There is some evidence to suggest that oxygen consumption (VO2) and oxygen delivery to muscle are reduced at exercise onset and steady state in individuals with type 2 diabetes (T2D), although no studies have combined measurements of both muscle blood flow and VO2 during exercise in this population. OBJECTIVES: 1) To determine whether a reduction in VO2 during exercise would be accompanied by reduced leg blood flow (LBF). 2) To examine the dynamic response characteristics of LBF to determine whether feedforward and/or feedback control systems of blood flow regulation are impaired. METHODS: Four men with T2D and six healthy, activity matched controls (CON) performed supine, two-leg knee extension/flexion exercise tests involving progressive increase in exercise intensity to exhaustion and step increases to a low intensity equivalent to lifting 7.5 kg (LO7.5kg), and a moderate intensity equivalent to 90% of ventilatory threshold (VT90%). MEASUREMENTS: LBF, VO2, mean arterial pressure, heart rate, and stroke volume were measured continuously. RESULTS: Means ± SE, CON vs. T2D. 1) ∆VO2 was not different between groups during the incremental test (P= 0.264), ∆LBF in T2D tended to be lower (P = 0.098). 2) ∆VO2 was not different between groups at any time during LO7.5kg (P = 0.351). Individuals with T2D demonstrated a lower ∆LBF at time = 15 s (3435.6 ± 275.0 vs. 2120.4 ± 218.4 ml/min, P = 0.018). 3) Gains for baseline (G0) and phase I (G1) LBF adaptation to LO7.5kg were lower in T2D compared to CON (G0: 959.8 ± 111.3 vs. 617.0 ± 22.1 ml/min, P = 0.044; G1: 3662.1 ± 229.0 vs. 2128.1 ± 161.6 ml/min, P = 0.002). 4) The time required to achieve 63% of the total response magnitude tended to be slower in T2D (LO7.5kg: 14.3 ± 1.7 vs. 23.1 ± 4.2 s; VT90%: 26.2 ± 3.5 vs. 40.0 ± 7.5 s; P = 0.095). CONCLUSIONS: 1) The initiatory rise in LBF is significantly lower in individuals with T2D, likely due to impairments in feedforward control mechanisms of blood flow regulation, 2) Individuals with T2D do not demonstrate lower VO2 responses to exercise despite an impaired LBF response. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2009-10-09 17:52:31.708

Access to abstract is permanently restricted to Ball State communtiy only. / Access to thesis permanently restricted to Ball State community only / School of Physical Education, Sport, and Exercise Science

Priming exercise, or the ‘warm-up’, is an accepted practice prior to exercise participation, physical training or sporting competition. Traditionally, low intensity exercise has been used prior to both short- and long-duration events in an effort to prepare the athlete, but not fatigue them. Recently, however, a more scientific approach to priming exercise has been considered important, with some research suggesting that a high intensity intermittent priming strategy may be optimal. However, given the paucity of performance focussed ‘warm-up’ studies, and that existing data regarding high-intensity priming strategies is inconclusive, the aim of this thesis was to determine the effects of three high-intensity intermittent priming strategies on physiological responses and subsequent 3km laboratory time-trial (TT) performance. Ten well-conditioned endurance-trained male cyclists (mean ± SD: age, 28.3 ± 8.4 yr, body mass, 81.8 ± 11.6 kg, stature, 1.8 ± 0.1 m, O2peak, 4.6 ± 0.5 L•min−1) were recruited for this study. After an initial incremental exercise test to exhaustion, participants completed four 3km time trials (TT) on four separate occasions, each preceded by a different priming strategy. These included a ‘self-selected’ (control) condition, and three high-intensity intermittent priming strategies of varying intensity (100% and 150% of the power at O2peak, and all-out) and fixed duration (15 minutes), each in predetermined random order. Five minutes passive rest separated each priming exercise condition from the experimental 3km-TT. Oxygen uptake ( O2) and heart rate (HR) were measured continuously, while blood lactate concentration ([BLa]) and core temperature (TC) were recorded at rest, post-priming exercise, and immediately prior to and following the 3km-TT. In an attempt to provide a mechanistic explanation