Physiological correlates of middle-distance running performance. A comparative study between men and women.

To compare the relative contributions of their functional capacities to performance in relation to sex, two groups of middle-distance runners (24 men and 14 women) were selected on the basis of performances over 1500-m and 3000-m running races. To be selected for the study, the average running velocity (v) in relation to performances had to be superior to a percentage (90% for men and 88% for women) of the best French v achieved during the season by an athlete of the same sex. Maximal O2 consumption (VO2max) and energy cost of running (CR) were measured in the 2 months preceding the track season. This allowed us to calculate the maximal v that could be sustained under aerobic conditions, va,max. A v:va,max ratio derived from 1500-m to 3000-m races was used to calculate the maximal duration of a competitive race for which v = va,max (tva,max). In both groups va,max was correlated to v. The relationships calculated for each distance were similar in both sexes. The CR [0.179 (SD 0.010) ml.kg-1 x m-1 in the women versus 0.177 (SD 0.010) in the men] and tva,max [7.0 (SD 2.0) min versus 8.4 (SD 2.1)] also showed no difference. The relationships between VO2max and body mass (mb) calculated in the men and the women were different. At the same mb the women had a 10% lower CR than the men; their lower mb thus resulted in an identical CR.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of aerobic and anaerobic capacity of athletes in treadmill running tests.

The criteria of max VO2 and max O2D which are traditionally used in studying aerobic and anaerobic work capacity, have the different dimensions. While max VO2 is an index of the power of aerobic energy output, max O2D assesses the capacity of anaerobic sources. For a comprehensive assessment of physical working capacity of athletes, both aerobic and anaerobic capabilities should be represented in three dimensions, i.e. in indexes of power, capacity and efficiency. Experimental procedures have been developed for assessing these three parameters in treadmill running tests. It is proposed to assess anaerobic power by measuring excess CO2, concurrently with determination of max VO2. Maximal aerobic capacity is established as the product of max VO2 by the time of max VO2 maintenance determined in a special test with running at critical speed. The erogmetric criteria derived on the basis of the tests proposed, may be used for systematization of various physical work loads.     

Blood lactate concentration following intermittent and continuous cycling tests of anaerobic capacity.

The purpose of this study was to compare the time and the magnitude of peak blood lactate concentration [La] following three 90-s cycle-ergometer tests. Intermittent all-out, continuous all-out, and continuous constant cycling tests were performed by 19 hockey players and 19 physical education students. Eight fingertip blood samples were drawn 1-11 min into recovery. [La] was similar between 3 min and 8 min of recovery for the three 90-s tests. [La] at the individual peak time was similar to that in samples taken at 1-4 min for the intermittent all-out test, 2-6 min for the continuous all-out test, and 2-4 min for the continuous constant cycling test. The intermittent and continuous all-out tests produced higher [La] at the individual peak time than did the continuous constant test. The intermittent all-out test produced an earlier peak [La] than the continuous tests. Both time and magnitude of peak [La] are dependent on the mode of testing.     

Skeletal muscle oxidative capacity in young and older women and men.

It has been suggested that a decline in skeletal muscle oxidative capacity is a general consequence of aging in humans. However, previous studies have not always controlled for the effects of varying levels of physical activity on muscle oxidative capacity. To test the hypothesis that, when matched for comparable habitual physical activity levels, there would be no age-related decline in the oxidative capacity of a locomotor muscle, the postexercise recovery time of phosphocreatine was compared in the tibialis anterior muscle of young [n = 19; 33.8 +/- 4.8 (SD) yr] and older [n = 18; 75.5 +/- 4.5 yr] healthy women and men of similar, relatively low, activity levels. The intramuscular metabolic measurements were accomplished by using phosphorus magnetic resonance spectroscopy. The results indicate that there was no age effect on the postexercise recovery time of phosphocreatine recovery, thus supporting the stated hypothesis. These data suggest that there is no requisite decline in skeletal muscle oxidative capacity with aging in humans, at least through the seventh decade.     

Effect of step aerobics training on anaerobic performance of men and women

The purpose of this study was to investigate the effects of 10 weeks of step aerobics training on anaerobic performance of men and women. College-age volunteers (64 women and 54 men) were divided into step aerobics (33 women, 27 men) and control (31 women, 27 men) groups. Before and after the 10-week period, the subjects' body composition, muscular strength, Wingate anaerobic performance, and vertical jump anaerobic performance were determined. The step aerobics group participated in step aerobics sessions of 50 minutes per day, 3 days per week for 10 weeks, at 60-80% of their heart rate reserve. Results of 2 x 2 analysis of covariance with repeated measures indicated significant sex differences in percentage body fat, lean body mass, muscular strength, and in all of the measured indices of the Wingate Anaerobic Test. The step aerobics group showed significant improvement only in mean power relative to body weight compared with the control group and women showed significant improvement only in anaerobic power of vertical jump when compared with men. It can be concluded that 10 weeks of step aerobics was not effective in improving all of the measured anaerobic indices in men and women.     

A comparative study of sibship tests of linkage and/or association.

