title: Effects of a caffeine-carbohydrate mouth rinsing on sprinting kinetics and kinematics in fasted athletes

authors: Washif, Jad Adrian

abstract: Carbohydrate mouth rinsing during an intermittent fasting has been reported to be advantageous for endurance performance; however, there appears to be no clear effect on repeated sprints. What has not been investigated previously is the effects of combined caffeine and carbohydrate (CAF-CHO) mouth rinsing on speed-endurance performance commonly performed by track and field athletes during a fasted state.
PURPOSE: To determine the influence of CAF-CHO mouth rinsing on sprinting kinetics and kinematics, as well as subjective exertion during a speed-endurance bout performed in a fasted state. METHOD: In a counterbalanced, single-blind random order design, eleven (n = 11) well-trained National level male sprinters and middledistance runners performed three 15-sec all-out sprints on a Woodway nonmotorized force treadmill, interspersed with 2-min active recovery between sprints. Athletes rinsed 25 ml of CAF-CHO (4g carbohydrate, 5 mg caffeine), or a similarly coloured placebo solution (PLA) prior to warm-up (30-min pre-trial), 1-min pre-trial, and the mid-way of each period of active recovery. On one occasion, no mouth rinse (NMR) was administered. The study was conducted within the second and third quarters of Ramadan, and each session separated by at least 72 hours. RESULTS: At the start of each trial, the rating of perceived exertions (RPE), readiness to train, blood glucose, and lactate concentrations were similar (p > 0.05). A significant primary effect of trial (3 x 15 seconds sprint) was observed for the distance (p = 0.019), revealing a longer average distance achieved in the CAF-CHO compared to PLA trial (69.80 + 3.57 vs. 68.08 + 3.22; p = 0.026; EF: 0.5), and NMR (69.69 + 3.82; p = 0.680; EF: 0.2). The difference between NMR and PLA also approached significance (p = 0.073; ES: 0.5). The CAF-CHO intervention also obtained better results in all other sprint measures such as average velocity, peak acceleration, and peak horizontal force, although these differences were not significant. Post-trial RPE was higher during NMR (7.23 + 1.92) as compared to CAF-CHO (6.54 + 2.15) and PLA (6.38 + 1.94) (p = 0.247).
CONCLUSION: In challenging metabolic conditions, CAF-CHO mouth rinsing might have potential to improve measures of sprint training performance with a positive ergogenic effect on speed endurance performance

text: Effects of a caffeine-carbohydrate mouth rinsing on sprinting kinetics and kinematics in fasted athletes Carbohydrate mouth rinsing during an intermittent fasting has been reported to be advantageous for endurance performance; however, there appears to be no clear effect on repeated sprints. What has not been investigated previously is the effects of combined caffeine and carbohydrate (CAF-CHO) mouth rinsing on speed-endurance performance commonly performed by track and field athletes during a fasted state.
PURPOSE: To determine the influence of CAF-CHO mouth rinsing on sprinting kinetics and kinematics, as well as subjective exertion during a speed-endurance bout performed in a fasted state. METHOD: In a counterbalanced, single-blind random order design, eleven (n = 11) well-trained National level male sprinters and middledistance runners performed three 15-sec all-out sprints on a Woodway nonmotorized force treadmill, interspersed with 2-min active recovery between sprints. Athletes rinsed 25 ml of CAF-CHO (4g carbohydrate, 5 mg caffeine), or a similarly coloured placebo solution (PLA) prior to warm-up (30-min pre-trial), 1-min pre-trial, and the mid-way of each period of active recovery. On one occasion, no mouth rinse (NMR) was administered. The study was conducted within the second and third quarters of Ramadan, and each session separated by at least 72 hours. RESULTS: At the start of each trial, the rating of perceived exertions (RPE), readiness to train, blood glucose, and lactate concentrations were similar (p > 0.05). A significant primary effect of trial (3 x 15 seconds sprint) was observed for the distance (p = 0.019), revealing a longer average distance achieved in the CAF-CHO compared to PLA trial (69.80 + 3.57 vs. 68.08 + 3.22; p = 0.026; EF: 0.5), and NMR (69.69 + 3.82; p = 0.680; EF: 0.2). The difference between NMR and PLA also approached significance (p = 0.073; ES: 0.5). The CAF-CHO intervention also obtained better results in all other sprint measures such as average velocity, peak acceleration, and peak horizontal force, although these differences were not significant. Post-trial RPE was higher during NMR (7.23 + 1.92) as compared to CAF-CHO (6.54 + 2.15) and PLA (6.38 + 1.94) (p = 0.247).
CONCLUSION: In challenging metabolic conditions, CAF-CHO mouth rinsing might have potential to improve measures of sprint training performance with a positive ergogenic effect on speed endurance performance

