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Phthalocyanines are a group of porphyrin synthetic molecules. These compounds show outstanding photodynamic properties. This is due to their high ability to photogenerate free radicals, such as 1O2 and O.−2. However, the presence of different metals in the central core of phthalocyanines are able to modulate these characteristics. This study demonstrated that the photochemical activity of Zn, Cu, Ni, Co, Fe and Mn unsubstituted phthalocyanines differs, depending on the size and electronic configuration of the central metal. In addition, phthalocyanines showed different levels of photodamage against plasmid pBR322. Outcoming computational calculations will aim to clarify the photodynamic mechanisms of phthalocyanines. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine physiological, perceptual, and affective responses during self-paced walking for three age groups. 66 adult women were assigned into three groups by age: 20-25 yr. (n = 22), 30-35 yr. (n = 22), and 40-45 yr. (n = 22). Each participant completed a maximal exercise test and a 20-min. bout of walking at a self-selected pace. The preferred walking speed was similar for all age groups, whereas physiological responses relative to maximal and ventilatory threshold values were greater in the 40-45 yr. group than the other two groups. Nevertheless, perceptual and affective responses were similar for all age groups. These findings suggest that physiological responses, but not perceptual and affective responses, of sedentary women are associated with age during walking at a self-selected pace. DOI 10.2466/06.10.13.PMS.111.6.963-978

The aim of this study was to investigate the influence of adiposity (%body fat) on physiological, perceptual, and affective responses during walking. 45 women were divided into low, medium, and high tertiles according to %body fat. Each participant completed a maximal exercise test and a 20-min. bout of walking at a self-selected pace. The preferred walking speed was similar among groups, whereas %V[O.sub.2] max was greater in the high tertile group compared with the other two groups. Nevertheless, perceptual and affective responses were similar between the groups. These findings suggest that physiological responses relative to maximal capacity, but not perceptual and affective responses, of sedentary women are influenced by adiposity during walking at a self-selected pace. However, when the physiological responses are relative to ventilatory threshold, there are no differences between individuals with different levels of adiposity.

In order to examine whether environmental settings influence psychological and physiological responses of women with obesity during self-paced walking, 38 women performed two exercise sessions (treadmill and outdoors) for 30 min, where oxygen uptake, heart rate, ratings of perceived exertion, affect, attentional focus, enjoyment, and future intentions to walk were analyzed. Physiological responses were similar during both sessions. However, during outdoor exercise, participants displayed higher externally focused attention, positive affect, and lower ratings of perceived exertion, followed by greater enjoyment and future intention to participate in outdoor walking. The more externally focused attention predicted greater future intentions to participate in walking. Therefore, women with obesity self-selected an appropriate exercise intensity to improve fitness and health in both environmental settings. Also, self-paced outdoor walking presented improved psychological responses. Health care professionals should consider promoting outdoor forms of exercise to maximize psychological benefits and promote long-term adherence to a physically active lifestyle. [ABSTRACT FROM AUTHOR]

The object of this investigation was to establish a group-normalized perceptual response, using the Borg 15-category rating of perceived exertion (RPE) scale, that is consistent with the Surgeon General's recommendations for physical activity intensity. This normalized response is defined as a range of RPEs corresponding to a target physiological outcome during exercise common to a specified group of individuals. 24 college-age students (12 men; 12 women) underwent a progressive exercise test administered on a semi-recumbent leg cycle machine to estimate V[O.sub.2] peak and 12 6-min. exercise trials on a combined arm and leg exercise machine. Three trials were conducted per day, and at least 24 hr. separated testing sessions. RPEs between 7 and 10 were consistently estimated during trials categorized as light to moderately intense (35 to 53% V[O.sub.2] peak). These exercise intensities resulted in an energy expenditure of between 5.38 (SD = 1.37) to 7.56 (SD=0.60) and 3.58 (SD=0.58) to 5.30 (SD=0.97) kcal * [min..sup.-1] for these men and women, respectively. RPEs corresponding to 7: extremely light to 10: very light or light are sufficient in healthy young college students to achieve the target activity with respect to exercise intensity. Therefore, this group-normalized perceptual response, i.e., RPE = 7 to 10, may be expressed as a prescriptive reference enabling college-age individuals to produce an exercise intensity designed to promote health and studied longitudinally to assess the effects long term.

This investigation examined the validity of the Borg 15-category Ratings of Perceived Exertion (RPE) scale during semirecumbent exercise in 32 [degrees] C water. 9 men undertook 12 8-min. trials at 3 power outputs and 4 pedal-crank rates. The power output was distributed between the arms (20%) and legs (80%). RPEs were measured for the arms, legs, chest, and over-all body. Correlation coefficients for RPE expressed as a function of power output and gross metabolic efficiency (M[E.sub.G]) ranged from .56 to .83 and .54 to .70, respectively, for each pedal-crank rate. Validity coefficients were greatest at those pedal-crank rates having the highest M[E.sub.G]. The Borg 15-category RPE scale is valid for use during semirecumbent exercise in water.

This investigation examined the effect of carbohydrate substrate availability on ratings of perceived exertion (RPE) during cycling at moderate intensity to exhaustion and the relation between submaximal endurance performance and RPE obtained following 2 hr. of cycling at moderate intensity. Seven male cyclists performed two exercise trials at power output corresponding to 70% of their peak oxygen uptake until exhaustion. Subjects ingested either a 6% glucose/sucrose solution at the rate of 0.6 g [multiplied by] [kg.sup.-1] (Body Weight) [multiplied by] [hr..sup.-1] or an equal volume of artificially flavored placebo every 20 min. throughout the exercise trials. RPE for the legs, chest, and over-all body, and oxygen consumption, expired ventilation, carbohydrate oxidation rate, and blood concentrations of glucose, glycerol, and lactate were measured every 20 min. throughout exercise and at exercise termination. Statistical analysis of these dependent variables indicates that (1) an exercise-induced decrease in blood-borne carbohydrate substrate intensifies leg and over-all perceptions of exertion during the later stages of prolonged cycling at 70% V[O.sub.2]peak. (2) Factors other than availability of blood-borne carbohydrate substrate may influence perceptual intensity at exhaustion. (3) Ratings of perceived exertion for the legs and over-all body obtained after 2 hr. of cycling at moderate intensity may be useful in predicting submaximal endurance performance.

Studies the acute effect of ingesting amino acids on basal growth hormone (GH) secretion in young men who weight trained. Discussion of GH secretion; Increase in GH concentrations at 30, 60 and 90 minutes during exercise; Elevation of GH during resting conditions 60 minutes after amino acid ingestion.

The purpose of this study was to investigate the impact of self-selected and imposed exercise intensity on cardiorespiratory fitness and body composition in 75 obese women. The subjects were divided into: G1 (self-selected intensity); G2 (intensity 10% above ventilatory threshold); and G3 (control group, no exercise). The exercise program consisted of 12 wks. The findings demonstrated a significant improvement in cardiorespiratory fitness (VO2 max and HRVT) in G1 (3.55 mL.kg-1.min-1) and in G2 (9.69 mL.kg-1.min-1). There were no significant changes in body composition. In conclusion, the 12-wk program of self-selected and imposed exercises resulted in an improvement in cardiorespiratory fitness with no significant changes in body composition. The self-selected intensity demonstrated to be an important strategy in order to promote engagement of obese subjects in an exercise program. [ABSTRACT FROM AUTHOR]