title: A comparison of pop-up velocity between younger and older recreational surfers

authors: Enticott, David

subjects: surfing

abstract: Background: The pop-up is the physiological task that places a surfer on a wave. The aim of every recreational surfer is to catch as many open-faced, rideable waves as possible with pop-up velocity being crucial to this. Recent research shows a clear trend of an aging surfing demographic all of whom have the potential to experience an age-related reduction in their pop-up velocity. A slower pop-up would likely limit wave-riding options for these older surfers; therefore, the primary purpose of this study was to determine if age reduces pop-up velocity in intermediate recreational surfers. We hypothesised that pop-up velocity between younger and older recreational surfers would exhibit no statistically significant difference as a result of older surfers having developed efficient movement patterns and skill sets over many years that offset any age-related muscular decrement Methods: Fourteen intermediate recreational surfers (13 males and 1 female) were placed into two groups based on age, a younger group (25.2 ± 9.0 years old, 9.7 ± 10.9 years of surfing experience) and an older group (51.8 ± 6.6 years old, 30.0 ± 9.1 years of surfing experience). The cohort had at least two years surfing experience and did not follow a specific dry-land resistance training programme. Participants completed a simulated pop-up in a controlled laboratory setting with pop-up velocity captured by dual Kistler force plates. A countermovement jump test was also completed by each participant to assess lower-body power and velocity. The intraclass correlation coefficient (ICC), coefficient of variation (CV0, and typical error (TE) were calculated to determine inter-group reliability between the older and younger surfers’ pop-up velocity tests and between pop-up tests featuring simulated paddling strokes and those without. An independent samples t-test was conducted to examine the differences between the two age groups’ pop-up velocity and between pop-up tests featuring simulated paddling strokes and those without. The strength of correlation between surfer age and relative maximal power was assessed with Pearson’s r. Results: The test showed good (ICC 0.75-0.90) reliability and no apparent difference between paddle and non-paddle and the older and younger cohorts; however, the CVs all exceeded 10%. The younger group demonstrated significantly quicker surf pop-ups (1.12±0.16 vs 2.03±0.52 s; p = 0.0009; d = 2.21 [1.10, 4.20]) and relative maximal power (53.8±12.9 vs 41.2±2.2 W·kg−1; p = 0.0252; d = 1.28 [2.84, 0.23]) than the older group. Interestingly, the negative coefficient (slope) that described the overall relationship between age and leg power observed (m= -0.53) was attenuated when looking at surfers over the age of 35 (m=-0.10). Discussion: Loss of pop-up velocity can be expected in older surfers but the typical age-related decline in muscle capability may be offset by surfing. The incorporation of dry-land resistance exercise including power and strength training is recommended to improve pop-up velocity and thus wave wave-catching ability and enjoyment in older surfer. These findings demonstrate positive ramifications of participation in surfing and can support longevity in older recreational surfers. Conclusion: Age clearly had a negative influence on pop-up velocity.

text: A comparison of pop-up velocity between younger and older recreational surfers Background: The pop-up is the physiological task that places a surfer on a wave. The aim of every recreational surfer is to catch as many open-faced, rideable waves as possible with pop-up velocity being crucial to this. Recent research shows a clear trend of an aging surfing demographic all of whom have the potential to experience an age-related reduction in their pop-up velocity. A slower pop-up would likely limit wave-riding options for these older surfers; therefore, the primary purpose of this study was to determine if age reduces pop-up velocity in intermediate recreational surfers. We hypothesised that pop-up velocity between younger and older recreational surfers would exhibit no statistically significant difference as a result of older surfers having developed efficient movement patterns and skill sets over many years that offset any age-related muscular decrement Methods: Fourteen intermediate recreational surfers (13 males and 1 female) were placed into two groups based on age, a younger group (25.2 ± 9.0 years old, 9.7 ± 10.9 years of surfing experience) and an older group (51.8 ± 6.6 years old, 30.0 ± 9.1 years of surfing experience). The cohort had at least two years surfing experience and did not follow a specific dry-land resistance training programme. Participants completed a simulated pop-up in a controlled laboratory setting with pop-up velocity captured by dual Kistler force plates. A countermovement jump test was also completed by each participant to assess lower-body power and velocity. The intraclass correlation coefficient (ICC), coefficient of variation (CV0, and typical error (TE) were calculated to determine inter-group reliability between the older and younger surfers’ pop-up velocity tests and between pop-up tests featuring simulated paddling strokes and those without. An independent samples t-test was conducted to examine the differences between the two age groups’ pop-up velocity and between pop-up tests featuring simulated paddling strokes and those without. The strength of correlation between surfer age and relative maximal power was assessed with Pearson’s r. Results: The test showed good (ICC 0.75-0.90) reliability and no apparent difference between paddle and non-paddle and the older and younger cohorts; however, the CVs all exceeded 10%. The younger group demonstrated significantly quicker surf pop-ups (1.12±0.16 vs 2.03±0.52 s; p = 0.0009; d = 2.21 [1.10, 4.20]) and relative maximal power (53.8±12.9 vs 41.2±2.2 W·kg−1; p = 0.0252; d = 1.28 [2.84, 0.23]) than the older group. Interestingly, the negative coefficient (slope) that described the overall relationship between age and leg power observed (m= -0.53) was attenuated when looking at surfers over the age of 35 (m=-0.10). Discussion: Loss of pop-up velocity can be expected in older surfers but the typical age-related decline in muscle capability may be offset by surfing. The incorporation of dry-land resistance exercise including power and strength training is recommended to improve pop-up velocity and thus wave wave-catching ability and enjoyment in older surfer. These findings demonstrate positive ramifications of participation in surfing and can support longevity in older recreational surfers. Conclusion: Age clearly had a negative influence on pop-up velocity.