Population-based tests of association have used data from either case-control studies or studies based on trios (affected child and parents). Case-control studies are more prone to false-positive results caused by inappropriate controls, which can occur if, for example, there is population admixture or stratification. An advantage of family-based tests is that cases and controls are well matched, but parental data may not always be available, especially for late-onset diseases. Three recent family-based tests of association and linkage utilize unaffected siblings as surrogates for untyped parents. In this paper, we propose an extension of one of these tests. We describe and compare the four tests in the context of a complex disease for both biallelic and multiallelic markers, as well as for sibships of different sizes. We also examine the consequences of having some parental data in the sample.     

Effect of creatine phosphate supplementation on anaerobic working capacity and body weight after two and six days of loading in men and women

The purpose of this study was to determine the effects of 2 and 6 days of creatine phosphate loading on anaerobic working capacity (AWC) and body weight (BW) in men and women. Sixty-one men (n = 31) and women (n = 30) randomly received 1 of 3 treatments (4 x 5 g.d(-1) x 6 days) using a double blind design: (a) 18 g dextrose as placebo (PL); (b) 5.0 g Cr + 20 g dextrose (Cr); or (c) 5.0 g Cr + 18 g dextrose + 4 g of sodium and potassium phosphates (CrP). AWC was determined at baseline and following 2 and 6 days of supplementation using the Critical Power Test. BW increased significantly over time, and the mean value for the men was significantly greater compared to that for women, but there were no interactions (p > 0.05). There were gender-specific responses for AWC expressed in both absolute values (kJ) and relative to BW (kJ. kg(-1)), with the women demonstrating no significant interactions. For the men, CrP loading significantly increased AWC following 2 days (23.8%) and 6 days (49.8%) of supplementation vs. PL (kJ and kJ.kg(-1)). Cr supplementation increased AWC 13-15% in both genders compared to PL (1.1%- 3.0% decline); although this result was not statistically significant, it may have some practical significance.     

Cardiovascular and norepinephrine responses of men and women to two cold pressor tests.

Two types of cold pressor tests were used to study gender differences in cardiovascular and plasma catecholamine responses. Ten male and ten female, young, healthy Caucasian subjects participated. The tests consisted of (1) 5 degrees C air blown at 3.5-4 m/s onto part of the face for 4 min and (2) the open right hand immersed to the wrist in water at 5 degrees C for 4 min. Heart rate, blood pressure (BP), and venous plasma norepinephrine were collected before, during, and 5 min after the 4 min of cold exposures. Test order was decided by a Latin square design, and the subjects rested in a quiet room for 30 min between the two tests. All parameters demonstrated significant (p less than 0.01) increases from rest during the cold tests. Gender differences were significant (p less than 0.01) in diastolic and systolic BP in each test with the males having a greater response, but gender differences were not found in heart rate or norepinephrine concentration. The study demonstrated that gender differences exist in the blood pressure responses to local cold, but that the mechanisms involved do not include a parallel difference in heart rate or venous plasma norepinephrine concentration.     

A comparative study of the fibronectin-binding capacity of staphylococci

The comparative study of the fibronectin-binding capacity of S. aureus and S. epidermidis of clinical etiology was carried out. Fibronectin binding was evaluated by original methods: the indirect hemagglutination test and the passive coagglutination test. In this study the occurrence of S. epidermidis isolates, as well as their level (evaluated by the titer) of fibronectin binding, was shown to be lower than those of S. aureus isolates. Fibronectin-binding representatives of S. epidermidis lost this capacity after storage in semiliquid agar at 4 degrees C for 2 months.     

Musculoskeletal capacity of middle-aged women and men in physical, mental and mixed occupations. A 3.5-year follow-up

The musculoskeletal capacity of 44 women and 39 men, mean age 55.0 +/- 3.4 years, was studied at the beginning and end of a 3.5 year period. The measurements included anthropometrics, maximal isometric trunk flexion and extension strength, maximal isometric hand grip strength and back mobility. According to a job analysis the subjects were divided into three dominating work groups: physical, mental and mixed groups. The results showed significant changes in anthropometrics, maximal isometric muscle strength and in mobility. The body weight and body mass index among women and the body mass index among men increased significantly during the period. The body height and sum of the skinfolds had on the other hand decreased significantly for both women and men. Women showed significant decreases of 9% and 10% (p less than 0.05 and p less than 0.01) in isometric trunk flexion and extension strength, and an increase of 9% in back mobility (p less than 0.05). In mental work, most of the significant changes occurred among women. Men had significant decreases in isometric trunk flexion and extension, 22% and 16% respectively (p less than 0.001) and an increase of 13% in back mobility (p less than 0.001). The men doing physical work had most of the significant changes in musculoskeletal capacity. The results revealed accelerated changes in musculoskeletal capacity in middle-aged employees.     

