muscle strength, and a number of health challenges including adverse cardiovascular event and development of type 2 diabetes (Abdelhafiz & Sinclair, 2015; Artero et al., 2012; Houterman et al., 2002; Spirduso & Cronin, 2001). A contributing factor in the progression to loss of physical function and age-related disease is physiological decline, such as reductions in muscle mass, accumulation of body fat, dysregulation of blood lipids and insulin resistance. This physiological deterioration with age reduces the quality of life of the elderly since physical independence and the ability to perform activities of daily living declines (Bherer, 2012). A strategy to attenuate or even reverse the physiological decline and loss of physical function with age is regular exercise (Bickel et al., 2011; Booth et al., 2012; Pedersen & Saltin, 2006). Traditionally, health-promoting exercise activities in older adults have consisted of relative low to moderate intensity continuous exercise, e.g. brisk walking or cycling in the range of 50-90% of maximal heart rate (Pedersen & Saltin, 2006; Pedersen & Saltin, 2015). In addition, regular resistance training is often recommended to the aging population in order to stimulate muscle strength and physical function. However, aerobic exercise and resistance training does lead to different physiological adaptations. Thus, cardiorespiratory fitness and endurance capacity is improved after a period of regular aerobic training with the response being dependent of type, intensity and total training volume (Garber et al., 2011), whereas aerobic exercise does not seem to prevent a loss in maximal muscle strength (Marcell et al., 2014). On the other hand, regular resistance training does elevate maximal muscle strength as well as physical function, but have a limited effect on cardiorespiratory fitness (Andersen et al., 2014a; Peterson et al., 2010). Furthermore, traditional aerobic and resistance training is often organized as individual activities with limited social interaction, which may compromise motivation due to a lack of belongingness (Nielsen et al., 2014). In addition, involving in multiple aerobic and resistance exercise sessions weekly to get sufficient health beneficial effects may not be applicable to the aging population (Chodzko-Zajko et al., 2009). Thus, social stimulating and motivating training types with broad-spectrum adaptations important for health important for health and physical function is needed. Introduction to small-sided team sport games The prevalence of team sport ball games such as soccer, floorball and handball is almost worldwide. Soccer, in particular, is very popular and according to the international football association (FIFA) a total of 270 million is estimated to participate in soccer globally. Floorball (also known as innebandy or floorhockey) has gained 12 increased interest in Denmark in recent years (www.dgi.dk/floorball/floorball-danmark). Globally, floorball is played in more than 80 countries with more than 300.000 active players registered not including recreational active players. In Sweden, floorball is the third most played sport activity with more than 120.000 active players and it is estimated that 500.000 plays floorball at a recreational level in schools, workplaces etc. (Tervo & Nordstrom, 2014). However, despite the wide-spread prevalence of floorball and the increasing popularity of this sport, very few studies have examined this sport. Furthermore, those studies examining this sport have focused almost entirely on injuries in highly trained competitive young athletes (Tervo & Nordstrom, 2014). In addition, the physiological adaptations important for health of other small-sided ball games are not known. These small-sided ball games may be self-constructed, i.e. rules and organization of the games have been adjusted to accustom the target group, e.g. older adults. In the present thesis, ‘Cone ball’ and ‘Hula goal’ are within the category of self-constructed small-sided ball games. Taken together, the health and physiological adaptations of regular floorball and self-constructed small-sided ball games remains unknown and it is not known if these types of exercise modalities are feasible in older adults (+65 years). The concept of small-sided floorball or other small-sided ball games (covered in the present thesis) differs in a number of ways from traditional team sport ball games. Firstly, small-sided ball games are characterized of few participants playing on a small area. Thus, only 3-4 participants on each side is used on pitches sized from 5x10 m to 20x40 m. Secondly, small-sided ball games are organized as intervals separated by periods of rest, allowing recovery between the active bouts. Thirdly, the small-sided ball games are played on a recreational level only without any registration to competitive tournaments, referees and official game rules. Instead, the small-sided ball games consist of small informal matches with a limited number of game rules and without any prior requirements to the participant’s experience and technical level with sports. Organizing the ball games in the above described manner may increase participant involvement (e.g. many ball touches and scored