title: Blood flow restriction as a method to elicit post activation potentiation in trained female athletes

authors: Wharemate, Jade

subjects: BFR

abstract: It is essential within the sporting context to be able to physically perform at the highest level possible. This demands training methods and tools that can enhance strength and power both chronically and acutely to ensure performance is maximised. Post activation potentiation (PAP) is a method that acutely enhances muscular force output and performance through performing a potentiating stimulus. While PAP has been shown to be effective in certain situations, any acute performance effects are known to be the summation of the potentiating effects and any accumulated fatigue. Blood flow restriction (BFR) is a training modality that has been shown to be effective in enhancing muscle size and strength via occlusion of the arterial flow which may enable the recruitment of high threshold motor units, create a high metabolic stress, and lead to muscular environment suited to adaptation. These physiological effects, combined with a low level of central fatigue, may combine to provide a situation where PAP is achieved. To date, only one study has investigated the effects of using BFR as a potentiation tool, and no research has been performed on female participants. 
This thesis starts by evaluating and synthesizing the existing literature regarding both PAP and BFR training illustrating that there are a variety of performance benefits of using both PAP and BFR (Chapter One). Of the studies identified, 76% showed high intensity-low volume resistance exercise to be effective in inducing PAP, 86% showed WBV training to be effective, and 83% showed ‘other’ methods to be effective. Overall, 10 of the 42 studies identified (29%) were unsuccessful at eliciting PAP. The literature also suggests that a higher methodological quality of training characteristics, especially relating to the inclusion of female participants, is crucial to ensure the most efficient approach to using BFR to induce PAP. Specifically, of the 42 studies identified that assessed the effects of lower body PAP on sprint and jump performance in athletes, only two studies (4.8%) were conducted in female-only cohorts, and none of them reported details of the menstrual phase (Chapter One). 
Chapter Two of this thesis examined the inter-session reliability of both vertical and horizontal explosive power in trained female athletes over a 3-day period utilised in the subsequent experimental chapter to inform the typical error of measurement. The reliability sessions assessed the components of the force-velocity profile for horizontal (20-m running sprint) and vertical (squat jump at body weight, 24 kg, and 48 kg), as well as power using an OptoJumpᵀᴹ and a StalkerATS Radar Gun. Intraclass correlation coefficients (ICC), typical error (TE) and coefficient of variation (CV) with 95% confidence intervals were calculated to compute relative and absolute reliability of measures. The force-velocity component metrics that exhibited acceptable reliability included V0ᵥₑᵣₜ [CV:5.2%, ICC: 0.81 (good)], F0ᵥₑᵣₜ [CV: 6.2%, ICC: 0.7 (good)], and power Pmaxᵥₑᵣₜ [CV: 3.6%, ICC: 0.89 (good)]; while velocity V0ₕₒᵣᵢ₂) exhibited a reliable CV of 9.8%. The performance metrics exhibited acceptable reliability for BW [CV: 6.9%, ICC: 0.91 (good)] with a low typical error (1.5 cm). When compared to BW jump height measures, sprint speed presented having acceptable reliability [CV: 5.5%, ICC: 0.73 (good)], however, the typical error (1.1 km/h) can be considered large. The reliability results for 24 kg weighted jump exhibited a CV slightly over acceptable range [CV: 10.2%, ICC: 0.84 (good)]; while the data collected for 48 kg weighted jump showed acceptable ICC results, but a poor CV [CV: 36.2%, ICC: 0.84 (good)]. The correlation data demonstrated that Pmaxᵥₑᵣₜ was very strongly correlated with jump performance (r = 0.97), but the association with F0ᵥₑᵣₜ was weak (r = 0.22). In contrast, both Pmaxₕₒᵣᵢ₂ (r = 0.71) and F0ₕₒᵣᵢ₂ (r = 0.65), were strongly related to sprint speed. Pmaxᵥₑᵣₜ was very strongly related to sprint speed (r =0.83). Additionally, there was a strong relationship between Pmaxᵥₑᵣₜ and Pmaxₕₒᵣᵢ₂ (r = 0.63), but the relationships between the corresponding horizontal and vertical F0 and V0 were weak. There was no indication that high levels of theoretical maximal force (F0ₕₒᵣᵢ₂ or F0ᵥₑᵣₜ) were related to a greater potentiation response. 
The penultimate chapter (Chapter Three) investigated the effects of using BFR to elicit PAP in well-trained female athletes. The athletes completed the testing protocols a minimum of 2-days apart and running sprint and squat jump were assessed 4 and 8-min post the PAP intervention. The PAP intervention included completing four sets of bodyweight squats (30, 15, 15, 15 repetitions separated by 30 second rest intervals) with occlusion cuffs applied to the proximal region of the thigh inflated to 180 mmHg; whereas, the control intervention performed the same stimulus without occlusion. With the potentiating stimulus being vertically oriented, we hypothesised that this intervention would be more effective in jumping than sprinting. A 2-way (group x time) repeated-measure ANOVA used to analyse jump performance showed a negative effect of time in bodyweight (p= 1.01x10⁻⁷ ) and 24 kg jump (p= 2.97x10⁻⁶) conditions. An interaction effect was observed in the bodyweight jump (p = 0.0436), and post hoc analyses showed that the decrease in jump height was greater in the CON condition. Thus, while there was no evidence of potentiation in the body weight squat jump, there was a small significant difference in the decrease observed from Pre to Post 4 (p=0.0409) with a large effect size (ES=1.01) indicating that there was less fatigue between Pre and Post 4 for the BFR condition compared to the CON condition. The repeated-measures ANOVA used to analyse sprint potentiation reported no evidence of potentiation in sprint performance at any time point after the conditioning stimulus, results were considered unclear (Post 4: d = 0.22 ±0.42) or trivial (Post 8: d= -0.16 ±0.24). 
Overall, the results did not show any significant differences in performance between the two conditions. Therefore, concluding that the BFR protocol used in this study failed to elicit potentiation in female athletes. The literature suggests that when there is an optimal balance between potentiation and fatigue it can be utilised to improve performance and low resistance exercise combined with blood flow restriction has been shown to successfully improve performance in males. However, there is very a limited amount of research done using 6 blood flow restriction in females. Hence, the aim of this thesis was to unpack the literature regarding post activation potentiation and blood flow restriction and use it to guide our study in an attempt to potentiate an improvement in jump and sprint performance using BFR in trained females.

