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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Acute effects of three recovery techniques on certain physical, motor performance and haematological components in university-level rugby players / Adele Broodryk

Broodryk, Adele January 2015 (has links)
Rugby has become a popular team sport worldwide with players training harder and competing more frequently, placing a great physiological demand on their bodies. To retain this performance level, players need to recover sufficiently between training and competitions. Two popular recovery techniques used are cold water immersion (CWI) and contrast water therapy (CWT). Despite numerous publications a lack still exists with regard to these specific recovery methods on physical and haematological parameters. Against this background, the main objectives of this study were firstly, to determine the effects of CWI compared to those of passive recovery (PAR) over a 48-hour period on physical and haematological parameters after an intense anaerobic exercise session in a cohort of male university-level rugby players. Secondly, to determine the effects of CWT compared to those of PAR over a 48-hour period on physical and haematological parameters after an intense anaerobic exercise session in a cohort of male university-level rugby players. Twenty-three rugby players of the North-West University participated in the study. The players were randomly assigned to either a control (n = 11; age: 20.1±0.3 y) or experimental (n = 12; age: 19.9±0.3 y) group. Participants reported to the laboratory where base line measurements were taken on certain physical (vertical jump test (VJT) height, VJT peak speed, VJT peak power and grip strength) and haematological (base excess (BEx), blood lactate (BLa-), calcium (Ca+), bicarbonate (HCO3), haemoglobin, haematocrit, pH level, partial oxygen level (PO2), partial carbon dioxide (PCO2), plasma glucose, potassium (K+), saturated oxygen (SO2), sodium (Na+) and total carbon dioxide (TCO2)) components. Thereafter participants were accompanied to the field to complete an intense anaerobic exercise session, followed by a recovery period of either CWI vs. PAR (week 1) or CWT vs. PAR (week 2). The recovery session comprised of either sitting passively in a still area (PAR), or immersion of CWI (8–10°C), or alternating immersions of five cycles between cold (1 min; 8–10°C) and warm water (3min; 40-42°C), totalling 20 minutes. Exactly three minutes, 24 and 48 hours after the recovery intervention all the measurements were re-taken to assess acute and longer-term effects of recovery. Descriptive statistics were followed by a linear mixed model analysis with an autoregressive 1 heterogeneous (AR1-Heterogeneous) structure, and between-group differences were examined using a one-way analysis of variance (ANOVA). Significance was set at p ≤0.05. Effect sizes were calculated to determine practical significance per recovery intervention as well as within groups. CWI indicated better recovery than PAR, with three out of the nine variables (BLa-, Na+ and haemoglobin) returning at 0 h post-recovery, and five (PO2, plasma glucose, VJT height, VJT peak power, VJT peak speed) only at 24 h post-CWI. In contrast, the PAR-group did not demonstrate recovery in any of the variables at 0 h post-PAR. However, an improvement was seen in VJT height across all time points. Four (BLa-, haemoglobin, VJT peak power and VJT peak speed) out of a possible nine variables recovered at 24 h with an additional two (PO2 and grip strength) variables showing recuperation at 48 h. A significant decrease (p ≤0.05) was seen in VJT height, PO2 and Na+ from post-anaerobic to immediately following either CWI or PAR (except for VJT height). Significant increases (p ≤0.05) were observed in VJT height, plasma glucose, and Na+ from 0 h post-recovery to 48 h post-recovery for both CWI and PAR. PO2 also significantly increased (p ≤0.05) from 0 h to 24 and 48 h post-CWI and for the PAR-group at 48 h. CWI tended to have a faster recovery rate than PAR over a 24-h period. The CWT vs. PAR showed the same trend, at 0-hours, six variables (BLa-, haemoglobin, VJT-height, VJT peak-power, VJT peak-speed and grip strength) was restored to base line, whereas plasma glucose recovered at 24-hours post-CWT. In addition, players’ jump and grip strength performance improved from base line. The PAR-group demonstrated recovery at 0 hours in four variables (BLa-, VJT height, VJT peak-speed and grip strength), and two variables (Na+ and haemoglobin) at 24-hours and plasma glucose at 48 hours. A significant decrease (p ≤0.05) was seen in haemoglobin and BLa- from post-anaerobic to either 24 or 48 hours for both groups. A significant increase in plasma glucose and PO2 from 0 to 24 hours was observed in both groups. No significant intergroup change in physical components was noticed. However, intergroup results indicated CWT to be superior to PAR with statistical significance observed in BLa- and grip strength (p ≤0.05) at various time points. The conclusion drawn from the above-mentioned results is that a recovery session comprising either 20-minutes of CWI or CWT may lead to significantly better physical components and restoration of haematological components in university-level rugby players compared to that of passive recovery. However, a detrimental effect was noticed in some components over the recovery period. / MA (Sport Science), North-West University, Potchefstroom Campus, 2015
2