goals) through a feeling of flow in training, i.e. a mental state in which a person performing an activity is fully immersed in a feeling of energized focus, full involvement, and enjoyment in the process of the activity (Nielsen et al., 2014). It may also lead to a high intensity in the training, defined by a significant amount of time spend above 90% of maximal heart rate and number of intense actions, e.g. sprints, accelerations and rapid turns (Bangsbo et al., 2015). Small-sided ball games and physiological adaptations important for health: Brief overview Over the past ten years, the physiological response and health benefits of small-sided recreational soccer have been investigated. The organization of small-sided soccer training differs from traditional soccer training by smaller pitches, fewer participants per team and with the playing time being divided into intervals separated by periods of rest as described above. The studies show that small-sided football is a motivating training form and provides a number of health benefits for untrained healthy young and old adults, but also patient groups such as 13 type 2 diabetics (Bangsbo et al., 2015). Recently, also small-sided floorball was shown to improve vascular function and cardiorespiratory fitness as well as increase muscle mass with a concomitant reduction in body fat in pre- and post-menopausal women (Nyberg et al., 2014a). A mean heart rate of 80% of maximal heart rate during training and considerable time spend above 90% of maximal heart rate in addition to multiple intense actions such as sprints, accelerations, rapid turns and shots may be the underlying cause to such broad-spectrum adaptations. Thus, organizing exercise as small-sided ball games appears to have potential for creating physiological adaptations and improve physical performance for a variety of study groups, including older adults (Randers et al., 2010). However, further research is needed to increase the understanding of the healthpromoting effects of exercise training organized as small-sided ball games, in particular related to ball game type and target group. For example, various small-sided ball games may lead to different physiological responses; e.g. soccer mainly involves multiple lower body activities, whereas floorball is also characterized by a number of upper body actions. Moreover, feasibility, motivation and injuries may be a concern with involving untrained older adults with low physical capacity in regular intense training. Thus, there is a need to examine how regular age-adjusted small-sided ball games with a low weekly training volume (32-48 min) affect these outcomes in different groups of untrained older adults. Specifically, the effects of small-sided floorball training on physiological adaptations important for health and physical function in untrained elderly are not known, despite increasing popularity of this sport. Moreover, floorball training and other small-sided ball games have not been examined in older adults with a more advanced age (up to 93 years) and reduced physical capacity. Physiological adaptations with training in older adults The following sections will briefly review the training effects on key physiological adaptations in older adults. The sections will focus on older untrained adults and the effects of aerobic training, e.g. walking or cycling, with an intensity not exceeding the maximal oxygen uptake, and resistance training, defined as any repetitive exercise that composes a muscular load, e.g. weight training, as well as small-sided ball games on physical function, body composition, cardiovascular adaptations, blood lipids, insulin resistance, and immunological markers. Also, the effect of combining exercise training with dietary protein intake on muscle mass will be described in older adults. Effect of training on physical function in older adults Physical inactivity with aging is associated with loss of physical function (Christensen et al., 2006). The decline in physical function with age is related with loss of muscle mass, muscle strength and neuromuscular capacity (Aagaard et al., 2010; Narici & Maffulli, 2010). In general, exercise training is associated with improvements in physical function in older untrained adults, with the reported effects depending on type, training volume and intensity (Cadore et al., 2013; de et al., 2015). Resistance training, in particular, has shown to be effective in 14 improving physical function and muscle strength of older adults (Liu & Latham, 2009). In line with this, it appears that older adults can benefit from high-intensity power training, i.e. resistance exercises using a high muscle contraction velocity. Thus, in one study, 12 weeks of explosive resistance resulted in improvements in rate of force development and maximal muscle strength in the range 18-51% in older untrained adults (Caserotti et al., 2008). Functionality of the training does also seem to play a role in the transferability of the training, suggesting a more effective training when exercise is performed as functional as possible, i.e. using exercises mimicking the desired outcome, e.g. sit-to-stand capacity or walking stairs (Hawley, 2008). A number of studies have found better