for changes in performance, O2 kinetic variables were determined from the O2 data. Performance was quantified as a mean power (Wmean) and total time taken to complete the 3km-TT. Mean power output and time taken for each 500m segment of the 3km-TT were also calculated. Results demonstrated that the athletes self-chosen priming condition (378.6 ± 44.0 W) resulted in Wmean that was slightly greater than both the lowest (376.3 ± 44.9 W; 0.7%; p = 0.57) and moderate (373.9 ± 47.8 W; 1.5%, p = 0.30) intensity intermittent priming condition, but significantly greater than the ‘all-out’ intermittent sprint priming condition (357.4 ± 44.5 W; 5.8%, p = 0.0033). Similar differences were observed for time. While differences existed in the O2 deficit (however, mainly non-significant), these differences did not provide clear explanations for the differences in performance, with the moderate priming condition displaying a significantly reduced O2 deficit (59.4 ± 15.6 L, p < 0.05), despite the non-significant change in Wmean, compared to the self-chosen priming condition (73.3 ± 18.6 L). Additionally no significant differences were observed in either the time constant or the mean response time of O2. Significant findings with regard to HR, [BLa] and TC were observed, but consistent with O2 kinetic variables, they were not related to, nor explain performance changes. In conclusion, regardless of intensity, different high-intensity intermittent priming exercise did not improve 3km-TT performance more than the control condition (self-chosen). A priming strategy that is overly intense was detrimental to subsequent cycling performance. The observed finding that a self-chosen priming strategy resulted in a comparable performance suggests that athletes are able to self-select (consciously or sub-consciously) a ‘warm-up’ that is of appropriate intensity/duration. Further work utilising the priming strategies from the current study with events of shorter duration is required to further clarify how priming strategies of this nature may affect track cycling performance.

O polo aquático (PA) é um esporte coletivo e de invasão praticado no meio líquido. Dentre as técnicas utilizadas pelos jogadores de PA, destaca-se o eggbeater (EB), movimento propulsivo de membros inferiores que permite ao jogador a permanência na posição vertical e deslocamentos. Devido às especificidades do gesto de EB e à falta de informações a respeito das características fisiológicas de jogadores de PA, o objetivo deste estudo foi comparar e verificar a concordância de resultados obtidos de testes de esforço máximo realizados dentro (com EB) e fora da água (em cicloergômetro). Para tal, doze jogadores de PA (30,5 ± 7,7 anos de idade; 79,2 ± 7,2 kg de massa corporal; 179,1 ± 5,9 cm de estatura) foram avaliados em duas etapas: (1) em laboratório com teste máximo em ciclo-ergômetro e (2) em piscina com teste máximo em EB. Em ambas as etapas foram obtidos: consumo máximo de oxigênio (VO2max), taxa de troca gasosa (RER), frequência cardíaca máxima (FCmax) e esforço percebido (EP). Entre os dados obtidos de ambos os testes foram realizadas análises descritivas, análises de comparação, correlação intra-classe e concordância. Não foram encontradas diferenças entre os valores máximos obtidos nos dois testes (ciclo-ergômetro: VO2max = 40,2 ± 2,7 ml.kg-1.min-1, RER = 1,17 ± 0,08, FCmax = 181,4 ± 11,7 bpm; EP = 20; eggbeater: VO2max = 38,4 ± 5,7 ml.kg- 1.min-1, RER = 1,19 ± ,12, FCmax = 179 ± 11,7 bpm; EP = 20). De modo geral, os valores encontrados no teste em EB apresentaram maior variabilidade, porém análises de Bland-Altmann indicam limites de concordância aceitáveis para VO2max, RER e FCmax obtidos de diferentes métodos (dentro e fora da água) entre jogadores de PA. / Water polo (PA) is a team and invasion sport performed in water. Among the techniques used by the players, the eggbeater kick (EB) is a propulsive movement of the lower limbs, which allows the player to remain in the upright position and to displace. Due to the specifics of the EB and the lack of information about the physiological characteristics of PA players, the aim of this study was to compare and to verify the agreement of maximal exercise tests