Acute exercise performed close to the anaerobic threshold improves cognitive performance in elderly females

The objective of the present study was to compare the effect of acute exercise performed at different intensities in relation to the anaerobic threshold (AT) on abilities requiring control of executive functions or alertness in physically active elderly females. Forty-eight physically active elderly females (63.8 ± 4.6 years old) were assigned to one of four groups by drawing lots: control group without exercise or trial groups with exercise performed at 60, 90, or 110 percent of AT (watts) and submitted to 5 cognitive tests before and after exercise. Following cognitive pretesting, an incremental cycle ergometer test was conducted to determine AT using a fixed blood lactate concentration of 3.5 mmol/L as cutoff. Acute exercise executed at 90 percent of AT resulted in significant (P < 0.05, ANOVA) improvement in the performance of executive functions when compared to control in 3 of 5 tests (verbal fluency, Tower of Hanoi test (number of movements), and Trail Making test B). Exercising at 60 percent of AT did not improve results of any tests for executive functions, whereas exercise executed at 110 percent of AT only improved the performance in one of these tests (verbal fluency) compared to control. Women from all trial groups exhibited a remarkable reduction in the Simple Response Time (alertness) test (P = 0.001). Thus, physical exercise performed close to AT is more effective to improve cognitive processing of older women even if conducted acutely, and using a customized exercise prescription based on the anaerobic threshold should optimize the beneficial effects.

Respostas cardiovasculares durante a postura sentada da Reeducação Postural Global (RPG) / Cardiovascular responses in the seated posture of the Global Postural Reeducation (GPR) method

OBJETIVO: Avaliar as respostas da freqüência cardíaca (FC), pressão arterial sistólica (PAS), diastólica (PAD), média (PAM) e duplo produto (DPr), durante a postura sentada do método de Reeducação Postural Global (RPG). MATERIAIS E MÉTODOS: Nove voluntárias saudáveis (23±2,1 anos, 56,4±7,8kg, 1,61±0,05m, 21,6±2,4kg.m2-1), inexperientes na prática do método RPG, foram submetidas a uma sessão de RPG na postura sentada, realizada em três fases: repouso pré-postura, execução da postura e recuperação pós-postura. No repouso e na recuperação, as voluntárias permaneceram sentadas por 20 minutos, sendo PA e FC verificadas a cada cinco minutos. A fase de execução da postura foi realizada em três séries e mantida por três minutos cada, com intervalo de um minuto entre elas. A verificação da PA e da FC foi realizada a cada um minuto e 30 segundos de execução da postura. RESULTADOS: Os valores de PAS, PAD, PAM e DPr foram significativamente maiores (p<0,05) do terceiro ao nono minuto da execução da postura (154±14, 107±11, 122±9mmHg e 16.478±2.802mmHg.min-1) quando comparados aos valores de repouso pré-postura (109±10, 74±7, 85±8mmHg e 9.374±1.687mmHg.min-1) e aos valores de recuperação pós-postura. Porém, estes valores retornaram aos valores de repouso nos primeiros cinco minutos de recuperação pós-postura. Durante a execução da postura, a FC não foi estatisticamente diferente da FC de repouso pré-postura. CONCLUSÕES: Elevações significativas da PAS, PAD, PAM e DPr foram observadas durante a execução da postura sentada da RPG empregada nesse estudo, mas retornaram aos valores de repouso nos primeiros cinco minutos de recuperação pós-postura.

OBJECTIVE: To evaluate heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP) and double product (DP) responses in the seated posture of the Global Postural Reeducation (GPR) method. METHODS: Nine healthy female volunteers (23±2.1 years; 56.4±7.8kg; 1.61±0.05m, 21.6±2.4kg/m²), without experience of the GPR, method underwent a treatment session in the seated posture. It was a three-step experiment: pre-posture resting, posture maintenance and post-posture recovery. In both the resting and the recovery step, the volunteers remained seated for 20 minutes and arterial pressure and HR were measured every five minutes. The posture maintenance step lasted for three minutes and was implemented three times with one-minute intervals between implementations. Arterial pressure and HR were measured every 1.5 minutes, while the posture was being maintained. RESULTS: The SAP, DAP, MAP and DP values were significantly greater (p<0.05) from the third to the ninth minute of maintaining the posture (154±14, 107±11, 122±9mmHg and 16,478±2,802mmHg/min) in comparison with the pre-posture resting values (109±10, 74±7, 85±8mmHg and 9,374±1,687mmHg/min) and the post-posture recovery values. However, these values returned to the resting values within the first five minutes of post-posture recovery. The HR while maintaining the posture was not statistically different from the pre-posture resting HR. CONCLUSIONS: Significant increases in SAP, DAP, MAP and DP were observed while maintaining the seated posture of the GPR method that was used in this study, but these values returned to the resting values within the first five minutes of post-posture recovery.