year: 2024

title: Rapid response data-driven reconstructions for storm surge around New Zealand

authors: Tausía, J

abstract: In conjunction with tides, storm surge is one major driver of coastal flooding associated with storm events. Because local inundation is strongly modulated by the local shape of the coastline and the bathymetric slope, accurate storm surge predictions using traditional numerical models require the use of very fine grids and are hence resource intensive. Therefore, the performance of a live prediction system based on such methods will likely be subject to a trade-off between prediction accuracy, prediction speed and cost. This study explores the use of data driven methods as an alternative to numerical models to reconstruct the daily storm surge maximum levels along the entire coast of New Zealand. Firstly, several atmospheric predictors are utilized that incorporate different variables, time lags and spatial domains, using 3 statistical models, in a selected number of locations in New Zealand, to find the combination that optimizes the reconstruction. Finally, the storm surge daily maxima are reconstructed with the different statistical models along the entire coast, using the best performing predictor. Results show very good performance for the best atmospheric predictor and statistical model, providing average values of 0.88 for the Pearson correlation coefficient and 4.3 cm for the root mean squared error metric (RMSE) (the average value for the RMSE in the 99% percentile is 8.2 cm). For the Kling–Gupta Efficiency (KGE; incorporating 3 sub-metrics: correlation, bias term and variability term), which is the metric used to rank the models, the average value is 0.82. Our results highlight the suitability of data driven models to simulate storm surge maximum levels, and prove the methodology is appropriate for finding a well performing atmospheric predictor that is able for reconstruct these values. Moreover, this methodology can be also applied to new variables, regions and problems, as there are no physical restrictions on the used predictors nor predictands.

text: Rapid response data-driven reconstructions for storm surge around New Zealand In conjunction with tides, storm surge is one major driver of coastal flooding associated with storm events. Because local inundation is strongly modulated by the local shape of the coastline and the bathymetric slope, accurate storm surge predictions using traditional numerical models require the use of very fine grids and are hence resource intensive. Therefore, the performance of a live prediction system based on such methods will likely be subject to a trade-off between prediction accuracy, prediction speed and cost. This study explores the use of data driven methods as an alternative to numerical models to reconstruct the daily storm surge maximum levels along the entire coast of New Zealand. Firstly, several atmospheric predictors are utilized that incorporate different variables, time lags and spatial domains, using 3 statistical models, in a selected number of locations in New Zealand, to find the combination that optimizes the reconstruction. Finally, the storm surge daily maxima are reconstructed with the different statistical models along the entire coast, using the best performing predictor. Results show very good performance for the best atmospheric predictor and statistical model, providing average values of 0.88 for the Pearson correlation coefficient and 4.3 cm for the root mean squared error metric (RMSE) (the average value for the RMSE in the 99% percentile is 8.2 cm). For the Kling–Gupta Efficiency (KGE; incorporating 3 sub-metrics: correlation, bias term and variability term), which is the metric used to rank the models, the average value is 0.82. Our results highlight the suitability of data driven models to simulate storm surge maximum levels, and prove the methodology is appropriate for finding a well performing atmospheric predictor that is able for reconstruct these values. Moreover, this methodology can be also applied to new variables, regions and problems, as there are no physical restrictions on the used predictors nor predictands.

year: 2023-04-01

title: 'No-body' is my friend: Cultural considerations of young children's 'imaginary companions'