in (EB) and out (cycling) water. Twelve PA players (30.5 ± 7.7 years, 79.2 ± 7.2 kg body mass; 179.1 ± 5.9 cm height) were evaluated in two steps: (1) in laboratory with maximal test on a cycle ergometer and (2) in pool with maximum test in EB. In both phases, maximal oxygen uptake (VO2max), gas exchange ratio (RER), maximal heart rate (HRmax) and perceived exertion (EP) were obtained. The descriptive analysis, comparison analysis, intra-class correlation and level of agreement were performed. No differences were found between the maximum values obtained in the two tests (cycle ergometer: VO2max = 40.2 ± 2.7 ml.kg-1.min-1, RER = 1.17 ± 0.08, FCmax = 181.4 ± 11.7 bpm; EP = 20; eggbeater: VO2max = 38.4 ± 5.7 ml.kg-1.min-1, RER = 1.19 ± 12 water, FCmax = 179 ± 11.7 bpm; EP = 20). In general, the values in EB test showed greater variability than in cycle ergometer, but the Bland-Altmann analyzes indicate acceptable limits of agreement for VO2max, RER and HRmax obtained from different methods (in and out water) in PA players.

O polo aquático (PA) é um esporte coletivo e de invasão praticado no meio líquido. Dentre as técnicas utilizadas pelos jogadores de PA, destaca-se o eggbeater (EB), movimento propulsivo de membros inferiores que permite ao jogador a permanência na posição vertical e deslocamentos. Devido às especificidades do gesto de EB e à falta de informações a respeito das características fisiológicas de jogadores de PA, o objetivo deste estudo foi comparar e verificar a concordância de resultados obtidos de testes de esforço máximo realizados dentro (com EB) e fora da água (em cicloergômetro). Para tal, doze jogadores de PA (30,5 ± 7,7 anos de idade; 79,2 ± 7,2 kg de massa corporal; 179,1 ± 5,9 cm de estatura) foram avaliados em duas etapas: (1) em laboratório com teste máximo em ciclo-ergômetro e (2) em piscina com teste máximo em EB. Em ambas as etapas foram obtidos: consumo máximo de oxigênio (VO2max), taxa de troca gasosa (RER), frequência cardíaca máxima (FCmax) e esforço percebido (EP). Entre os dados obtidos de ambos os testes foram realizadas análises descritivas, análises de comparação, correlação intra-classe e concordância. Não foram encontradas diferenças entre os valores máximos obtidos nos dois testes (ciclo-ergômetro: VO2max = 40,2 ± 2,7 ml.kg-1.min-1, RER = 1,17 ± 0,08, FCmax = 181,4 ± 11,7 bpm; EP = 20; eggbeater: VO2max = 38,4 ± 5,7 ml.kg- 1.min-1, RER = 1,19 ± ,12, FCmax = 179 ± 11,7 bpm; EP = 20). De modo geral, os valores encontrados no teste em EB apresentaram maior variabilidade, porém análises de Bland-Altmann indicam limites de concordância aceitáveis para VO2max, RER e FCmax obtidos de diferentes métodos (dentro e fora da água) entre jogadores de PA. / Water polo (PA) is a team and invasion sport performed in water. Among the techniques used by the players, the eggbeater kick (EB) is a propulsive movement of the lower limbs, which allows the player to remain in the upright position and to displace. Due to the specifics of the EB and the lack of information about the physiological characteristics of PA players, the aim of this study was to compare and to verify the agreement of maximal exercise tests in (EB) and out (cycling) water. Twelve PA players (30.5 ± 7.7 years, 79.2 ± 7.2 kg body mass; 179.1 ± 5.9 cm height) were evaluated in two steps: (1) in laboratory with maximal test on a cycle ergometer and (2) in pool with maximum test in EB. In both phases, maximal oxygen uptake (VO2max), gas exchange ratio (RER), maximal heart rate (HRmax) and perceived exertion (EP) were obtained. The descriptive analysis, comparison analysis, intra-class correlation and level of agreement were performed. No differences were found between the maximum values obtained in the two tests (cycle ergometer: VO2max = 40.2 ± 2.7 ml.kg-1.min-1, RER = 1.17 ± 0.08, FCmax = 181.4 ± 11.7 bpm; EP = 20; eggbeater: VO2max = 38.4 ± 5.7 ml.kg-1.min-1, RER = 1.19 ± 12 water, FCmax = 179 ± 11.7 bpm; EP = 20). In general, the values in EB test showed greater variability than in cycle ergometer, but the Bland-Altmann analyzes indicate acceptable limits of agreement for VO2max, RER and HRmax obtained from different methods (in and out water) in PA players.