A comparison between the acute effects of different recovery techniques on the mood states of university-level rugby players / Erika van der Bijl

Van der Bijl, Erika January 2014 (has links)
Rugby union training and match-play are physiologically and psychologically very demanding and the execution of post-exercise recovery techniques in players‟ training regimes are therefore necessary to aid in the physiological and psychological restoration of athletes‟ training and performance abilities. However, despite numerous research findings with regard to the efficiency of especially cold water immersion (CWI), contrast water therapy (CWT) and passive recovery (PAR) on the physiological recovery of athletes post-exercise, only a limited number of researchers have examined the possible benefits of these recovery techniques on the psychological recovery of athletes. Consequently, the objectives of this study were firstly to determine the difference between the acute effects of CWI and PAR on the mood states (anger, confusion, depression, fatigue, tension and vigour) and the energy index of university-level rugby players post-exercise, and secondly to determine the difference between the acute effects of CWT and PAR on the mood states and the energy index of university-level rugby players post-exercise. Twenty-three under/21 university-level rugby players (age 20.1 ± 0.41) of a South African university club voluntarily participated in this study. The players were randomly divided into a control group (PAR) and an experimental group (CWI or CWT). Participants completed the Stellenbosch Mood Scale (STEMS) questionnaire over four time periods: during the morning (baseline); before completion of a high-intensity anaerobic training session (pre-anaerobic); after completion of a high-intensity anaerobic training session of 15 minutes (post-anaerobic) and after completion of a 20-minute recovery session (post-recovery). Blood lactate measurements were also taken 3 minutes after completion of the anaerobic session. To test the first objective, the experimental group completed 20 minutes of CWI, whereas the control group recovered passively for the same time period. For the purpose of the second objective, the experimental group completed 20 minutes of CWT, whereas the control group recovered passively for the same time period. Although the dependent t-test and effect size results of the first study showed that the experimental group (CWI) experienced no significant changes from the pre-anaerobic to post-recovery time periods for any of the STEMS subscale values or the energy index, the control group‟s (PAR) confusion, depression and tension subscale values decreased significantly (p < 0.05) from the pre-anaerobic to the post-recovery time periods. Despite these changes, the one-way between groups‟ analysis of covariance (ANCOVA) revealed no significant differences, except for the vigour subscale, which obtained a medium practical significant increase [Effect size (ES) = 0.65)] for the experimental compared to the control group when the pre-anaerobic and post-recovery changes in the STEMS subscale and energy index values between groups were compared. The dependent t-test and effect size results of the second study indicated that neither the experimental (CWT) nor the control group (PAR) experienced significant changes from pre-anaerobic to post-recovery time periods for any of the STEMS subscale or energy index values. However, the ANCOVA revealed that the experimental group showed a statistically significant higher value for the vigour subscale (p = 0.05) when compared to the control group. In addition, for vigour, the experimental group recorded a large practically significant higher value (ES = 0.92) for vigour as well as a large practically significant lower value for fatigue (ES = 0.88) compared to the control group. To the researchers‟ knowledge, this was the first study to compare the efficacy of CWI, CWT and PAR on the recovery of athletes‟ STEMS-derived mood states. Previous studies mainly focused on perceived fatigue, muscle soreness, Profile of Mood States- (POMS-) derived mood states and rate of perceived exertion (RPE) when investigating psychological recovery in athletes. However, despite the uniqueness of this study, results showed that when compared to PAR, CWI and CWT did not aid more in the acute psychological recovery of university-level rugby players‟ mood states. Vigour was the only mood state subscale for which both the CWI and CWT groups showed a practical or statistically significant higher value compared to the PAR group, while fatigue obtained a higher practical significant value for only CWT when compared to PAR. Therefore, although the study results support the use of CWI and CWT to alleviate vigour and fatigue post-exercise when compared to PAR, further research is required to gain understanding into the psychological mechanisms of both CWT and PAR, with an emphasis on knowledge and information in recovery of mood disturbances after exercise. / MSc (Sport Science), North-West University, Potchefstroom Campus, 2015
3