year: 2018

title: Stability in the South Pacific surface marine ¹⁴C reservoir over the last 750 years. Evidence from American Samoa, the southern Cook Islands and the Marquesas

authors: Petchey, Fiona

subjects: ΔR

abstract: Although minor climatic and sea-level changes have been documented for the South Pacific during the late Holocene, our understanding of the consequent impact of these changes on the marine ¹⁴C reservoir, and therefore the ¹⁴C content of shellfish, is limited. Ultimately, this has implications for documenting the chronology of human movement and adaptation in this region. In this paper we compare marine reservoir (ΔR) data obtained from tightly controlled archaeological proveniences with known-age, pre-AD 1950 shells from the southern Cook Islands, American Samoa, and Marquesas Islands. Results indicate that there has been no significant change in the near-shore marine reservoir in these three locations over the last ca. 750 years. Furthermore, known-age, pre-AD 1950 shell samples provide more precise ΔR values for use in sample calibration than archaeological paired shell/charcoal samples. This is attributed in part to the limitations of assigning provenance and age to material from archaeological sites. On the basis of these results we conclude that the known-age, pre-AD 1950 shell derived ΔR values can be used to calibrate shell ¹⁴C results from deposits of late Holocene age.

text: Stability in the South Pacific surface marine ¹⁴C reservoir over the last 750 years. Evidence from American Samoa, the southern Cook Islands and the Marquesas Although minor climatic and sea-level changes have been documented for the South Pacific during the late Holocene, our understanding of the consequent impact of these changes on the marine ¹⁴C reservoir, and therefore the ¹⁴C content of shellfish, is limited. Ultimately, this has implications for documenting the chronology of human movement and adaptation in this region. In this paper we compare marine reservoir (ΔR) data obtained from tightly controlled archaeological proveniences with known-age, pre-AD 1950 shells from the southern Cook Islands, American Samoa, and Marquesas Islands. Results indicate that there has been no significant change in the near-shore marine reservoir in these three locations over the last ca. 750 years. Furthermore, known-age, pre-AD 1950 shell samples provide more precise ΔR values for use in sample calibration than archaeological paired shell/charcoal samples. This is attributed in part to the limitations of assigning provenance and age to material from archaeological sites. On the basis of these results we conclude that the known-age, pre-AD 1950 shell derived ΔR values can be used to calibrate shell ¹⁴C results from deposits of late Holocene age.

year: 2009

title: Renewal and resistance: Moko in contemporary New Zealand

authors: Nikora, Linda Waimarie

subjects: maori

abstract: Moko is still here, contrary to the widely held belief that the art and custom of moko-Maori skin adornment-had vanished from New Zealand communities. Over the last two decades an increasingly visible number of Maori have revived and renewed the practice, taking colour into their skin. As an indigenous people, re-taking moko confronts and refutes the myth of a 'dying race'. It calls on Maori to recommit to strong Maori identities, customs and traditions and challenges the viewer to re-examine their social representations of moko and moko wearers. This paper reports the resistance strategies of a group of 83 moko wearers. Strategies include (1) educating, representing and reconstructing; (2) invalidating and minimizing representations; (3) building and enhancing social networks; and (4) securing cultural identity and pride. They reflect the celebration of cultural resilience.

text: Renewal and resistance: Moko in contemporary New Zealand Moko is still here, contrary to the widely held belief that the art and custom of moko-Maori skin adornment-had vanished from New Zealand communities. Over the last two decades an increasingly visible number of Maori have revived and renewed the practice, taking colour into their skin. As an indigenous people, re-taking moko confronts and refutes the myth of a 'dying race'. It calls on Maori to recommit to strong Maori identities, customs and traditions and challenges the viewer to re-examine their social representations of moko and moko wearers. This paper reports the resistance strategies of a group of 83 moko wearers. Strategies include (1) educating, representing and reconstructing; (2) invalidating and minimizing representations; (3) building and enhancing social networks; and (4) securing cultural identity and pride. They reflect the celebration of cultural resilience.

year: 2007