Made available in DSpace on 2014-06-11T19:29:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-29Bitstream added on 2014-06-13T18:59:09Z : No. of bitstreams: 1 nogueira_cz_me_botfm.pdf: 406786 bytes, checksum: 4f06b152f2b5c1591b14b7babbb4bef6 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O condicionamento aeróbio está associado à redução de níveis pressóricos e outros fatores de risco cardiovascular em hipertensos. A relação entre FC e VO2 durante o exercício progressivo é utilizada para prescrição do exercício físico. O objetivo deste ensaio clínico é investigar os efeitos de um programa de treinamento aeróbio supervisionado de 14 semanas sobre o condicionamento aeróbio e a relação FCVO2, com intuito de avaliar a prescrição inicial baseada na FC. Hipertensos não medicados sedentários, n=55, PAS/PAD(24hs)= 141±11/90±9 mmHg, idade= 49±9 anos, foram submetidos ao treinamento físico aeróbio (esteira elétrica, 50- 70%VO2máx, 3-5 sessões/sem, 45 min/sessão) e avaliados pré e pós treinamento por teste ergoespirométrico. Após 3 meses de exercício, o treinamento aeróbio promoveu um aumento de 7% no VO2máx e 10% no tempo de permanência no teste ergoespirométrico (p<0,0001). O condicionamento aeróbio obtido com o treinamento diminuiu significativamente a FC na mesma intensidade absoluta e não modificou a FC entre 50 e 70%VO2máx e a relação FC-VO2. A resposta do VO2máx ao treinamento aeróbio é variável e depende das características individuais. Assim, o grupo de hipertensos foi dividido em tercis, de acordo com o aumento no VO2máx e comparado o subgrupo do tercil inferior (n=20, ΔVO2máx= 0,2±0,6 ml/kg/min) com o subgrupo do tercil superior (n=19, ΔVO2máx= 4,0±1,1 ml/kg/min). O subgrupo “alto respondedor” apresentou redução significativa na FC para o mesmo VO2. Assim, uma vez determinada a relação FC-VO2 do indivíduo, a mesma faixa de FC pode ser utilizada como estimativa da intensidade de exercício ao longo de um programa de treinamento físico aeróbio. Realizar o teste incremental não é necessário para ajustar a prescrição do exercício em hipertensos após 14 semanas de treinamento aeróbio... / The aerobic conditioning is associated with the reduction of blood pressure levels and with other cardiovascular risk factors in hypertensive subjects. The relationship between heart rate (HR) and oxygen uptake (VO2) during the progressive exercise is used to prescribe the exercise program. The present clinical study is aimed at examining the effects of a 14-week supervised aerobic training program on the aerobic conditioning and the HR/VO2 relationship, to evaluate the initial prescription based on the HR. Sedentary hypertensive people that are not medicated, n = 55, SBP/DBP (24 hours) = 141 ± 11/90 ± 9 mmHg, age = 49 ± 9 years, were subjected to the aerobic physical training (electrical treadmill, 50-70%VO2max, 3-5 sessions/week, 45 minutes/session) and evaluated by means of ergospirometric tests before and after the training. After 3 months of exercises, the aerobic training promoted an increase of 7% in VO2max and of 10% in the permanence time in the ergospirometric test (p < 0.0001). The aerobic conditioning obtained with the training lowered the HR significantly in the same absolute intensity and did not modify the HR between 50 and 70%VO2max and the HR-VO2 relationship. The VO2max response to aerobic training is variable and it depends on individual characteristics. Therefore, the group of hypertensive subjects was divided in tertiles according to the increase in VO2max, and the low tertile (n = 20, ΔVO2max = 0.2 ± 0.6 ml/kg/min) was compared with the high tertile (n = 19, ΔVO2max = 4.0 ± 1.1 ml/kg/min). The “high responder” subgroup presented a significant reduction in the HR for the same VO2. Therefore, since the subject’s HR-VO2 relationship is linear, the same HR can be used as an estimate of the exercise intensity during an aerobic physical training program. It would be not necessary to perform a new incremental test to adjust the exercise prescription for hypertensive subjects after 14 weeks of aerobic training.