Acute effects of three recovery techniques on certain physical, motor performance and haematological components in university-level rugby players / Adele Broodryk

Broodryk, Adele January 2015 (has links)
Rugby has become a popular team sport worldwide with players training harder and competing more frequently, placing a great physiological demand on their bodies. To retain this performance level, players need to recover sufficiently between training and competitions. Two popular recovery techniques used are cold water immersion (CWI) and contrast water therapy (CWT). Despite numerous publications a lack still exists with regard to these specific recovery methods on physical and haematological parameters. Against this background, the main objectives of this study were firstly, to determine the effects of CWI compared to those of passive recovery (PAR) over a 48-hour period on physical and haematological parameters after an intense anaerobic exercise session in a cohort of male university-level rugby players. Secondly, to determine the effects of CWT compared to those of PAR over a 48-hour period on physical and haematological parameters after an intense anaerobic exercise session in a cohort of male university-level rugby players. Twenty-three rugby players of the North-West University participated in the study. The players were randomly assigned to either a control (n = 11; age: 20.1±0.3 y) or experimental (n = 12; age: 19.9±0.3 y) group. Participants reported to the laboratory where base line measurements were taken on certain physical (vertical jump test (VJT) height, VJT peak speed, VJT peak power and grip strength) and haematological (base excess (BEx), blood lactate (BLa-), calcium (Ca+), bicarbonate (HCO3), haemoglobin, haematocrit, pH level, partial oxygen level (PO2), partial carbon dioxide (PCO2), plasma glucose, potassium (K+), saturated oxygen (SO2), sodium (Na+) and total carbon dioxide (TCO2)) components. Thereafter participants were accompanied to the field to complete an intense anaerobic exercise session, followed by a recovery period of either CWI vs. PAR (week 1) or CWT vs. PAR (week 2). The recovery session comprised of either sitting passively in a still area (PAR), or immersion of CWI (8–10°C), or alternating immersions of five cycles between cold (1 min; 8–10°C) and warm water (3min; 40-42°C), totalling 20 minutes. Exactly three minutes, 24 and 48 hours after the recovery intervention all the measurements were re-taken to assess acute and longer-term effects of recovery. Descriptive statistics were followed by a linear mixed model analysis with an autoregressive 1 heterogeneous (AR1-Heterogeneous) structure, and between-group differences were examined using a one-way analysis of variance (ANOVA). Significance was set at p ≤0.05. Effect sizes were calculated to determine practical significance per recovery intervention as well as within groups. CWI indicated better recovery than PAR, with three out of the nine variables (BLa-, Na+ and haemoglobin) returning at 0 h post-recovery, and five (PO2, plasma glucose, VJT height, VJT peak power, VJT peak speed) only at 24 h post-CWI. In contrast, the PAR-group did not demonstrate recovery in any of the variables at 0 h post-PAR. However, an improvement was seen in VJT height across all time points. Four (BLa-, haemoglobin, VJT peak power and VJT peak speed) out of a possible nine variables recovered at 24 h with an additional two (PO2 and grip strength) variables showing recuperation at 48 h. A significant decrease (p ≤0.05) was seen in VJT height, PO2 and Na+ from post-anaerobic to immediately following either CWI or PAR (except for VJT height). Significant increases (p ≤0.05) were observed in VJT height, plasma glucose, and Na+ from 0 h post-recovery to 48 h post-recovery for both CWI and PAR. PO2 also significantly increased (p ≤0.05) from 0 h to 24 and 48 h post-CWI and for the PAR-group at 48 h. CWI tended to have a faster recovery rate than PAR over a 24-h period. The CWT vs. PAR showed the same trend, at 0-hours, six variables (BLa-, haemoglobin, VJT-height, VJT peak-power, VJT peak-speed and grip strength) was restored to base line, whereas plasma glucose recovered at 24-hours post-CWT. In addition, players’ jump and grip strength performance improved from base line. The PAR-group demonstrated recovery at 0 hours in four variables (BLa-, VJT height, VJT peak-speed and grip strength), and two variables (Na+ and haemoglobin) at 24-hours and plasma glucose at 48 hours. A significant decrease (p ≤0.05) was seen in haemoglobin and BLa- from post-anaerobic to either 24 or 48 hours for both groups. A significant increase in plasma glucose and PO2 from 0 to 24 hours was observed in both groups. No significant intergroup change in physical components was noticed. However, intergroup results indicated CWT to be superior to PAR with statistical significance observed in BLa- and grip strength (p ≤0.05) at various time points. The conclusion drawn from the above-mentioned results is that a recovery session comprising either 20-minutes of CWI or CWT may lead to significantly better physical components and restoration of haematological components in university-level rugby players compared to that of passive recovery. However, a detrimental effect was noticed in some components over the recovery period. / MA (Sport Science), North-West University, Potchefstroom Campus, 2015
4