physical capacity after small-sided ball games in untrained young adults (Bangsbo et al., 2015; Seidelin et al., 2017), but few studies has examined the effect of small-sided ball games on physical function in older adults. In one study a group of healthy untrained older men aged 65-75 years participated in small-sided soccer 45-60 min two-three times a week for 16 weeks, which resulted in significant better sit-tostand and repeated running performance (Andersen et al., 2014a). However, it is not known if other types of small-sided ball games with a marked lower training volume will affect the physical function of older untrained adults. Effect of training on fat mass in older adults Aging is associated with increased fat mass, in particular abdominal fat mass (Atlantis et al., 2008; St-Onge & Gallagher, 2010). Hormonal changes with age, e.g. reduced levels of testosterone in men, may interfere with the ability to regulate body fat (Vermeulen et al., 1999). Loss of muscle mass in the older adults also reduces resting metabolic rate, since total skeletal muscle mass is the most metabolic demanding tissue in the body (Muller & Geisler, 2016), adding to lower energy expenditure and risk of developing excess body fat storage. Loss of body fat after a period of exercise has been examined by a number of studies. Type of exercise seem to play a role, since aerobic training appear to be more effective in lowering body fat compared to resistance training (Willis et al., 2012). A period of small-sided soccer has also shown to reduce body fat in untrained young adults (Bangsbo et al., 2015), whereas neither 16 nor 52 weeks of small-sided soccer resulted in significant changes in body fat in older untrained adults (Andersen et al., 2016). Thus, the effect of regular small-sided ball games on fat mass remains unclear in older adults. Total training volume, or more preciously, total energy expenditure may be important in terms of fat loss, since body fat regulation is considered to be closely coupled to overall energy intake and expenditure. On the other hand, high training volumes has been associated with no further loss of fat compared to lower training volumes, which appear to be related to a higher energy intake when engaged in high-volume training interventions (Rosenkilde et al., 2012). Another area of interest is loss of abdominal or visceral fat after exercise training, because abdominal fat in particular is associated with increased risk of cardiovascular disease (Booth et al., 2014). It has been suggested that high-intensity exercise is more efficient than low-moderate intensity exercise to induce loss in abdominal fat (Vissers et al., 2013). In the study by Andersen et al. (2016), no significant changes in abdominal fat was observed despite a high intensity in the 15 soccer training, and the effect of regular small-sided ball games on abdominal fat mass, therefore, remains unclear in older adults. Effect of training on muscle mass in older adults Aging is associated with loss of muscle mass, commonly referred to as sarcopenia (Sayer et al., 2008). Thus, muscle mass declines by 3-8% from the age of 30 years, and this rate of decline is even higher after the age of 60 years (Volpi et al., 2004). The loss of muscle mass with age is multifactorial and is associated with loss of motor neurons and reduced physical activity (Aagaard et al., 2010; Burton & Sumukadas, 2010). Several studies have shown that regular resistance training can increase muscle mass in older adults, although this is not a consistent finding (Andersen et al., 2016; Welle et al., 1995). The discrepancy in the anabolic response to resistance training may be due to differences in dietary protein intake (described in further detail in later section), which is known to influence protein synthesis and degradation (Deutz et al., 2014). Thus, aging muscle seem to respond to resistance training (Fiatarone et al., 1990) and it appears that resistance exercise is as effective in older adults as it is in young adults to reverse muscle loss and low muscle protein synthesis (Balagopal et al., 2001). Aerobic training also stimulates muscle protein synthesis (Sheffield-Moore et al., 2004), but is typically not associated with significant muscle hypertrophy. Some studies using intense aerobic training have though demonstrated some degree of muscle hypertrophy, indicating that intensity in training is important for gain in muscle mass in older adults (Coggan et al., 1992). The majority of studies examining small-sided ball games’ effect on muscle mass have used soccer as an intervention with ambiguous findings. Thus, increases in muscle mass have been shown after a period of small-sided soccer in untrained young adults (Krustrup et al., 2010), whereas muscle mass was unaltered after 16 and 52 weeks of regular small-sided soccer training in older untrained adults aged 65-75 years (Andersen et al., 2016). In prostate cancer patients, 12 weeks of small-sided soccer resulted in a small, but significant, increase in muscle mass despite that these subjects were undergoing androgen deprivation therapy (Uth et al., 2014). Thus, the anabolic effect of regular smallsided soccer games is not clear in older untrained