authors: Hayes (Bluett), Shilo Jane

subjects: imaginary companions

abstract: The variegated relationships young children may have during their early childhood education (ECE) years have long been of interest to theorists and teachers alike.  Relationships, and understandings of companionship, can take multiple forms. Our understandings of what these relationships may look like are frequently informed by complex social and cultural constructs; therefore, seeking to apply a one-size-fits-all interpretation is theoretically and culturally problematic, especially when the companions young children may spend time with may be unseen or unnoticed by surrounding adults.
A common Euro-western notion is that unseen companions are not real; hence they are generally referred to in the literature as being imaginary.  In an extensive literature review, this thesis explores whether companionship with the unseen are one of many possible forms of relationships.  Dominant Euro-western claims that such relationships are imaginary are considered critically before the analysis widens in theoretical scope to draw on various alternative cultural accounts.  The analysis draws on the theoretical work of Jacques Derrida, Michel Foucault and Karen Barad, in particular.  An additional exploration considers the author’s own situated experiences of parenting a child who during her childhood years had companions that were unseen to the author.  The final analysis, based on a small selection of carefully chosen autoethnographic accounts, draws on the significance of ancestral inheritance. Within this specific research context that inheritance comprises my daughter’s Māori ancestry and our shared Celtic ancestry. 
Ancestral inheritance provides reflexive companionship for the entire thesis.  Examining inheritance sheds light on ways that traditional Euro-western claims of the imagined worlds of children, and consequently childhood, have produced a legacy of ideas which have subsequently held the term imaginary in place.  These dominant worldviews are shown to fall short in their capacity to cover the diversity of lived realities of children and their unseen (to others) companion(s).  Inheritance also denotes the culturally mediated birthright that may travel alongside a young child and how this birthright may provide insight and alternative cultural knowledge and understandings of various multiform relationship companions.
As a result of analysing several possible perspectives on the relationships under study, this thesis proposes the new term culturally compatible travelling companions (CCTC): companions who travel alongside children as ordinary, expected features of their lifespan.  This shift in term acknowledges that diverse notions of companionship, and the forms this may take, are integral and salient constructions of each culture’s historical and narrative accounts.  
This is timely research, as currently nearly 64% of young children aged between birth and four years of age attend some type of Early Childhood Education (ECE) service in Aotearoa New Zealand (Ministry of Education [MoE], 2019).  The national ECE curriculum document Te Whāriki (MoE, 2017) recognises the significance of young children’s relationships and understands those relationships within the rich and complex cultural knowledge patterning that travels alongside a young child.  
The aim of this research is to add to the theoretical understandings of the forms, functions and features of the multiple, complex relationship companions who may share the lives of young children, whether or not these companions are seen or discernible to those around the children.  It suggests an alternative perspective to the dominant view and offers provocations for those who work alongside young children to think differently about whether these relationship companions are indeed only imaginary.

text: 'No-body' is my friend: Cultural considerations of young children's 'imaginary companions' The variegated relationships young children may have during their early childhood education (ECE) years have long been of interest to theorists and teachers alike.  Relationships, and understandings of companionship, can take multiple forms. Our understandings of what these relationships may look like are frequently informed by complex social and cultural constructs; therefore, seeking to apply a one-size-fits-all interpretation is theoretically and culturally problematic, especially when the companions young children may spend time with may be unseen or unnoticed by surrounding adults.
A common Euro-western notion is that unseen companions are not real; hence they are generally referred to in the literature as being imaginary.  In an extensive literature review, this thesis explores whether companionship with the unseen are one of many possible forms of relationships.  Dominant Euro-western claims that such relationships are imaginary are considered critically before the analysis widens in theoretical scope to draw on various alternative cultural accounts.  The analysis draws on the theoretical work of Jacques Derrida, Michel Foucault and Karen Barad, in particular.  An additional exploration considers the author’s own situated experiences of parenting a child who during her childhood years had companions that were unseen to the author.  The final analysis, based on a small selection of carefully chosen autoethnographic accounts, draws on the significance of ancestral inheritance. Within this specific research context that inheritance comprises my daughter’s Māori ancestry and our shared Celtic ancestry. 
Ancestral inheritance provides reflexive companionship for the entire thesis.  Examining inheritance sheds light on ways that traditional Euro-western claims of the imagined worlds of children, and consequently childhood, have produced a legacy of ideas which have subsequently held the term imaginary in place.  These dominant worldviews are shown to fall short in their capacity to cover the diversity of lived realities of children and their unseen (to others) companion(s).  Inheritance also denotes the culturally mediated birthright that may travel alongside a young child and how this birthright may provide insight and alternative cultural knowledge and understandings of various multiform relationship companions.
As a result of analysing several possible perspectives on the relationships under study, this thesis proposes the new term culturally compatible travelling companions (CCTC): companions who travel alongside children as ordinary, expected features of their lifespan.  This shift in term acknowledges that diverse notions of companionship, and the forms this may take, are integral and salient constructions of each culture’s historical and narrative accounts.  
This is timely research, as currently nearly 64% of young children aged between birth and four years of age attend some type of Early Childhood Education (ECE) service in Aotearoa New Zealand (Ministry of Education [MoE], 2019).  The national ECE curriculum document Te Whāriki (MoE, 2017) recognises the significance of young children’s relationships and understands those relationships within the rich and complex cultural knowledge patterning that travels alongside a young child.  
The aim of this research is to add to the theoretical understandings of the forms, functions and features of the multiple, complex relationship companions who may share the lives of young children, whether or not these companions are seen or discernible to those around the children.  It suggests an alternative perspective to the dominant view and offers provocations for those who work alongside young children to think differently about whether these relationship companions are indeed only imaginary.

year: 2020