A comparison between the acute effects of different recovery techniques on the mood states of university-level rugby players / Erika van der Bijl

Van der Bijl, Erika January 2014 (has links)
Rugby union training and match-play are physiologically and psychologically very demanding and the execution of post-exercise recovery techniques in players‟ training regimes are therefore necessary to aid in the physiological and psychological restoration of athletes‟ training and performance abilities. However, despite numerous research findings with regard to the efficiency of especially cold water immersion (CWI), contrast water therapy (CWT) and passive recovery (PAR) on the physiological recovery of athletes post-exercise, only a limited number of researchers have examined the possible benefits of these recovery techniques on the psychological recovery of athletes. Consequently, the objectives of this study were firstly to determine the difference between the acute effects of CWI and PAR on the mood states (anger, confusion, depression, fatigue, tension and vigour) and the energy index of university-level rugby players post-exercise, and secondly to determine the difference between the acute effects of CWT and PAR on the mood states and the energy index of university-level rugby players post-exercise. Twenty-three under/21 university-level rugby players (age 20.1 ± 0.41) of a South African university club voluntarily participated in this study. The players were randomly divided into a control group (PAR) and an experimental group (CWI or CWT). Participants completed the Stellenbosch Mood Scale (STEMS) questionnaire over four time periods: during the morning (baseline); before completion of a high-intensity anaerobic training session (pre-anaerobic); after completion of a high-intensity anaerobic training session of 15 minutes (post-anaerobic) and after completion of a 20-minute recovery session (post-recovery). Blood lactate measurements were also taken 3 minutes after completion of the anaerobic session. To test the first objective, the experimental group completed 20 minutes of CWI, whereas the control group recovered passively for the same time period. For the purpose of the second objective, the experimental group completed 20 minutes of CWT, whereas the control group recovered passively for the same time period. Although the dependent t-test and effect size results of the first study showed that the experimental group (CWI) experienced no significant changes from the pre-anaerobic to post-recovery time periods for any of the STEMS subscale values or the energy index, the control group‟s (PAR) confusion, depression and tension subscale values decreased significantly (p < 0.05) from the pre-anaerobic to the post-recovery time periods. Despite these changes, the one-way between groups‟ analysis of covariance (ANCOVA) revealed no significant differences, except for the vigour subscale, which obtained a medium practical significant increase [Effect size (ES) = 0.65)] for the experimental compared to the control group when the pre-anaerobic and post-recovery changes in the STEMS subscale and energy index values between groups were compared. The dependent t-test and effect size results of the second study indicated that neither the experimental (CWT) nor the control group (PAR) experienced significant changes from pre-anaerobic to post-recovery time periods for any of the STEMS subscale or energy index values. However, the ANCOVA revealed that the experimental group showed a statistically significant higher value for the vigour subscale (p = 0.05) when compared to the control group. In addition, for vigour, the experimental group recorded a large practically significant higher value (ES = 0.92) for vigour as well as a large practically significant lower value for fatigue (ES = 0.88) compared to the control group. To the researchers‟ knowledge, this was the first study to compare the efficacy of CWI, CWT and PAR on the recovery of athletes‟ STEMS-derived mood states. Previous studies mainly focused on perceived fatigue, muscle soreness, Profile of Mood States- (POMS-) derived mood states and rate of perceived exertion (RPE) when investigating psychological recovery in athletes. However, despite the uniqueness of this study, results showed that when compared to PAR, CWI and CWT did not aid more in the acute psychological recovery of university-level rugby players‟ mood states. Vigour was the only mood state subscale for which both the CWI and CWT groups showed a practical or statistically significant higher value compared to the PAR group, while fatigue obtained a higher practical significant value for only CWT when compared to PAR. Therefore, although the study results support the use of CWI and CWT to alleviate vigour and fatigue post-exercise when compared to PAR, further research is required to gain understanding into the psychological mechanisms of both CWT and PAR, with an emphasis on knowledge and information in recovery of mood disturbances after exercise. / MSc (Sport Science), North-West University, Potchefstroom Campus, 2015
5