Orientador: Roberto Carlos Burini / Banca: Paulo Henrique Waib / Banca: Maria Urbana Pinto Brandão Rondon / Resumo: O condicionamento aeróbio está associado à redução de níveis pressóricos e outros fatores de risco cardiovascular em hipertensos. A relação entre FC e VO2 durante o exercício progressivo é utilizada para prescrição do exercício físico. O objetivo deste ensaio clínico é investigar os efeitos de um programa de treinamento aeróbio supervisionado de 14 semanas sobre o condicionamento aeróbio e a relação FCVO2, com intuito de avaliar a prescrição inicial baseada na FC. Hipertensos não medicados sedentários, n=55, PAS/PAD(24hs)= 141±11/90±9 mmHg, idade= 49±9 anos, foram submetidos ao treinamento físico aeróbio (esteira elétrica, 50- 70%VO2máx, 3-5 sessões/sem, 45 min/sessão) e avaliados pré e pós treinamento por teste ergoespirométrico. Após 3 meses de exercício, o treinamento aeróbio promoveu um aumento de 7% no VO2máx e 10% no tempo de permanência no teste ergoespirométrico (p<0,0001). O condicionamento aeróbio obtido com o treinamento diminuiu significativamente a FC na mesma intensidade absoluta e não modificou a FC entre 50 e 70%VO2máx e a relação FC-VO2. A resposta do VO2máx ao treinamento aeróbio é variável e depende das características individuais. Assim, o grupo de hipertensos foi dividido em tercis, de acordo com o aumento no VO2máx e comparado o subgrupo do tercil inferior (n=20, ΔVO2máx= 0,2±0,6 ml/kg/min) com o subgrupo do tercil superior (n=19, ΔVO2máx= 4,0±1,1 ml/kg/min). O subgrupo "alto respondedor" apresentou redução significativa na FC para o mesmo VO2. Assim, uma vez determinada a relação FC-VO2 do indivíduo, a mesma faixa de FC pode ser utilizada como estimativa da intensidade de exercício ao longo de um programa de treinamento físico aeróbio. Realizar o teste incremental não é necessário para ajustar a prescrição do exercício em hipertensos após 14 semanas de treinamento aeróbio... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aerobic conditioning is associated with the reduction of blood pressure levels and with other cardiovascular risk factors in hypertensive subjects. The relationship between heart rate (HR) and oxygen uptake (VO2) during the progressive exercise is used to prescribe the exercise program. The present clinical study is aimed at examining the effects of a 14-week supervised aerobic training program on the aerobic conditioning and the HR/VO2 relationship, to evaluate the initial prescription based on the HR. Sedentary hypertensive people that are not medicated, n = 55, SBP/DBP (24 hours) = 141 ± 11/90 ± 9 mmHg, age = 49 ± 9 years, were subjected to the aerobic physical training (electrical treadmill, 50-70%VO2max, 3-5 sessions/week, 45 minutes/session) and evaluated by means of ergospirometric tests before and after the training. After 3 months of exercises, the aerobic training promoted an increase of 7% in VO2max and of 10% in the permanence time in the ergospirometric test (p < 0.0001). The aerobic conditioning obtained with the training lowered the HR significantly in the same absolute intensity and did not modify the HR between 50 and 70%VO2max and the HR-VO2 relationship. The VO2max response to aerobic training is variable and it depends on individual characteristics. Therefore, the group of hypertensive subjects was divided in tertiles according to the increase in VO2max, and the low tertile (n = 20, ΔVO2max = 0.2 ± 0.6 ml/kg/min) was compared with the high tertile (n = 19, ΔVO2max = 4.0 ± 1.1 ml/kg/min). The "high responder" subgroup presented a significant reduction in the HR for the same VO2. Therefore, since the subject's HR-VO2 relationship is linear, the same HR can be used as an estimate of the exercise intensity during an aerobic physical training program. It would be not necessary to perform a new incremental test to adjust the exercise prescription for hypertensive subjects after 14 weeks of aerobic training. / Mestre