adults. Furthermore, the anabolic effect of other small-sided ball games, e.g. floorball training, is not known in older adults. Effect of training on cardiovascular adaptations in older adults Age-related changes in physiological function include reduced pulmonary maximal oxygen uptake, which seem to be related to both a drop in total muscle mass as well as a lower maximal heart rate leading to a lower maximal cardiac output (Hawkins & Wiswell, 2003; Lakatta, 1990). In addition, aging is associated with increased systolic blood pressure at rest (Pinto, 2007), whereas heart rate at rest does not seem to be affected by age (Kostis et al., 1982). The effect of different types of exercise training on cardiovascular adaptations, including blood pressure and heart rate at rest as well as maximal pulmonary oxygen uptake has been examined 16 in a number of studies. According to a meta-analysis including 93 randomized trials, regular aerobic exercise and resistance training with a duration longer than 4 weeks reduces systolic blood pressure at rest in the range 1.8-3.5 mmHg in older adults, and this effect is larger when baseline blood pressure is high, i.e. in hypertensive subjects (8.3 mmHg) (Cornelissen & Smart, 2013). Also, aerobic training is typically associated with a drop in resting heart rate at rest in older adults, probably reflection alterations in the autonomic nervous system (Carter et al., 2003). Older untrained adults do also seem to respond with increases in maximal pulmonary oxygen uptake after a period of aerobic training (Coudert & Van, 2000). In contrast to aerobic training, resistance training is typically not associated with increases in maximal pulmonary oxygen uptake in older adults (Andersen et al., 2014b), unless the subjects initial maximal oxygen uptake is relatively low before initiating the resistance training (Ozaki et al. 2013). The vast majority of studies examining small-sided ball games have focused on soccer. These studies show that regular small-sided soccer training is effective in increasing maximal pulmonary oxygen uptake in young and older adults (Bangsbo et al., 2015; Milanovic et al., 2015). Thus, 16 weeks of soccer training resulted in a 15% increase in maximal oxygen uptake in older untrained adults (Andersen et al., 2014c). Studies examining soccer and other small-sided ball games have also found reductions in blood pressure and heart rate at rest in young and middle-aged adults (Bangsbo et al., 2015; Nyberg et al., 2014b), showing that small-sided ball games can have positive effect on blood pressure and heart rate regulation. However, some questions still need to be answered in order to get a better understanding of the small-sided ball games’ effect on cardiovascular adaptations, including the effect of training volume, type of ball game, and significance of age and physical capacity. Effect of training on blood lipids in older adults The association between blood lipids and age is somewhat uncertain. Some studies have reported increased levels of triglycerides and total cholesterol until the age of 50 years after which the levels stagnated or was lowered, whereas other studies have suggested that levels of blood lipids such as triglycerides and low-density lipoprotein (LDL) cholesterol are unaltered in women, but lowered with increasing age in men (Ferrara et al., 1997). However, these associations are based on cross-sectional studies and statistical analyzes do not suggest that these changes in blood lipids are dependent of age (Ferrara et al., 1997). Thus, a report that have summarized available studies points towards less than optimal lipid and lipoprotein levels in aged individuals (2001). The effect of regular aerobic exercise on blood lipids is notable, in particular on high-density lipoprotein (HDL) cholesterol and triglycerides. Thus, weekly training volumes corresponding to 24-32 km of brisk walking or jogging have been associated with significant increases in HDL cholesterol and reductions in triglycerides in adults (Durstine et al., 2001). On the other hand, reductions in LDL cholesterol are more rarely reported after a period of regular aerobic exercise, unless the training intervention is associated with a drop in body weight (Durstine et al., 2002). In older adults, the effect of randomized controlled trials dealing with the effect of regular exercise on blood lipids has led to conflicting results. A meta-analysis of these studies did 17 though suggest that regular exercise led to increased HDL cholesterol in older adults, whereas reductions in LDL cholesterol and triglycerides did not reach statistical significance (Kelley et al., 2005). In older adults, studies examining the effect of resistance training on blood lipids are scarce, but results from randomized controlled trials indicate that resistance training may have a positive influence on levels of blood lipids (Fahlman et al., 2002; Hagerman et al., 2000). Neither 16 nor 52 weeks of small-sided soccer training did change blood lipid levels in older adults (Andersen et al., 2016), whereas reductions in LDL-cholesterol have been reported after a period of small-sided soccer in young adults (Bangsbo et al. 2015). Thus, taken together, the effect of small-sided