This study evaluated health benefits of a supported physical activity program for 116 older carers (mean age 64.4 [SD = 7.9], 85% women). Participants undertook a 6-month center-based physical activity program (strength training, yoga, or Tai Chi). Eighty-eight participants (76%) completed the program. Multivariate repeated-measures ANOVA identified overall significant improvement postint-ervention (p = .004). Univariate analyses revealed significant improvements for balance, strength, gait endurance, depression, and SF-36 (physical component; p < .05). There was no change in the Zarit Carer Burden Scale (p > .05). Change in performance scores did not differ significantly between those with higher and lower attendance at classes, although there was significantly greater improvement in gait endurance and balance (p < .05) in those attending classes run twice weekly than in those attending once-weekly classes. In conclusion, a carer physical activity program, providing additional carer support to facilitate participation, can achieve high levels of involvement by carers and significant health benefits.
Keith Hill, Robyn Smith, Marcia Fearn, Mary Rydberg and Rachael Oliphant
Jin H. Yan and John H. Downing
Tai Chi, an ancieni form of Chinese fitness exercise, affords its participants a variety of physical and psychological benefits. Research has suggested that individuals engaging in Tai Chi exercises improve cardiovascular fitness and motor control while reducing stress, anxiety and depression. Tai Chi is particularly suitable for seniors, who are often at risk for a variety of problems associated with aging (e.g.. arthritis, neurological dysfunction, and general decline of balance, coordination, and locomotor function). Because of its self-paced. nonstressful, and noncompetitive nature, and its ability to afford economy of lime, space, and equipment, Tai Chi presents an effective, functional alternative exercise form for the senior adult population. This article presents the background of Tai Chi practice and introduces several key elements and suggestions for teaching Tai Chi to senior participants. Finally, some selected resources for Tai Chi practice are listed.
This experiment examined, through quantitative measures, exercise dependence in subjects who had been running at least a year and ran at least 5 days a week. The subjects, 24 males and 9 females, were randomly assigned to groups according to the Solomon four-group design. Two groups ran and the other two did not on the day of the experiment. Pretests were given to one of the running and one of the nonrunning groups. Dependent variables were the Profile of Mood States (POMS) and galvanic skin response. Overall multivariate analysis showed a significant running by pretest interaction. The nonpretested running group revealed significantly lower depression (POMS) and GSR scores than the nonpretested nonrunning group. The results suggest that even slight variations from running schedules may have a negative effect on habitual runners.
Dori E. Rosenberg, Jacqueline Kerr, James F. Sallis, Gregory J. Norman, Karen Calfas and Kevin Patrick
The authors tested the feasibility and acceptability, and explored the outcomes, of 2 walking interventions based on ecological models among older adults living in retirement communities. An enhanced intervention (EI) was compared with a standard walking intervention (SI) among residents in 4 retirement facilities (N = 87 at baseline; mean age = 84.1 yr). All participants received a walking intervention including pedometers, printed materials, and biweekly group sessions. EI participants also received phone counseling and environmental-awareness components. Measures included pedometer step counts, activities of daily living, environment-related variables, physical function, depression, cognitive function, satisfaction, and adherence. Results indicated improvements among the total sample for step counts, neighborhood barriers, cognitive function, and satisfaction with walking opportunities. Satisfaction and adherence were high. Both walking interventions were feasible to implement among facility-dwelling older adults. Future studies can build on this multilevel approach.
Elissa Burton, Gill Lewin and Duncan Boldy
The 3 study objectives were to compare the activity levels of older people who had received a restorative home care service with those of people who had received “usual” home care, explore the predictors of physical activity in these 2 groups, and determine whether either group met the minimum recommended activity levels for their age group. A questionnaire was posted to 1,490 clients who had been referred for a home care service between 2006 and 2009. Older people who had received a restorative care service were more active than those who had received usual care (p = .049), but service group did not predict activity levels when other variables were adjusted for in a multiple regression. Younger individuals who were in better physical condition, with good mobility and no diagnosis of depression, were more likely to be active. Investigation of alternatives to the current exercise component of the restorative program is needed.
Eric J. Sprigings and Doris I. Miller
Optimized computer simulation, using a mathematical model of a diver, was employed to gain insight into the primary mechanical factors responsible for producing height and rotation in dives from the reverse group. The performance variable optimized was the total angular displacement of the diver as measured from last contact to the point where the diver's mass center passed the level of the springboard or platform. The times of onset, and lengths of activation for the joint torque actuators, were used as the control variables for the optimization process. The results of the platform simulation indicated that the magnitude of the hip torque was approximately twice that generated by the knee joint during the early extension phase of the takeoff. Most of the knee extension for the simulation model coincided with the period of reduced hip torque during the later phase of takeoff, suggesting that the knee torque served mainly to stabilize the lower limbs so that the force from the powerful hip extension could be delivered through to the platform. Maintaining a forward tilt of the lower legs (~50° from the horizontal) during hip and knee extension appeared to be paramount for successful reverse somersaults. Although the movement pattern exhibited by the springboard model was limited by the torque activation strategy employed, the results provided insight into the timing of knee extension. Peak knee extension torque was generated just prior to maximum springboard depression, allowing the diver's muscular efforts to be exerted against a stiffer board. It was also apparent that the diver must maintain an anatomically strong knee position (~140°) at maximum depression to resist the large upward force being exerted by the springboard against the diver's feet. The optimization process suggested that, as the number of reverse somersaults increases, both the angle of the lower legs with respect to the springboard and the angle of knee extension at completion of takeoff should decrease.