O polo aquático (PA) é um esporte coletivo e de invasão praticado no meio líquido. Dentre as técnicas utilizadas pelos jogadores de PA, destaca-se o eggbeater (EB), movimento propulsivo de membros inferiores que permite ao jogador a permanência na posição vertical e deslocamentos. Devido às especificidades do gesto de EB e à falta de informações a respeito das características fisiológicas de jogadores de PA, o objetivo deste estudo foi comparar e verificar a concordância de resultados obtidos de testes de esforço máximo realizados dentro (com EB) e fora da água (em cicloergômetro). Para tal, doze jogadores de PA (30,5 ± 7,7 anos de idade; 79,2 ± 7,2 kg de massa corporal; 179,1 ± 5,9 cm de estatura) foram avaliados em duas etapas: (1) em laboratório com teste máximo em ciclo-ergômetro e (2) em piscina com teste máximo em EB. Em ambas as etapas foram obtidos: consumo máximo de oxigênio (VO2max), taxa de troca gasosa (RER), frequência cardíaca máxima (FCmax) e esforço percebido (EP). Entre os dados obtidos de ambos os testes foram realizadas análises descritivas, análises de comparação, correlação intra-classe e concordância. Não foram encontradas diferenças entre os valores máximos obtidos nos dois testes (ciclo-ergômetro: VO2max = 40,2 ± 2,7 ml.kg-1.min-1, RER = 1,17 ± 0,08, FCmax = 181,4 ± 11,7 bpm; EP = 20; eggbeater: VO2max = 38,4 ± 5,7 ml.kg- 1.min-1, RER = 1,19 ± ,12, FCmax = 179 ± 11,7 bpm; EP = 20). De modo geral, os valores encontrados no teste em EB apresentaram maior variabilidade, porém análises de Bland-Altmann indicam limites de concordância aceitáveis para VO2max, RER e FCmax obtidos de diferentes métodos (dentro e fora da água) entre jogadores de PA. / Water polo (PA) is a team and invasion sport performed in water. Among the techniques used by the players, the eggbeater kick (EB) is a propulsive movement of the lower limbs, which allows the player to remain in the upright position and to displace. Due to the specifics of the EB and the lack of information about the physiological characteristics of PA players, the aim of this study was to compare and to verify the agreement of maximal exercise tests in (EB) and out (cycling) water. Twelve PA players (30.5 ± 7.7 years, 79.2 ± 7.2 kg body mass; 179.1 ± 5.9 cm height) were evaluated in two steps: (1) in laboratory with maximal test on a cycle ergometer and (2) in pool with maximum test in EB. In both phases, maximal oxygen uptake (VO2max), gas exchange ratio (RER), maximal heart rate (HRmax) and perceived exertion (EP) were obtained. The descriptive analysis, comparison analysis, intra-class correlation and level of agreement were performed. No differences were found between the maximum values obtained in the two tests (cycle ergometer: VO2max = 40.2 ± 2.7 ml.kg-1.min-1, RER = 1.17 ± 0.08, FCmax = 181.4 ± 11.7 bpm; EP = 20; eggbeater: VO2max = 38.4 ± 5.7 ml.kg-1.min-1, RER = 1.19 ± 12 water, FCmax = 179 ± 11.7 bpm; EP = 20). In general, the values in EB test showed greater variability than in cycle ergometer, but the Bland-Altmann analyzes indicate acceptable limits of agreement for VO2max, RER and HRmax obtained from different methods (in and out water) in PA players.

