We have recently shown that yearlong regular participation in dancing is associated with an overall superior performance in the elderly, which included cognitive, motor, and sensory functions (Kattenstroth et al., 2010
), thereby covering domains that are not directly related to dancing, such as cognition and sensory functions. This study indicated that dancing might be an ideal option for intervention in age-related degradations. However, the possibility remained that the beneficial effects observed in elderly dancers is due to the fact that a subpopulation of individuals characterized by unusually high fitness levels had chosen an active lifestyle during early adulthood that possibly included dancing, and these individuals were therefore able to maintain such a lifestyle over many years. Accordingly, observational studies alone cannot establish a causal link between dancing and superior performance. To provide direct evidence for a beneficial role of dancing in ameliorating age-related performance decline in elderly individuals, we investigated the effect of a 6-month long professional senior dance class with a workload of 1 h per week in a pre-post design study on a group of neurologically healthy elderly subjects (IG). This group, which had no record of regular dancing or sporting activities within at least the last 5 years, was compared to a matched CG lacking any intervention over the same period. Our present study corroborates our previous findings that dancing has positive effects not only on dance-related parameters such as posture and balance but generalizes on cognitive and sensory functions (Kattenstroth et al., 2010
). Accordingly, regarding a possible predisposition responsible for superior performance in long-term dancers (Kattenstroth et al., 2010
) our current findings support the notion that dancing plays a role in the maintenance of perceptual and cognitive abilities even at old age.
Following our hypothesis about the effect of multi-year dancing activities, we expected to see a broad range of beneficial effects (Kattenstroth et al., 2010
). Therefore, we investigated, besides dance-related parameters such as posture and balance, a range of parameters covering sensorimotor and cognitive abilities as well as multiple-choice reaction times, intelligence, individual lifestyle, and subjective well-being. The criteria for selecting a test included a brief time needed to complete the test, as wells as general acceptance and wide distribution among scientific communities. In this sense, a particular test served as a surrogate for a given domain, implying that other tests for this field would have shown similar effects. In addition, to obtain information about alterations in physical fitness, we measured the cardio-respiratory performance by spiroergometry. After the dance intervention, the subjects in the IG group showed improvements in almost all investigated domains such as cognition, reaction times, tactile and motor performance, posture, and lifestyle. No improvements were found after a period of 6 months within subjects in the CG group; instead, the participants showed degradation of performance in many tasks.
Our data on posture and balance parameters corroborated earlier studies showing the beneficial effects of dance on fitness and posture (Hopkins et al., 1990
; Crotts et al., 1996
; Shigematsu et al., 2002
; Kreutz, 2008
; Sofianidis et al., 2009
). Superior posture and balance are directly linked to the requirements imposed by dancing and are therefore expected to improve. After intervention, the subjects in the IG were able to perform larger forward COP displacements in the anterior direction, while backward COP displacements were increased in the lateral direction (cf. Figure ). These data indicate enhanced postural stability since the subjects were able to shift COPs further without taking a step forward or falling.
A similar argument can be made for the finding of faster RTs in the IG, which may be attributable to the requirements for both high levels of attention and fast and well-coordinated motor responses while dancing. Interestingly, reaction times have been identified as a reliable predictor for the risk of falls (Lajoie and Gallagher, 2004
). Our findings are compatible with a critical role of RTs in describing the overall status of elderly individuals, since the IG group showed significantly shorter reaction times than the CG. Therefore, improvements induced by the dance intervention for both the domain of posture and balance and RTs can be regarded as contributing to a reduced risk of falls. Besides increased reaction times, other factors are involved in mediating reductions in postural stability, such as impaired sensory perception, a decline in muscle strength, and impaired proprioceptive abilities (Goble et al., 2009
; Kalisch et al., 2012b
), which are similarly positively influenced by participation in dancing activities.
Dancing also had positive effects on hand/arm functions with IG group subjects showing improved performance in hand-arm steadiness, control precision, and wrist movements. While some aspects of enhanced hand-arm function might be directly related to dancing activity such as increased muscle strength and sensorimotor coordination, other less specific factors such as attention and concentration might also play an important role, particularly for tasks requiring steadiness. No effects on hand/arm performance were observed in the CG.
Despite the fact that tactile/haptic abilities appear rather unrelated to dancing activities, we found enhanced tactile and haptic performance following the dance intervention. Typically, enhanced tactile discrimination abilities such as those found in blind Braille readers have been associated with unusual and extensive use of the fingers to gather fine-scale spatial tactile information (Van Boven et al., 2000
). Similarly, tactile acuity in professional pianists is significantly higher compared to that of non-musicians, which has been attributed to the extreme usage of the fingers during piano playing (Ragert et al., 2004
). We therefore suggest that the enhanced two-point-discrimination performance found in the IG group might reflect non-specific factors that are independent of dancing activities and beyond the framework of use. Interestingly, in a recent study of experienced adult Tai Chi practitioners, superior spatial tactile acuity in comparison to matched controls has been reported (Kerr et al., 2008
). This was explained by assuming that either individuals with high fitness levels are drawn to Tai Chi or Tai Chi itself drives cortical changes that lead to superior tactile acuity. We suggest that the enhanced tactile discrimination performance arises because of exposing individuals to enriched environmental conditions as created through dancing activities; for a discussion of neurotrophins, see below.