text: Blood flow restriction as a method to elicit post activation potentiation in trained female athletes It is essential within the sporting context to be able to physically perform at the highest level possible. This demands training methods and tools that can enhance strength and power both chronically and acutely to ensure performance is maximised. Post activation potentiation (PAP) is a method that acutely enhances muscular force output and performance through performing a potentiating stimulus. While PAP has been shown to be effective in certain situations, any acute performance effects are known to be the summation of the potentiating effects and any accumulated fatigue. Blood flow restriction (BFR) is a training modality that has been shown to be effective in enhancing muscle size and strength via occlusion of the arterial flow which may enable the recruitment of high threshold motor units, create a high metabolic stress, and lead to muscular environment suited to adaptation. These physiological effects, combined with a low level of central fatigue, may combine to provide a situation where PAP is achieved. To date, only one study has investigated the effects of using BFR as a potentiation tool, and no research has been performed on female participants. 
This thesis starts by evaluating and synthesizing the existing literature regarding both PAP and BFR training illustrating that there are a variety of performance benefits of using both PAP and BFR (Chapter One). Of the studies identified, 76% showed high intensity-low volume resistance exercise to be effective in inducing PAP, 86% showed WBV training to be effective, and 83% showed ‘other’ methods to be effective. Overall, 10 of the 42 studies identified (29%) were unsuccessful at eliciting PAP. The literature also suggests that a higher methodological quality of training characteristics, especially relating to the inclusion of female participants, is crucial to ensure the most efficient approach to using BFR to induce PAP. Specifically, of the 42 studies identified that assessed the effects of lower body PAP on sprint and jump performance in athletes, only two studies (4.8%) were conducted in female-only cohorts, and none of them reported details of the menstrual phase (Chapter One). 
Chapter Two of this thesis examined the inter-session reliability of both vertical and horizontal explosive power in trained female athletes over a 3-day period utilised in the subsequent experimental chapter to inform the typical error of measurement. The reliability sessions assessed the components of the force-velocity profile for horizontal (20-m running sprint) and vertical (squat jump at body weight, 24 kg, and 48 kg), as well as power using an OptoJumpᵀᴹ and a StalkerATS Radar Gun. Intraclass correlation coefficients (ICC), typical error (TE) and coefficient of variation (CV) with 95% confidence intervals were calculated to compute relative and absolute reliability of measures. The force-velocity component metrics that exhibited acceptable reliability included V0ᵥₑᵣₜ [CV:5.2%, ICC: 0.81 (good)], F0ᵥₑᵣₜ [CV: 6.2%, ICC: 0.7 (good)], and power Pmaxᵥₑᵣₜ [CV: 3.6%, ICC: 0.89 (good)]; while velocity V0ₕₒᵣᵢ₂) exhibited a reliable CV of 9.8%. The performance metrics exhibited acceptable reliability for BW [CV: 6.9%, ICC: 0.91 (good)] with a low typical error (1.5 cm). When compared to BW jump height measures, sprint speed presented having acceptable reliability [CV: 5.5%, ICC: 0.73 (good)], however, the typical error (1.1 km/h) can be considered large. The reliability results for 24 kg weighted jump exhibited a CV slightly over acceptable range [CV: 10.2%, ICC: 0.84 (good)]; while the data collected for 48 kg weighted jump showed acceptable ICC results, but a poor CV [CV: 36.2%, ICC: 0.84 (good)]. The correlation data demonstrated that Pmaxᵥₑᵣₜ was very strongly correlated with jump performance (r = 0.97), but the association with F0ᵥₑᵣₜ was weak (r = 0.22). In contrast, both Pmaxₕₒᵣᵢ₂ (r = 0.71) and F0ₕₒᵣᵢ₂ (r = 0.65), were strongly related to sprint speed. Pmaxᵥₑᵣₜ was very strongly related to sprint speed (r =0.83). Additionally, there was a strong relationship between Pmaxᵥₑᵣₜ and Pmaxₕₒᵣᵢ₂ (r = 0.63), but the relationships between the corresponding horizontal and vertical F0 and V0 were weak. There was no indication that high levels of theoretical maximal force (F0ₕₒᵣᵢ₂ or F0ᵥₑᵣₜ) were related to a greater potentiation response. 
The penultimate chapter (Chapter Three) investigated the effects of using BFR to elicit PAP in well-trained female athletes. The athletes completed the testing protocols a minimum of 2-days apart and running sprint and squat jump were assessed 4 and 8-min post the PAP intervention. The PAP intervention included completing four sets of bodyweight squats (30, 15, 15, 15 repetitions separated by 30 second rest intervals) with occlusion cuffs applied to the proximal region of the thigh inflated to 180 mmHg; whereas, the control intervention performed the same stimulus without occlusion. With the potentiating stimulus being vertically oriented, we hypothesised that this intervention would be more effective in jumping than sprinting. A 2-way (group x time) repeated-measure ANOVA used to analyse jump performance showed a negative effect of time in bodyweight (p= 1.01x10⁻⁷ ) and 24 kg jump (p= 2.97x10⁻⁶) conditions. An interaction effect was observed in the bodyweight jump (p = 0.0436), and post hoc analyses showed that the decrease in jump height was greater in the CON condition. Thus, while there was no evidence of potentiation in the body weight squat jump, there was a small significant difference in the decrease observed from Pre to Post 4 (p=0.0409) with a large effect size (ES=1.01) indicating that there was less fatigue between Pre and Post 4 for the BFR condition compared to the CON condition. The repeated-measures ANOVA used to analyse sprint potentiation reported no evidence of potentiation in sprint performance at any time point after the conditioning stimulus, results were considered unclear (Post 4: d = 0.22 ±0.42) or trivial (Post 8: d= -0.16 ±0.24). 
Overall, the results did not show any significant differences in performance between the two conditions. Therefore, concluding that the BFR protocol used in this study failed to elicit potentiation in female athletes. The literature suggests that when there is an optimal balance between potentiation and fatigue it can be utilised to improve performance and low resistance exercise combined with blood flow restriction has been shown to successfully improve performance in males. However, there is very a limited amount of research done using 6 blood flow restriction in females. Hence, the aim of this thesis was to unpack the literature regarding post activation potentiation and blood flow restriction and use it to guide our study in an attempt to potentiate an improvement in jump and sprint performance using BFR in trained females.