ball games in older adults is unclear, with studies in younger adults indicating a potential to alter blood lipids. Effect of training on insulin resistance in older adults Insulin resistance is a reduction in the rate of glucose disposal elicited by a given insulin concentration. Insulin resistance is present in people with type 2 diabetes, but may also develop with aging. The underlying mechanism for insulin resistance is multifactorial, including several hormonal and regulatory factors as well as fatty acid and carbohydrate metabolism (Ryan, 2000). In addition, insulin resistance has been associated with excess body fat, in particular abdominal and visceral fat mass (Ryan 2000). Aerobic training has shown to reduce insulin resistance in aged individuals, and resistance training appears to reduce insulin resistance to the same extent as seen with aerobic training (Lin et al., 2015; Ryan, 2000). Intensity of training seems to play a role for adaptations in insulin resistance. Thus, when controlled for energy expenditure, moderate intensity aerobic training appear to improve insulin resistance more than vigorous high-intensity aerobic training, which may be related to higher fatty acid metabolism at moderate intensities (McGarrah et al., 2016). On the other hand, studies examining maximal-effort short-term interval training, e.g. repeated bouts of 30 s, have reported substantial improvements in insulin resistance, indicating that intensities exceeding the aerobic maximal may be effective in improving insulin resistance (Babraj et al., 2009; Richards et al., 2010). The improved insulin handling after a period of regular exercise seem to be caused partly by reductions in body fat, in particular abdominal and visceral fat mass, but also changes in skeletal muscle, blood flow and insulin signaling (Ryan 2000). Only few studies have examined glucose and insulin levels after a period of small-sided ball games in older adults. One study examined soccer training combined with dietary counseling for 12 weeks in type 2 diabetic patients and found a significant improvement in insulin resistance, which was not observed in the group only receiving diet intervention (de Sousa et al., 2014). In addition, regular small-sided soccer training was also demonstrated to improve glucose control in type 2 diabetic patients, which was associated with lower fat mass and a tendency towards higher levels of glucose transporters in skeletal muscle (GLUT4) (Andersen et al., 2014d). In healthy older adults, regular small-sided soccer training appear to positively influence glucose and insulin control, demonstrated by a significant lower areal under the curve (AUC) in an oral glucose tolerance test (OGTT) as well as a non-significant 27% reduction in plasma insulin levels after 16 weeks of soccer 18 training (Andersen et al., 2016). Thus, regular soccer training appears to have beneficial effects on insulin resistance, in particular in patients that are insulin resistant, i.e. diabetic. However, the effect of other smallsided ball games training in older non-diabetic adults need to be further investigated in order to better understand this type of exercise on insulin resistance. Effect of training on immunological markers in older adults Aging is associated with low-grade chronic systemic inflammation, also referred to as ‘inflammaging’ (Baylis et al., 2013). During a normal-state physiological condition, inflammation responds acutely to external threads such as virus or other hostile bacteria. Low-grade chronic inflammation is, in contrast, a physiological state in which immunological markers, e.g. C-reactive protein (CRP) or interleukin 6 (IL-6), are chronically increased 2-4 fold above normal levels (Bruunsgaard & Pedersen, 2003). Low-grade chronic inflammation has been associated with increased body fat, in particular abdominal fat, and low levels of physical activity (Woods et al., 2012). In recent years, the focus on the anti-inflammatory effects of regular exercise has increased (Astrom et al., 2010; Petersen & Pedersen, 2005). However, equivocal findings have been reported in studies examining regular exercise and low-grade chronic inflammation. Thus, there is a close association between low levels of physical activity and increased markers of inflammation, e.g. CRP in older adults (Bruunsgaard & Pedersen, 2003; Taaffe et al., 2000). On the other hand, the findings of controlled randomized trials are contradictory, where some studies do show reduced levels of immunological markers after a period of regular exercise (Dekker et al., 2007; Mattusch et al., 2000; Tisi et al., 1997), and some do not (Beavers et al., 2010b; Campbell et al., 2008; Dekker et al., 2007). The effect of resistance training on inflammatory markers in older adults has been less studied, with the majority of results being negative, i.e. no changes in levels of inflammatory markers after a period of resistance training (Beavers et al., 2010a). The effect of small-sided ball games on inflammatory markers is largely unknown, in particular in studies examining older adults. One study found reductions in CRP and IL-6 after 8 weeks of small-sided games in middle-aged men (Mendham et al., 2014), and one study found lower