Background: During incremental exercise, systolic blood pressure (SBP) increases due to increasing cardiac output. However, the impact of workload on SBP has often been overlooked. Indexing the increase in SBP to the increase in workload could provide a way of accounting for this. Athletes often reach higher maximal SBP (SBPmax) than untrained subjects, which has been attributed to their superior cardiac capacity. How this affects the relation between SBP and workload is not established. Aim: We sought to characterise the novel metrics SBP/VO2-slope and SBP/Watt-slope in endurance athletes and to analyse possible correlations between these metrics and maximal oxygen uptake (VO2max) in a population of endurance athletes and healthy, non-athletic subjects. We also sought to compare the SBP response of athletes to values predicted by newly published reference equations accounting for workload. Methods: In 24 endurance athletes and 5 healthy non-athletes we assessed the workload-indexed blood pressure response during a graded bicycle ergometer test. SBPmax was defined as the last SBP during exercise, VO2max as the mean of the two highest consecutive VO2 measurements at end of exercise. Results: The mean SBP/VO2-slope was 31.1 ± 9.7 mmHg/l/min and the mean SBP/Watt-slope was 0.28 ± 0.08 mmHg/Watt. We found no significant correlation between VO2max and the SBP/VO2-slope or the SBP/Watt-slope, nor with SBP at 50 W or at 200 W. In males there was a significant correlation between VO2max and SBPmax. The endurance athletes had less steep SBP/Watt-slopes and higher SBPmax than predicted by reference equations.  Conclusion: The SBP/VO2-slope offers a precise way of indexing blood pressure to workload and could provide a valuable tool in future studies investigating the SBP response to exercise. Our results suggest that different reference equations than in the general population might be needed when evaluating the SBP response in athletes.

The purpose of this study was to evaluate increased cardiac output (Q) on oxygen kinetics at exercise intensities above and below the lactate threshold (LT). We hypothesized the increase in Q using head-out water immersion (HOI) while treadmill running would reduce the rate constant of the fast component and reduce the amplitude of the slow component of oxygen kinetics compared with land treadmill running. Subjects (n=10) performed two 6 min exercise bouts at a 15% below and above the LT on a land and underwater treadmill following rest. A single exponential equation [VO2(t) = VO2(b) + A1•(1-e-t/TC1] was used to evaluate VO2. The slow component at the end of exercise was estimated by subtracting (VO2(b) + A1) from the plateau. The mean LT for HOI running 1.80 ± .09 L • min-1 was significantly lower (p < 0.05) than 2.15 ± 1.03 L • min-1 while running on the land. The Q during HOI exercise below and above the LT (16.5 ± 0.6 L • min-1, 18.0 ± 1.2 L • min-1) was significantly higher (p < 0.05) than the Q during exercise below and above the LT on land (11.5 ± 0.8 L • min-1, 13.0 ± 0.7 L • min-1). During HOI exercise below LT time to reach steady-state was delayed (8 ± 2 s). Exercise above LT showed similar phase one time constants for all exercise trials. The amplitude of the slow component was not influenced by HOI. As such, the increase in during HOI exercise did not hastening uptake kinetics.