year: 2021

title: Kinetic studies of redox and related reactions of some new isoalloxazines

authors: Gumbley, Stewart John

abstract: This thesis describes the synthesis of three new isoalloxazines with special structural characteristics which we hoped would, and in fact did, modify their chemical reactivity so as to improve our understanding of mechanisms of flavin reactions generally: kinetic studies of their reactions with a dithiol, reduced nicotinamide and sulphite were made.

A new general synthesis is described for the preparation of o-nitro-(N-alkylamino) aromatic compounds via nucleophilic displacement by alkylamine of a methoxy group ortho to a nitro group. Two new compounds, the isomers 1-(2'-hydroxyethylamino)-2-nitronaphthalene and 2-(2'-hydroxyethylamino)-1-nitronaphthalene, were prepared by this method.

These compounds were used to synthesize two isoalloxazines which each have an additional benzene ring fused either at the 6,7-bond of the isoalloxazine nucleus (7-(2'-hydroxyethyl)-10-methylnaphtho[1,2-g]pteridine- 9,11(7H,10H)-dione; isoalloxazine A) or at the 8,9-bond (12-(2'-hydroxyethyl)-9-methylnaphtho[2,1-g]pteridine- 8,10(9H,12H)-dione; isoalloxazine B). The third new isoalloxazine (10-(2'-hydroxyethyl)-3-methylbenzo[g]pteridine- 2,4(3H,10H)-dione; isoalloxazine C) was prepared by a conventional route.

Kinetic studies, the first recorded for isoalloxazines of the type of A and B, were undertaken for reactions with 1,3-dithio-2-propanol, with NADH and with sulphite.

In the case of the dithiopropanol reaction, a linear free-energy relationship was observed between the logarithm of the second order rate constant and the polarographic half-wave potential, E⅟₂ (slope 26 ± 1 V⁻¹). The conclusion drawn from this is that, if the redox reaction occurs through an addition-elimination sequence, the 5-, 6- and 8-positions are not essential centres for thiol oxidation.

In the case of the reaction with NADH, direct evidence was obtained for the formation of a kinetically important complex between the isoalloxazine and NADH from the observation of saturation kinetics. This is the first reported instance of the observation of such direct evidence for complex formation with NADH. The rate constants for the three isoalloxazines follow the reverse order expected from the E⅟₂ values and from the rates of reaction with DTP. The equilibrium constants (Kₑ) for the complexing of tryptophan with the isoalloxazines were measured by fluorescence quenching. A linear free-energy relationship was not observed between the logarithm of Kₑ and the logarithm of the rate constant for NADH oxidation. It was concluded that the unexpectedly high rate of reaction of A relative to that of B was due to the formation by A of a complex with NADH closer to the hydride acceptor site, the 5-position, than is the case for isoalloxazine B; and that the productivity of the complex therefore is markedly determined by the orientation of the NADH molecule with respect to the isoalloxazine within the complex.

