Phy Edu & Sports Sc Unit

PHY EDU & SPORTS SC UNIT

Researcher : Macfarlane DJ

Project Title:	Establishing valid criteria to assess levels of habitual activity in Hong Kong students
Investigator(s):	Macfarlane DJ
Department:	Institute of Human Performance
Source(s) of Funding:	Small Project Funding
Start Date:	11/2002
Completion Date:	10/2005

Abstract:

To establish uniquely specific criteria using both objective and subjective measurements of free-living habitual physical activity, in order to more accurately classify sedentary, low, moderate, and vigorous levels of activity across a range of Hong Kong male and female students; to simultaneously acquire data from a range of monitoring devices known to reliably measure habitual physical activity (gas analysis, heart ate, accelerometers, pedometers), in order to provide usable data to a wide range of Hong Kong health professionals.

Project Title:	Enhancing elite performance by development of a biofeedback instrumentation system
Investigator(s):	Macfarlane DJ
Department:	Institute of Human Performance
Source(s) of Funding:	Small Project Funding
Start Date:	01/2006

Abstract:

In order for an any athlete to try to maximize his/her performance it is essential that the athlete receives appropriate and meaningful feedback. Often this feedback is based purely on the coach’s subjective assessment of the athlete’s performance during visual observations in training or competition (Shakespear, 1980). Such feedback is temporally limited and relies heavily on both the recall ability of the coach and athlete, although it can be aided by video-recording, which itself has the limitation of being time-consuming and somewhat cumbersome for the coach to operate in an active coaching environment. A more ideal coaching tool is to develop an instrumented data-acquisition system based around an ergometer that accurately simulates the athletic event, which not only incorporates on-line data recording as well as providing instantaneous “biofeedback” to the coach/athlete, but can also provide detailed post-hoc analysis. This type of objective assessment using empirically acquired data has the potential to substantially aid the development of sub-elite athletes as well as to fine-tuning the peak performances of elite athletes, but requires the development of specialist hardware and software. This proposal is to extend the development of an existing data-acquisition system (very early development work funded by a HKU new staff member grant in 1994, which was then substantially revised with new hardware/software using an externally funded grant in 2003). In the sport of rowing it is commonly regarded that the leg-drive phase of the rowing stroke is critical to the development of power since it contributes the largest component towards boat velocity (Lamb, 1989). However, certain issues on the leg-drive still remain unanswered within the international community, with a recent expert review of the area (Soper & Hume, 2004) concluding that future research should focus on “the influence of foot-stretcher positions on rowing performance” and “can coaches or selectors use force application profiles to reliably or validly predict a rowers performance”. These are clearly two key research questions that need to be investigated by the international research community in relation to expert rowing performance. From these critical comments we propose to investigate (i) what is the most ideal position of the feet during this leg-drive phase, and (ii) whether the force applied to the seat (owing to the lifting-action of the leg-drive) would serve as a simple and reliable proxy of an efficient rowing technique (coaches often refer to this as the rowers ability to “hang”). This current proposal is to incorporate the addition of specialist hardware and software to an existing ergometer to allow for detailed investigations on the effects of how the position of the foot-stretcher can influence power development, and to determine if the force applied to the seat was an acceptable proxy for effective leg drive and power development using an instrumented ergometer system designed to provide real-time biofeedback to the coach and athlete.

List of Research Outputs

Researcher : Masters RSW

Project Title:	Enhancing motor skills through instructional manipulations: is the learner paying attention?
Investigator(s):	Masters RSW, Maxwell JP, Raab M.
Department:	Institute of Human Performance
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	02/2004

Abstract:

To conduct a test of the competing theories; to ascertain the validity of external/internal feedback; to establish the process that leads to enhanced performance.