Identificação do limiar anaeróbio em indivíduos com diabetes tipo-2 sedentários e fisicamente ativos / Identification of the anaerobic threshold in sedentary and physically active individuals with type 2 diabetes

OBJETIVO: Comparar intensidades de limiar anaeróbio (LA) obtidas a partir do lactato, ventilação e glicemia em diabéticos tipo-2 ativos (DA) e sedentários (DS) e não-diabéticos ativos (NDA), e correlacionar variáveis metabólicas, hemodinâmicas e de composição corporal com o LA. METODOLOGIA: Grupos de DS (n= 09, 56,7 ± 11,9 anos), DA (n= 09, 50,6 ± 12,7 anos) e NDA (n= 10, 48,1 ± 10,8 anos) foram submetidos a um teste em cicloergômetro com incrementos de 15W até a exaustão. Freqüência cardíaca, pressão arterial (PA), percepção de esforço, lactato, glicemia e variáveis ventilatórias foram mensuradas nos 20seg finais de cada estágio de 3min para determinação dos limiares de lactato, ventilatório e glicêmico. RESULTADOS: As intensidades associadas ao LA identificado pelos diferentes métodos não diferiram entre si (p> 0,05). As intensidades absolutas foram menores para o grupo DS em relação aos grupos ativos (p< 0,05), não sendo observadas diferenças entre os grupos para as intensidades relativas ao consumo máximo de oxigênio ( por centoVO2 pico) e potência máxima ( por centoPpico) de ocorrência do LA. Observou-se correlação significativa entre LA e o percentual de gordura (r= -0,52), com tendência à correlação entre o LA e a glicemia ambulatorial (r= -0,33). Variáveis hemodinâmicas e LA não demonstraram correlações. CONCLUSÃO: O LA foi identificado a partir das técnicas estudadas em diabéticos tipo-2 e não-diabéticos. Apesar das diferenças entre grupos para as intensidades absolutas (Watts), a patologia pareceu não influenciar as intensidades relativas em que o LA foi observado. O LA apresentou correlação com a composição corporal e tendência a se correlacionar com a glicemia ambulatorial, sugerindo-se, com isso, o LA como um parâmetro importante na avaliação clínica destes pacientes.

OBJECTIVE: To compare anaerobic threshold (AT) intensities determined from blood lactate, blood glucose and ventilatory responses among sedentary (SD) and physically active (AD) type-2 diabetics and active non-diabetics (AND), and to correlate metabolic, hemodynamic and body composition variables with the AT. METHOD: The SD (n= 9, 56.7 ± 11.9 years), AD (n= 9, 50.6 ± 12.7 years) and AND (n= 10, 48.1 ± 10.8 years) groups performed a cycle ergometer test with increases of 15 watts every three minutes until exhaustion. Heart rate, arterial pressure, perceived exertion, blood lactate, blood glucose and ventilatory variables were measured during the last 20 seconds of each incremental stage, to determine the lactate, ventilatory and glucose thresholds. RESULTS: The AT intensities identified by the different methods did not differ from each other (p> 0.05). However, the absolute intensities were lower for SD than for the active groups (p< 0.05). No differences in intensity were found between the groups in relation to maximum oxygen consumption ( percentVO2 peak) and maximum power ( percentPpeak) at which the AT was observed. There was a significant correlation between AT and percentage fat (r= -0.52), and there was a trend towards correlation between AT and ambulatory blood glucose (r= -0.33). The hemodynamic variables did not show any correlations with AT. CONCLUSION: The AT was identified by means of the techniques studied, among type 2 diabetics and non-diabetics. Despite the differences between the groups with regard to absolute intensities (watts), diabetes did not appear to influence the relative intensities at which the AT was observed. The AT presented a correlation with body composition and a trend towards correlation with ambulatory blood glucose, thus suggesting that the AT is an important parameter in clinical assessments for such patients.