The anaerobic nucleophilic addition reaction of sulphite with isoalloxazines A and C is a two step process of the form X⇌Y→Z, whereas the reaction with B is a single equilibrium step. The reduced isoalloxazine products from A and C are oxidized by molecular oxygen to new isoalloxazines but that from B is not. The new isoalloxazine from C reacts further with sulphite to yield a reduced species different from that of the anaerobic reaction, while the product from A does not react further. These observations provide support for the mechanism previously suggested in the literature for the reaction of sulphite with isoalloxazines. A small rate depression was observed for A relative to B and C in a plot of logarithm of rate constant against E ⅟₂. This is interpreted as being due to steric crowding at the 5-position caused by the α-hydrogen on the naphthalene moiety, an effect not observed in the dithiol reaction which more likely involves nucleophilic addition at the 4a- rather than the 5-position.

text: Kinetic studies of redox and related reactions of some new isoalloxazines This thesis describes the synthesis of three new isoalloxazines with special structural characteristics which we hoped would, and in fact did, modify their chemical reactivity so as to improve our understanding of mechanisms of flavin reactions generally: kinetic studies of their reactions with a dithiol, reduced nicotinamide and sulphite were made.

A new general synthesis is described for the preparation of o-nitro-(N-alkylamino) aromatic compounds via nucleophilic displacement by alkylamine of a methoxy group ortho to a nitro group. Two new compounds, the isomers 1-(2'-hydroxyethylamino)-2-nitronaphthalene and 2-(2'-hydroxyethylamino)-1-nitronaphthalene, were prepared by this method.

These compounds were used to synthesize two isoalloxazines which each have an additional benzene ring fused either at the 6,7-bond of the isoalloxazine nucleus (7-(2'-hydroxyethyl)-10-methylnaphtho[1,2-g]pteridine- 9,11(7H,10H)-dione; isoalloxazine A) or at the 8,9-bond (12-(2'-hydroxyethyl)-9-methylnaphtho[2,1-g]pteridine- 8,10(9H,12H)-dione; isoalloxazine B). The third new isoalloxazine (10-(2'-hydroxyethyl)-3-methylbenzo[g]pteridine- 2,4(3H,10H)-dione; isoalloxazine C) was prepared by a conventional route.

Kinetic studies, the first recorded for isoalloxazines of the type of A and B, were undertaken for reactions with 1,3-dithio-2-propanol, with NADH and with sulphite.

In the case of the dithiopropanol reaction, a linear free-energy relationship was observed between the logarithm of the second order rate constant and the polarographic half-wave potential, E⅟₂ (slope 26 ± 1 V⁻¹). The conclusion drawn from this is that, if the redox reaction occurs through an addition-elimination sequence, the 5-, 6- and 8-positions are not essential centres for thiol oxidation.

In the case of the reaction with NADH, direct evidence was obtained for the formation of a kinetically important complex between the isoalloxazine and NADH from the observation of saturation kinetics. This is the first reported instance of the observation of such direct evidence for complex formation with NADH. The rate constants for the three isoalloxazines follow the reverse order expected from the E⅟₂ values and from the rates of reaction with DTP. The equilibrium constants (Kₑ) for the complexing of tryptophan with the isoalloxazines were measured by fluorescence quenching. A linear free-energy relationship was not observed between the logarithm of Kₑ and the logarithm of the rate constant for NADH oxidation. It was concluded that the unexpectedly high rate of reaction of A relative to that of B was due to the formation by A of a complex with NADH closer to the hydride acceptor site, the 5-position, than is the case for isoalloxazine B; and that the productivity of the complex therefore is markedly determined by the orientation of the NADH molecule with respect to the isoalloxazine within the complex.