The age-related decline in cognitive performance is a major factor negatively affecting life quality (Mayer and Baltes, 1996
; Dinse, 2006
; Mahncke et al., 2006
; Persson and Nyberg, 2006
). Therefore, many attempts have been made at utilizing training strategies to delay and ameliorate cognitive decline. Here, we found a widespread improvement of cognition and attention, as assessed by RBANS after the dance intervention, while no differences were found in the CG group. Major improvements were found for RBANS subtests “list learning
,” “figure copy
,” and “list recall
.” Additionally, in the IG group, significant improvements were found in performance on the non-verbal learning test for high associative geometric items. It had been suggested that learning new dance steps requires three-dimensional and geometric thinking, which has been associated with improved learning capabilities.
Given that dancing is a primarily physical activity, these findings are consistent with recent studies demonstrating that in healthy elderly individuals there is a close association between physical fitness and cognitive performance (Sumic et al., 2007
). Consequently, many studies in the elderly have shown that improving aerobic capacities through physical exercise programs has beneficial effects on cognitive performance (Kramer et al., 1999
; Deley et al., 2007
; Sumic et al., 2007
; Hillman et al., 2008
) and that physical activity can even reduce the likelihood of developing cognitive impairments (Kramer et al., 2006
; Thurm et al., 2011
In contrast, no changes were found for a marker of non-verbal fluid intelligence in either intervention or CGs. Unlike crystallized intelligence, fluid intelligence is rather resistant to intervention unless through explicit training (Bors and Vigneau, 2003
; Jaeggi et al., 2008
). Interestingly, there seems to be a high correlation between intelligence and working memory tasks (Conway et al., 2003
). A classic working memory task included in the RBANS is the digit repetition test. In line with our findings on intelligence, we found no improvements in this RBANS subtest for either group. However, considering that the possible improvements in fluid intelligence are dosage-dependent (Jaeggi et al., 2008
), further investigations would be needed to disentangle the effect of other dancing intensities on working memory and fluid intelligence by addressing the question of whether higher intensities or longer periods of dancing intervention would also produce effects on non-verbal fluid intelligence.
Animal research has suggested that use-dependent plasticity, synaptic efficacy, and the maintenance of synaptic connections are controlled and modulated by neurotrophins, such as brain-derived neurotrophic factor (BDNF). BDNF levels are increased by many factors, including physical activity and social interaction (Neeper et al., 1995
; Churchill et al., 2002
; Kramer et al., 2006
; Vaynman and Gomez-Pinilla, 2006
). In contrast, stress and depression have been extensively documented to produce widespread CNS reductions of neurotrohpin expression followed by atrophy, degeneration and loss of excitatory neurotransmitter release in animal models (Stone et al., 2008
). However, in order to provide an explanation for the improvements in domains unrelated to dancing, we suggest a critical role of the neurotrophic factors. Housing animals under enriched environmental conditions have shown increased neurotrophin gene expression, which thus exert neuroprotective effects (Young et al., 1999
; Mattson et al., 2004
). Generally, mild stress responses in cells have been implicated as a major driving factor in up-regulating stress resistance genes and growth factors (Mattson, 2008
). Interestingly, the factors inducing mild stress are sensory stimulation, physical activity, and cognitive challenges—all of which are involved in dancing.
It has recently been shown in humans that dancing elicits activity in multiple brain regions (Brown et al., 2006
). It was observed that the learning of new and complex dance-related movements entailed changes in both functional and effective connectivity in unfamiliar dance situations.
Maximal oxygen consumption or aerobic power is known to peak around the age of 25 and declines progressively thereafter (Astrand et al., 1973
; Zoeller, 2008
) with an accelerated rate of decline after the age of 60 (Fleg et al., 2005
). However, it is well documented that aerobic exercise interventions, designed to improve cardio-respiratory fitness, improve cardio-respiratory performance as assessed by VO2peak
in elderly individuals (Colcombe et al., 2004
; Kramer et al., 2006
; Hillman et al., 2008
; Erickson and Kramer, 2009
). However, most of these studies used a vigorous intervention with high intensity levels of 40–50% to 60–70% of the peak heart rate for 45 min per week for 6 months (Colcombe et al., 2004
), 3 sessions of 40 min at 50–85% VO2max
for 26 weeks (Hagberg et al., 1989
), or 50–85% of peak heart rate in 5 sessions of 45 min per week for 6-months (Stratton et al., 1994
). In our present study, we found no differences in the cardio-respiratory performance over the 6-month study period in either group. These findings are remarkable since they indicate that the substantial beneficial effects of the dance intervention were largely unrelated to changes in cardiovascular fitness. Typically, improved cardio-respiratory performance is associated with improved performance in both general fitness and cognitive and executive abilities (Colcombe et al., 2004
; Kramer et al., 2006
; Sumic et al., 2007
; Hillman et al., 2008
). In contrast, we found improvements in cognitive and sensorimotor performance as well as improvements in reaction times and postural performance in the absence of cardio-respiratory improvements. A possible reason for this might be the relatively short intervention time of 1 h per week. More importantly, the dance intervention applied here, which follows the so-called Agilando™ program, can be characterized by a discontinuous kind of physical exercise, where the dancing activity is interrupted for one or 2 min whenever a new sequence of dance steps is started. Conceivably, this allows the participants to recover during the dance course thereby preventing to drive lasting changes in VO2peak
. Our findings therefore suggest that even activities requiring moderate doses of cardio-respiratory fitness are capable of driving remarkable behavioral and cognitive improvements in elderly participants.