Paul D. Loprinzi
High family functioning is associated with reduced depression symptoms, better academic achievement, less disordered eating, and better metabolic control among youth. However, we know very little about the role of family functioning on physical activity and sedentary behavior among youth, which was the purpose of this study.
Data from the 2003 and 2011–2012 cycles of the National Survey of Children’s Health were used. A total of 61,226 parents/guardians from the 2003 cycle and 40,446 parents/guardians from the 2011–2012 cycle (total n = 101,672) across all 50 states and the District of Columbia were examined. Parents answered questions related to family functioning and their child’s (age 6–17 yrs) physical activity and sedentary behavior.
Results were the same across both cycles; after adjustments, youth engaged in less physical activity if the family had worse family functioning (β = −0.06, P < .001). Similarly, youth engaged in more sedentary behavior if the family had worse family functioning (β = 0.05, P < .001).
This research suggests that youth are more active and engage in less sedentary behavior if their family has greater family functioning.
Michael J. Grey, Charles W. Pierce, Theodore E. Milner and Thomas Sinkjaer
The modulation and strength of the human soleus short latency stretch reflex was investigated by mechanically perturbing the ankle during an unconstrained pedaling task. Eight subjects pedaled at 60 rpm against a preload of 10 Nm. A torque pulse was applied to the crank at various positions during the crank cycle, producing ankle dorsiflexion perturbations of similar trajectory. The stretch reflex was greatest during the power phase of the crank cycle and was decreased to the level of background EMG during recovery. Matched perturbations were induced under static conditions at the same crank angle and background soleus EMG as recorded during the power phase of active pedaling. The magnitude of the stretch reflex during the dynamic condition was not statistically different from that during the static condition throughout the power phase of the movement. The results of this study indicate that the stretch reflex is not depressed during active cycling as has been shown with the H-reflex. This lack of depression may reflect a decreased susceptibility of the stretch reflex to inhibition, possibly originating from presynaptic mechanisms.
Takaaki Mishima, Takashi Yamada, Makoto Sakamoto, Minako Sugiyama, Satoshi Matsunaga, Hirohiko Maemura, Muneshige Shimizu, Yoshihisa Takahata, Fumiki Morimatsu and Masanobu Wada
This study was conducted to determine whether dietary chicken-breast extract (CBEX), a rich source of histidine-containing dipeptides, could modify exerciseinduced changes in sarcoplasmic reticulum (SR) function. After 5 weeks of dietary CBEX, SR Ca2+-handling ability was examined in the vastus lateralis muscles of rats subjected to high-intensity running for 2.5 min. Dietary CBEX caused an approximately 15% and 45% increase (p < .01) in muscle carnosine and anserine concentrations, respectively. In resting muscles, depressions in SR Ca2+–ATPase activity were evoked by dietary CBEX without concomitant changes in SR Ca2+ uptake and release rates. The data confirm that high-intensity exercise depresses SR Ca2+ handling. In spite of the same run time, SR Ca2+ handling was reduced to a lesser degree in muscles of CBEX-containing-chow-fed rats than in standard-chow-fed rats (p < .05). These results suggest that dietary CBEX might attenuate deteriorations in SR Ca2+-handling ability that occur with high-intensity exercise.
Takashi Kato, Yusaku Takeda, Toshio Tsuji and Tatsuya Kasai
The present study investigated the relative contribution of the cortical and spinal mechanisms for post-exercise excitability changes in human motoneurons. Seven healthy right-handed adults with no known neuromuscular disabilities performed an isometric voluntary wrist flexion at submaximum continuous exertion. After the subjects continued muscle contraction until volitional fatigue, the H-reflexes induced by an electric stimulation and motor evoked potentials (MEPs) induced by a transcranial magnetic stimulation (TMS) from a flexor carpi radialis (FCR) muscle were recorded 7 times every 20 s. The H-reflex was used to assess excitability changes at the spinal level, and the MEP was used to study excitability changes at the cortical level. H-reflexes showed a depression (30% of control value) soon after the cessation of wrist flexion and recovered with time thereafter. On the other hand, an early (short latency) MEP showed facilitation immediately after the cessation of wrist flexion (50% of control value) and thereafter decreased. A possible mechanism for the contradictory results of the 2 tests, in spite of focusing on the same motoneuron pool, might be the different test potential sizes between them. In addition, a late (long latency) MEP response appeared with increasing exercise. With regard to the occurrence of late MEP response, a central mechanism may be proposed to explain the origin—that is, neural pathways with a high threshold that do not participate under normal circumstances might respond to an emergency level of muscle exercise, probably reflecting central effects of fatigue.