Project Title:	Brief periods of implicit motor learning: Performance advantages or disadvantages?
Investigator(s):	Masters RSW, Jackson C, Maxwell P
Department:	Institute of Human Performance
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	06/2005

Abstract:

A number of advantages have been shown for implicit motor learning (see Masters & Maxwell, 2004 for a recent review). These advantages include robustness under (1) secondary task loading (multi-tasking) (2) psychological stress and (3) potentially, physiological stress. Maxwell, Masters, Kerr, and Weedon (2001) suggested that an effective means by which to cause implicit motor learning is to reduce learning errors. They showed that participants learning to play golf in an errorless condition committed significantly fewer errors throughout learning than those in an errorful condition. Not only was performance superior in retention, but imposition of a secondary cognitive load resulted in performance deterioration for errorful learners but not errorless learners. Paradoxically, verbal recall in both conditions was not different, with participants reporting substantial amounts of task relevant declarative information. Access to task relevant knowledge (or metaknowledge) is not expected in implicit learning. Upon closer inspection of their data, Maxwell et al found that error commission in the errorless condition occurred with considerably greater frequency from putting distances greater than or equal to 1 m. From distances of 25 cm, 50 cm or 75 cm few errors were committed. Maxwell et al speculated that hypothesis testing occurred only after the first 150 trials of learning, as the task became more complex. The build up of declarative knowledge, therefore, would be confined to later trials. In order to examine whether this was the case, a second study was devised in which hypothesis testing behaviour was assessed during 150 trials of learning either from 25, 50, and 75 cm consecutively (errorless learning) or from 175, 150 and 125 cm (errorful learning). Following the learning phase, a transfer task was completed from 100cm, in which working memory was again loaded with a secondary tone counting task. Relative to a separate control group who did not perform the secondary task, the errorful learners exhibited significant performance deterioration; conversely, performance in the errorless condition remained robust, consistent with findings from the previous experiment. Fewer rules associated with hypothesis testing were reported by the errorless group, supporting the idea that errorless learners in the first experiment had accrued declarative knowledge only after completing the first 150 trials. Additionally, video analysis showed that fewer visible adjustments to technique were implemented by the errorless group, supporting the idea that they did not test hypotheses over shorter distances. Maxwell et al concluded that participants in the errorless condition of Experiment 1 learned implicitly during the first 150 trials. This implies that initial implicit acquisition of a motor skill allows later performance to take place with little input from working memory despite subsequent accumulation of declarative knowledge. Work in the cognitive literature by Reber, Kassin, Lewis and Cantor (1980) indicates that explicit introduction of rules underlying an artificial grammar structure is detrimental to learning that has previously occurred implicitly. Matthews, Buss, Stanley, Blanchard-Fields, Cho and Druhan (1989), on the other hand, examined various combinations of implicit and explicit learning in artificial grammar learning and found that a performance enhancing synergistic learning effect occurred when participants initially learnt implicitly then explicitly. Matthews et al argued that the superior learning effect was likely to be a consequence of implicit learning mechanisms facilitating the generation of successful hypotheses during the explicit phase. These contrasting findings have not been addressed directly in the domain of motor learning. The objective of the present study will be to replicate Maxwell et al’s findings by explicitly examining the effect of combining explicit motor learning with previous implicit motor learning.

List of Research Outputs

Researcher : McManus AM

Project Title:	Exercise testing in normal children and children with congenital heart disease
Investigator(s):	McManus AM, Yung TC
Department:	Phy Edu & Sports Sc Unit
Source(s) of Funding:	Children's Heart Foundation - General Award
Start Date:	09/2000

Abstract:

To establish norm values for C-P fitness; to establish normative values for C-V function during exercise in children; to assess the impact of PA and inactivity on C-P / C-V function.

Project Title:	Heart rate monitors as a motivational tool in physical education in Hong Kong
Investigator(s):	McManus AM, Masters RSW
Department:	Institute of Human Performance
Source(s) of Funding:	Polar Electro Qy - General Award
Start Date:	01/2004

Abstract:

The aim of this project is to use heart-rate monitors as a motivational tool to encourage in children the activity they need for a lifetime of health and well being. The first goal will be to establish whether heart-rate monitors, when used in conjunction with an educational heart health programme, i) have an immediate, short-term effect on markers of motivation of children to be active and ii) whether this results in increased physical activity. A second goal will be to establish whether points i) and ii) above are maintained in the long-term and whether this maintenance is dependent on continued use of the heart-rate monitors. A third goal will be to establish whether increased physical activity, if sustained in the long-term, is sufficient to accrue change in health-related outcomes, such as body composition and aerobic fitness.