In this context, it is noteworthy that in addition to the aspects of physical exercise and the requirements for fine motor coordination, posture and balance - the emotional aspects of dancing and its close association with music - might add further beneficial effects. Studies in children have demonstrated that intensive music training was associated with improved performance in the core mathematical system for representing abstract geometry, indicating a fundamental association between musical and mathematical cognition (Spelke, 2008
). More generally, it is undisputed that musical stimulation has measurable effects on behavior and brain chemistry (Panksepp and Bernatzky, 2002
). For example, music-exposed mice showed increased BDNF levels in the hippocampus (Angelucci et al., 2007
). Similarly, learning to dance by effective observation appeared to be closely related to learning by physical practice, both in the level of achievement and the neural substrates that support the organization of complex actions (Cross et al., 2009
). Conceivably, other cognitive skills might benefit from the effective observational learning typically associated with dancing.
The impact of such emotional factors is reflected by the changes in subjective well-being and contentment in life (cf. Table ); 76% of the subjects in the IG group reported that they felt much better and more vital in general. With regard to the musculoskeletal system, 52% reported experiencing less pain, while 100% reported having a good feeling about doing something for themselves; 96% would recommend such an intervention to other people and 76% would like to continue. Our data show that after the dancing class, the subjective well-being and contentment in life improves, which is consistent with previous findings on dance in connection with cultural activities, music, singing, social interaction, health, and lifestyle (Hui et al., 2008
; Kreutz, 2008
; Hackney and Earhart, 2010
). Since this is widely beyond the scope of the present article, we will address this topic extensively in another manuscript that is currently prepared for publication.
The analyses of the indices of performance (IP), which were calculated to allow direct comparison of performance across all individual tests, provided some insight into the question of how the dance intervention acted at an individual level. In a previous study conducted with a group of older amateur dancers, we showed that the best performers in each task were present in both the dancing and the CGs with similar frequency, but that the amateur dancing group lacked the number of poor performers that were frequently found within the CG (Kattenstroth et al., 2010
). In another study of a group of older expert dancers, we showed that for non expertise-related domains such as tactile abilities, poor performers were equally present in both the expert dancer group and CG but that in the expert-related domains again, poor performers were rare in the expert dancer group as compared to controls (Kattenstroth et al., 2011
). Here, we show that the number of subjects characterized by an IP > 0.5 in 4 out of 6 domains in the IG group significantly increased after intervention. Importantly, these improvements were found both in domains directly related to dancing activities such as reaction times but also in unrelated domains such as tactile ability. In contrast, no differences in the IP distribution were found for subjects in the CG group.
Our findings correlating baseline performance with improvement following intervention provide further evidence that those individuals who benefitted most from the intervention were those who showed the lowest performance levels prior to the intervention. This observation is of particular interest when dance is used as an intervention in impaired subpopulations. Conceivably, the overall small beneficial effects of dancing on individuals characterized by an overall high-level performance can be interpreted as a ceiling effect limiting further improvement. On the other hand, it remains to be investigated whether a more intensive and/or longer intervention would have affected the very good performers in a similar way.
Compared to activities such as exercising, walking or playing an instrument, dance has the advantage of combining several key features, each well-documented to have beneficial effects: dancing activities include physical exercise, but can be performed at different levels of expertise, resulting in a high compliance and motivation, with only a few dropouts. Furthermore, dancing activities include social and emotional interactions as well as cognitive requirements. Moreover, our present data show that even moderate doses of physical activity, which are not sufficient to affect cardio-respiratory performance, can in combination with these other features have beneficial effects on cognition, attention, posture and balance, and sensorimotor performance, as well as subjective well-being. Given these findings, dancing activities seem to be a highly appropriate choice of intervention to ameliorate age-related deterioration by enforcing and maintaining plasticity processes, thereby contributing to successful aging.
Conflict of interest statement
One Author (Jan–Christoph Kattenstroth) is a recipient of a stipend from the Allgemeiner Deutscher Tanzlehrerverband (ADTV). The other authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.