levels of vascular markers of inflammation after 12 weeks of small-sided floorball training in pre- and postmenopausal women (Nyberg et al., 2014a). Thus, there are indications that regular small-sided ball games may have an anti-inflammatory effect, but this need to be further examined in older adults. Effect of combined protein intake and training on muscle mass in older adults Aging is associated with a decline in muscle mass (Narici & Maffulli, 2010) and longitudinal studies have shown that from the age of 75 years the annual decline in muscle mass is around 0.7% and 0.9% in women and men, respectively (Mitchell et al., 2012). An inability of older adults to gain muscle mass after an anabolic stimulus, e.g. exercise or intake of dietary protein, may be due to 'anabolic resistance', which is characterized by an impaired ability to increase muscle mass because of a limited ability to utilize protein after an anabolic 19 stimulus (Dickinson et al., 2013; Haran et al., 2012). In older adults it has been found that the protein requirements are not increased above normal dietary intake as the myofibrillar protein synthesis was found to be similar in a resistance exercised leg 23 h post-exercise whether high-protein (28% of total energy intake) or isocaloric low-protein meals (7% of total energy intake) were ingested (Welle & Thornton, 1998). Therefore, when fulfilling the daily protein recommendations for elderly (~0.8-1.2 g/kg), timing of protein intake, i.e. ingesting protein immediately after exercise, may be more important than total protein intake and may cause gain in muscle mass (Cermak et al., 2012). A considerable number of studies have investigated the effect of resistance training with protein supplementation on measures of muscle mass in older adults, whereas the amount of studies examining protein supplementation combined with aerobic training is sparse. The effect of protein supplementation combined with regular resistance training in older adults is not fully understood. Thus, systematic reviews have presented diverse conclusions ranging from increases in muscle mass (Cermak et al., 2012) to inconclusive results (Finger et al., 2015) and no effect (Thomas et al., 2016) after a period of regular resistance training combined with protein supplementation. The heterogeneous findings of protein supplementation on muscle mass in older adults undergoing resistance training is probably influenced by a number of factors, including type, amount and timing of dietary protein as well as type, intensity, and volume of the resistance training. The majority of studies do though recommend that older adults combine resistance training with dietary protein intake in order to increase skeletal muscle mass (Deutz et al., 2014). It has also been discussed if timing of protein is important when total protein intake is adequate since a meta-analysis have shown that total protein intake was the strongest predictor for muscle hypertrophy after controlling for a number of co-variates including gender, protein match between groups, age, body mass and study duration (Schoenfeld et al., 2013), questioning the common held belief that intake of dietary protein in and around training sessions is critical for muscular adaptations (Candow & Chilibeck, 2008). Taken together, in terms of muscle mass hypertrophy, there does seem to be support for combining regular resistance training with dietary protein intake in adults, but the evidence is not solid and more information regarding type, amount and timing of resistance training and dietary protein is lacking in older adults. The effect of small-sided ball games followed by protein supplementation in older adults has not been examined. In young untrained adults, muscle mass has been shown to increase with two weekly sessions of small-sided soccer games for 12 weeks in which the participants’ protein intake was not registered (Krustrup et al., 2009), whereas muscle mass was unaltered after 4 and 12 months of soccer training in untrained men aged 65-75 years despite a large daily intake of protein ~1.7 g/kg (Andersen et al., 2016). It is possible that protein supplementation immediately after small-sided ball games may aid muscle mass gains in older adults, but this need to be examined. Overall aim The overall aims of the present thesis were to examine physiological adaptations important for health after a period of small-sided ball game training and protein ingestion in untrained elderly (+65 years), and to 20 investigate if small-sided ball game training is feasible and can be considered as a health promoting activity for untrained elderly. Key research questions 1) What is the effect of small-sided ball game training on physical function and physiological adaptations important for health in untrained older adults aged +65 years varying in age and physical function (I, III)? 2) What is the effect of protein ingestion after small-sided ball games on muscle mass in untrained elderly (II)? 3) Is it feasible, safe and motivating to conduct small-sided ball games as a health promoting activity for untrained elderly (+65 years) with no previous experience with this type of training and with various age and physical function (I, II, III)? 21