Project Title:	The role of peroxisome proliferator-activated receptor δ in regulating spontaneous physical activity
Investigator(s):	McManus AM, Leung FCC, Chu YW
Department:	Institute of Human Performance
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	02/2005

Abstract:

The study is designed to address the hypothesis that peroxisome proliferator-activated receptor δ (PPAR-δ) inherently modulates spontaneous physical activity in the up-regulation of lipid catabolism and thermogenesis. Spontaneous non-exercise activity has been found to be an important compensatory mechanism against fat gain in humans who have been over-fed (1), however, how increases in non-exercise activity are regulated is unclear. Levine et al. (1) observed spontaneous movements in adults and evaluated what they termed the non-exercise activity thermogenesis (NEAT). Their work demonstrated that individuals with high levels of NEAT engendered more energy expenditure and had decreased susceptibility to adiposity when compared with those individuals with lower levels, even when both groups were overfed. More recent evidence has demonstrated thyroid hormone plays a role in the alteration of NEAT (2), and tentative molecular pathways underpinning this relationship, including uncoupling proteins, have been suggested. PPAR-δ participates in the up-regulation of energy metabolism (3) and appears to induce pleiotropic responses in skeletal muscle which result in an improved metabolic profile and improved athletic performance (4,5). Peroxisome proliferator-activated receptors have been substantially implicated in relation to growth and obesity since synthetic PPAR-δ agonists revealed PPAR-δ's regulation proficiency on fatty acid oxidation and energy homeostasis (6). Alterations were subsequently detected in adipose tissue after targeted disruption of PPAR-δ in mouse (4). Transgenic over-expression of PPAR-δ in adipose tissue produces obese-resistant mice, even when fed with a high-fat diet. Recent findings showed that PPAR-δ mediated with transcriptional cofactor peroxisome proliferator-activated receptor-gamma co-activator 1α (PGC-1α) can regulate muscle fiber specification. Muscle fiber type I was increased and mitochondrial biogenesis occurred after activation (4). The oxidatively optimised muscle improves endurance capacity, however, whether it results in increases in spontaneous activity is unknown. References 1. Levine JA, Eberhardt NL, Jensen MD. (1999) Role of nonexercise activity thermogenesis in resistance to fat gain in humans. Science, 283: 212-214. 2. Levine JA, Nygren J, Short KR, Sreekumaran Nair K. (2003) Effect of hyperthyroidism on spontaneous physical activity and energy expenditure in rates. Journal of Applied Physiology, 94: 165-170. 3. Wang YX, Lee CH, Tieo S, Yu RT, Ham J, Kang H, Evans RM. (2003) Peroxisome proliferator-activated receptor δ activates fat metabolism to prevent obesity. Cell, 113: 159-170. 4. Luquet S, Lopez-Soriano J, Holst D, Fredenrich A, Melki J, Rassoulzadegan M, Grimaldi PA. (2003) Peroxisome proliferator-activated receptor δ controls muscle development and oxidative capability. The FASEB Journal, 10.1096/fi.03-0269fje. 5. Wang TX, Zhang CL, Yu RT, Cho HK, Nelson MC, Bayuga-Ocampo CR, Ham J, Kang H, Evans RM. (2004) Regulation of muscle fibre type and running endurance by PPARδ. PLOS Biology, 2: e294 6. Peters JM. Lee SS. Li W. Ward JM. Gavrilova O. Everett C. Reitman ML. Hudson LD. Gonzalez FJ. (2000) Growth, adipose, brain, and skin alterations resulting from targeted disruption of the mouse peroxisome proliferator-activated receptor beta(delta). Molecular & Cellular Biology, 20: 5119-28.

List of Research Outputs

Researcher : Mcmanus AM

Project Title:	Exercise testing in normal children and children with congenital heart disease
Investigator(s):	McManus AM, Yung TC
Department:	Phy Edu & Sports Sc Unit
Source(s) of Funding:	Children's Heart Foundation - General Award
Start Date:	09/2000

Abstract:

To establish norm values for C-P fitness; to establish normative values for C-V function during exercise in children; to assess the impact of PA and inactivity on C-P / C-V function.