Vliv teploty vody na rychlost zotavení při opakovaném izometrickém výkonu / Effect of water temperature on the recovery during repeated isometric performance

Škoda, Jan January 2015 (has links)
Title: The influence of water temperature on the rate of recovery during repeated isometric exercise. Objectives: The aim of this thesis is to assess the effect of water temperature on immersion of forearm to water for the sake of speeding up the recovery process during repeated isometric performance. Methods: Five male subjects from the students of FTVS (average age 22 ± 3 years) underwent three meaurements with repeated exercise to exhaustion with various kinds of rest periods. The exercise was represented by three series of intermittent isometric contraction of the finger flexors until exhaustion with 20 minutes rest period. The rest period was represented by the immersion of forearm into cold water (8řC; 15řC;) as well as by a passive rest. Sturation O2 of saturated hemoglobin (SmO2) was monitored by the spectrometer throughout the entire measurements at flexor digitorum profundus. Results: The reliability of measurements was rel=0,79 with standard deviation SD= 27,3s and standard measurement error SEM= 12,5s. The least effective method of recovery was passive recovery. Decrease in the time between the first, second and third contraction respectively was 35s, 34s respectively. Immersion in 15 ř C water under recovery phase led to improvement in the second contraction by 43s and by 27s in the...
6

Post-Exercise Responses During Treatment Delays do not Affect the Physiological Responses to Cooling in Cold Water in Hyperthermic Individuals

Carlson, Mark 09 August 2013 (has links)
Victims of exertional heat stroke (EHS) in whom treatment is delayed have higher rates of multi-organ failure and a greater number of fatalities. Death related to EHS is preventable, through immediate treatment via cold-water immersion (CWI). To date little is known about the influence of treatment delays on core cooling following EHS. Thus we sought to examine the effects of treatment delays on cardiovascular and thermal responses prior to, during, and following CWI treatment in individuals with exercise-induced hyperthermia. Our findings demonstrate that treatment delays resulted in a sustained level of hyperthermia and cardiovascular strain that significantly increased the time an individual is at risk to the potential lethal effects of EHS. Moreover, we report that cold water immersion treatment is powerful enough to overcome the adverse effects of treatment delays and rapidly reduce core temperatures while facilitating the re-establishment of blood pressure towards normal resting levels.
7

Whole-Body Cooling Following Exercise-Induced Hyperthermia: Biophysical Considerations