Ventilatory threshold and work efficiency during exercise on cycle and paddling ergometers in young female kayakists

The aim of this study was to assess the effects of increasing specific (paddling erogmeter) and non-specific (cycle ergometer) exercise on parameters relating to the ventilatory threshold (Th_vent) and work efficiency in 11 young female flat-water kayakists. When these trained subjects were tested using non-specific workloads, their oxygen uptake (VO₂) values at Th_vent, as a percentage ofVO_2max (%VO_2max), were close to those of untrained subjects [74.2 (5.6) %VO_2max, mean (SD)]. However, when we tested the same subjects using specific exercise, we recorded values typical of highly trained athletes [84.8 (4.7) %VO_2max). For the non-specific exercise on the cycle erogmeter, we recorded work efficiency values close to those of untrained subjects [22.3 (2.5) %]; however, for the specific exercise on the paddling ergometer, we recorded much lower values [13.4 (3.0) %] both at the level of Th_vent. The work efficiency at two warm-up submaximal exercise loads on the paddling ergometer was non-significantly lower than values at Th_vent [12.3 (2.8) % and 12.9 (2.9) % respectively]. Significant correlations were found between maximal-performanceVO₂ (ml · kg^–1 · min^–1) and performance at Th_vent during paddling and race performance (0.623, 0.630 and 0.648 respectively, allP<0.05). Because the results of both specific and non-specific submaximal exercise tests are different, we suggest caution in the interpretation of physiological variables that may be sensitive to training status. The evaluation of Th_vent and work efficiency as supplementary parameters during laboratory studies enables the determination of the effectiveness of the training process and the specific adaptation of the subjects.     

A comparative morphometric study of sensory capacity in geometrid moths

Diet breadth and the degree of capital breeding have been established as major determinants of species‐specific ecology of herbivorous insects. Both of these variables are related to resource foraging and therefore can be expected to have effects on sensory capacity. However, such effects have remained poorly studied, let alone in phylogenetically explicit multi‐species comparisons. We contribute to filling this gap in a study of 60 species of geometrid moths (Lepidoptera: Geometridae), using adult head measures (eye size, antennal length and shape, forehead width) as indices of sensory capacity. When controlled for body size, eyes of the more capital breeding species (i.e. those with low contribution of adult feeding to reproduction) were found to be smaller, and female antennae shorter, than in income breeders. Feathery (vs simple filiform) male antennae were more frequently present in the capital breeders and in larger species. Regarding diet breadth, generalist species were found to have relatively wider male foreheads than specialists. The results suggest that (a) breeding strategy rather than diet breadth predicts sensory capacity in geometrids, (b) capital breeding (vs income breeding) is related to low sensory capacity in females, and (c) in contrast, males of the capital breeding species have evolved towards elevated olfactory capacity.     

A definition and systems view of anaerobic capacity

The purpose of this paper is both to define terms used in exercise physiology, i.e. anaerobic capacity, anaerobic work capacity and anaerobic potential, and develop a systems perspective of anaerobic capacity. Philosophical argument is used to support the proposed definitions and systems view, which is an approach to assist in the universal acceptance of such terms amongst scientific investigators, coaches and athletes, and provide a focus on physiological mechanisms associated with anaerobic capacity which may be the subject of future investigation.     

Effect of two and five days of creatine loading on anaerobic working capacity in women

The purpose of this study was to determine the effects of 2 and 5 days of Cr loading on anaerobic working capacity (AWC) using the critical power (CP) test in women. Ten physically active women randomly received 2 treatments separated by a 5 week washout period: (A) 18 g dextrose as placebo (PL) or (B) 5.0 g Cr + 18 g dextrose taken 4 times per day for 5 days. Following a familiarization trial, each subject completed the CP test at baseline and following 2 and 5 days of supplementation. The PL resulted in no significant changes in AWC following supplementation; however, Cr increased AWC by 22.1% after 5 days of loading (p < 0.05). There was a significant main effect for body weight (BW), however, there was no significant increase in BW due to Cr supplementation. These results suggest that Cr supplementation is effective for increasing AWC in women following 5 days of loading without an associated increase in BW.     

Stretch-shortening cycle during plantar flexion in young and elderly women and men

The stretch-shortening cycle (SSC) is a combination of eccentric and concentric muscle actions. The purpose of the study was to compare the SSC of four different groups comprising a total of 29 women and 30 men, divided according to sex and age (i.e. 20–40 years and 70–85 years). A KIN-COM dynamometer was used for strength measurements of the plantar flexion of the right foot. An electromyogram (EMG) from the gastroenemius muscle was recorded simultaneously. Maximal voluntary concentric muscle actions at 120° · s^–1 and 240° · s^–1 with and without prior eccentric muscle actions were performed. Average torque values of the range of motion between 90° and 99° of the ankle joint were extracted. All four groups were significantly stronger at 120° · s^–1 than at 240° · s^–1 for pure concentric actions. The average torque values of the concentric phases in the SSC movement were significantly higher than the torque values for pure concentric actions in all four groups and at both velocities. The EMG was significantly lower or unchanged in the SSC movement compared to a pure concentric action in all groups. A larger percentage increase in torque with prior eccentric action was found in young women compared to young men at both velocities. Our results suggested that the enhanced performance was even more marked when a concentric action was preceded by an eccentric action in the young women than in the young men, probably due to better utilization of elastic forces, but we could not demonstrate any age-related differences in enhanced performance with SSC.