Project Title:	Heart rate monitors as a motivational tool in physical education in Hong Kong
Investigator(s):	McManus AM, Masters RSW
Department:	Institute of Human Performance
Source(s) of Funding:	Polar Electro Qy - General Award
Start Date:	01/2004

Abstract:

Project Title:	The role of peroxisome proliferator-activated receptor δ in regulating spontaneous physical activity
Investigator(s):	McManus AM, Leung FCC, Chu YW
Department:	Institute of Human Performance
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	02/2005

Abstract:

List of Research Outputs

Researcher : Sit HP

Project Title:	Psychological Reversals of Children’s Game Participatory Behaviour
Investigator(s):	Sit HP, Masters RSW, Kerr H
Department:	Institute of Human Performance
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	06/2006

Abstract:

Children and youth nowadays are being raised in a “cyberworld” where electronic media increasingly shapes their feelings, attitudes and behaviors (Strasburger, 1995). There is widespread concern that electronic media such as television viewing and computer and video game playing contributes to childhood obesity problems. Children and youth on average spend 32 minutes per day playing electronic games (Beentjes, Koolstra, & Marseille, 2001) and the amount of combined video and computer usage exceeds television viewing (Christakis, Ebel, Rivara, & Zimmerman, 2004). There is compelling evidence that the sedentary nature of electronic media is associated with high body fatness and therefore is an important behavioral risk factor for overweight children (Andersen, Crespo, Barlett, Cheskin, & Pratt, 1998; Eisenmann, Bartee & Wang, 2002; Tremblay & Willms, 2003). Other studies, however, report that such an association is weak (Marshall, Biddle, Gorely, Cameron, & Murdey, 2004) and that simply trying to minimize electronic media such as television viewing is not the best intervention strategy to reduce the sedentary behavior of children (Norman, Schmid, Sallis, Calfas, & Patrick, 2005). Numerous researchers have attempted to make use of different physical activity games as effective strategies to develop and encourage children to adopt a more active lifestyle (Kelder et al., 2005). To identify intervention strategies to promote physical activity in children, Finfgeld, Wongvatunyu, Conn, Grando, and Russell (2003) have recently addressed a need to apply Reversal Theory (Apter, 2001, 2005) as a new and emerging approach to understanding human behavior change within the public health field. This theory posits that human personality comprises some relatively fixed personality characteristics or motivational style profiles. These profiles consist of four pairs of motivational states (i.e., telic-paratelic, conformist-negativistic, autic-alloic, and mastery-sympathy), which exist and function in opposing ways. Motivational profiles indicate the amount of time an individual spends in one or its opposing state in a given dyad over time in a general life situation (i.e., metamotivational dominance) or in a particular situation such as sport and physical activity participation (i.e., situational state balance) (Apter, 2001). Previous research demonstrates a close link between one’s dominance or situational state balance and sport participation patterns and motivation (e.g., Kerr, Au, & Lindner, 2004, 2005; Lindner & Kerr, 2000, 2001; Sit & Lindner, 2005, in press). Individuals however will reverse between opposing states in a given dyad depending on the meanings and motives felt in different situations at different times. Reversals can be “triggered” by environmental stimuli (contingent reversals), frustration (not attaining satisfaction in a current state), and satiation (being in the same state for a period of time). A small number of studies demonstrate that psychological reversals occur between a pair of states and are more associated with external events and frustration than satiation (Kerr & Vlaswinkel, 1995; Males, Kerr, & Gerkovich, 1998). These studies however explore only the telic-paratelic dimension in adults during competitive sports event. Although later studies have identified the factors affecting reversals other than in a sports setting (Hudson & Bates, 2000) and examined different motivational profiles (Hudson & Walker, 2002), little is known about the motivational state patterns experienced by children and the factors affecting their reversals between each dyad on sedentary versus active-based game tasks. A question of whether such state patterns and mechanisms of reversals are associated with one’s situational state balance remains unanswered. The purpose of the proposed research is to examine children’s motivational state patterns and the factors affecting reversals between each pair of states on a game (chess) that can be sedentary or an active laboratory game task. Children’s situational state balance in relation to motivational state patterns and reversals during the game tasks will be identified. The work will also establish if there is any relationship between situational state balance and game participatory behavior in children.

List of Research Outputs

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