The anaerobic nucleophilic addition reaction of sulphite with isoalloxazines A and C is a two step process of the form X⇌Y→Z, whereas the reaction with B is a single equilibrium step. The reduced isoalloxazine products from A and C are oxidized by molecular oxygen to new isoalloxazines but that from B is not. The new isoalloxazine from C reacts further with sulphite to yield a reduced species different from that of the anaerobic reaction, while the product from A does not react further. These observations provide support for the mechanism previously suggested in the literature for the reaction of sulphite with isoalloxazines. A small rate depression was observed for A relative to B and C in a plot of logarithm of rate constant against E ⅟₂. This is interpreted as being due to steric crowding at the 5-position caused by the α-hydrogen on the naphthalene moiety, an effect not observed in the dithiol reaction which more likely involves nucleophilic addition at the 4a- rather than the 5-position.

year: 1976

title: Viruses without vaccines, or valuing indigenous research? The tensions of introducing Western research assessment practices into an indigenous university

authors: Bruce Ferguson, Pip

abstract: Over my past twenty-five years of educational practice, I have striven to develop a better understanding of indigenous ways of being and doing (in New Zealand’s case, this involves the values and knowledge of Māori). I have done this by visiting and occasionally staying on marae (Māori gathering-places); by reading relevant literature; by engaging in conversations with knowledgeable scholars and by researching the impact of Western practices on indigenous peoples.

In 2003 I managed a research team for Te Wānanga o Aotearoa, a Māori tertiary institution with branches across the country. Our Tertiary Education Commission had just introduced a variation of the English RAE, called the Performance-Based Research Fund, through which government research funds would henceforth be distributed. In collaboration with Māori colleagues, we chose to enter this process, believing that Māori research would be recognised and funded by our participation.

While this proved to be the case, there were significant examples of values clashes, such as the requirement for people to ‘boast’ of their research achievements in a context where such boasting is anathema; to claim ownership of knowledge where tradition often indicates that knowledge is not the property of individuals; and worst, at one point I found myself accused by my Māori manager of introducing ‘viruses without vaccines’. By this he meant Westernised ideas and practices which appeared to be benevolent but in fact were toxic (the idea derives from white settlers who apparently gave native Americans blankets permeated with a virus, causing thousands to die).

In this paper I will explore tensions of operating cross-culturally, and whether/how we can protect people from unintended toxic consequences of intended benevolent actions.

text: Viruses without vaccines, or valuing indigenous research? The tensions of introducing Western research assessment practices into an indigenous university Over my past twenty-five years of educational practice, I have striven to develop a better understanding of indigenous ways of being and doing (in New Zealand’s case, this involves the values and knowledge of Māori). I have done this by visiting and occasionally staying on marae (Māori gathering-places); by reading relevant literature; by engaging in conversations with knowledgeable scholars and by researching the impact of Western practices on indigenous peoples.

In 2003 I managed a research team for Te Wānanga o Aotearoa, a Māori tertiary institution with branches across the country. Our Tertiary Education Commission had just introduced a variation of the English RAE, called the Performance-Based Research Fund, through which government research funds would henceforth be distributed. In collaboration with Māori colleagues, we chose to enter this process, believing that Māori research would be recognised and funded by our participation.

While this proved to be the case, there were significant examples of values clashes, such as the requirement for people to ‘boast’ of their research achievements in a context where such boasting is anathema; to claim ownership of knowledge where tradition often indicates that knowledge is not the property of individuals; and worst, at one point I found myself accused by my Māori manager of introducing ‘viruses without vaccines’. By this he meant Westernised ideas and practices which appeared to be benevolent but in fact were toxic (the idea derives from white settlers who apparently gave native Americans blankets permeated with a virus, causing thousands to die).

In this paper I will explore tensions of operating cross-culturally, and whether/how we can protect people from unintended toxic consequences of intended benevolent actions.

year: 2012