Friesen, Brian J. 28 January 2014 (has links)
This thesis examined the effect of differences in body surface area-to-lean body mass ratio (AD/LBM) on core temperature cooling rates during cold water immersion (2°C, CWI) and temperate water immersion (26°C, TWI) following exercise-induced hyperthermia (end-exercise rectal temperature of 40°C). Individuals with a High AD/LBM (315 cm2/kg) had a ~1.7-fold greater overall rectal cooling rate relative to those with Low AD/LBM (275 cm2/kg) during both CWI and TWI. Further, overall rectal cooling rates during CWI were ~2.7-fold greater than during TWI for both the High and Low AD/LBM groups. Study findings show that AD/LBM must be considered when determining the duration of the immersion period. However, CWI provides the most effective cooling treatment for EHS patients irrespective of physical differences between individuals.
8

Efekt teploty vody během zotavení studenou vodou na opakovaný izometrický výkon / Effect of water temperature during cold water immersion on repeated isometric performance

Krupková, Dominika January 2018 (has links)
Title: Effect of water temperature during cold water immersion on repeated isometric performance Objectives: The aim of the study was to evaluate the effect of water temperature on recovery using repeated isometric performance of finger flexors to exhaustion Methods: The study was attended by a group of climbers consisting of 16 men (aged 30.8 ± 7.2 years) and 18 women (aged 26.7 ± 4.5 years). Participants came 3 times in the laboratory, where repeated intermittent isometric performance until exhaustion with different recovery strategy (passive recovery, immersion of forearm to 8ř C water - CWI 8, immersion of forearm to 15ř C water - CWI 15) were completed Results: The results were evaluated according time of contraction and force- time-integral (FTI). After passive recovery, the second time of contraction dropped by ↓ 9% and the third contraction by 20% compared to the first one. In response to cold water (CWI), after CWI 8 second time of contraction increased by ↑ 32% and CWI 15 by ↑ 36% compared to the first one. The third time of contraction was worse for CWI 8 by ↓ 4%, and CWI 15 was better by ↑ 26% compared to the first contraction. Conclusion: Cold water immersion is an effective recovery method between intermittent isometric performance compared to passive recovery strategy. CWI 15 is more...
9

Post-Exercise Responses During Treatment Delays do not Affect the Physiological Responses to Cooling in Cold Water in Hyperthermic Individuals

Carlson, Mark January 2013 (has links)
Victims of exertional heat stroke (EHS) in whom treatment is delayed have higher rates of multi-organ failure and a greater number of fatalities. Death related to EHS is preventable, through immediate treatment via cold-water immersion (CWI). To date little is known about the influence of treatment delays on core cooling following EHS. Thus we sought to examine the effects of treatment delays on cardiovascular and thermal responses prior to, during, and following CWI treatment in individuals with exercise-induced hyperthermia. Our findings demonstrate that treatment delays resulted in a sustained level of hyperthermia and cardiovascular strain that significantly increased the time an individual is at risk to the potential lethal effects of EHS. Moreover, we report that cold water immersion treatment is powerful enough to overcome the adverse effects of treatment delays and rapidly reduce core temperatures while facilitating the re-establishment of blood pressure towards normal resting levels.
10

Whole-Body Cooling Following Exercise-Induced Hyperthermia: Biophysical Considerations

Friesen, Brian J. January 2014 (has links)
This thesis examined the effect of differences in body surface area-to-lean body mass ratio (AD/LBM) on core temperature cooling rates during cold water immersion (2°C, CWI) and temperate water immersion (26°C, TWI) following exercise-induced hyperthermia (end-exercise rectal temperature of 40°C). Individuals with a High AD/LBM (315 cm2/kg) had a ~1.7-fold greater overall rectal cooling rate relative to those with Low AD/LBM (275 cm2/kg) during both CWI and TWI. Further, overall rectal cooling rates during CWI were ~2.7-fold greater than during TWI for both the High and Low AD/LBM groups. Study findings show that AD/LBM must be considered when determining the duration of the immersion period. However, CWI provides the most effective cooling treatment for EHS patients irrespective of physical differences between individuals.

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