Adaptation of the "Conconi test" to children and adolescents.

A field test for the determination of anaerobic threshold (AT) based on the relationship between work intensity and heart rate was previously developed in adult runners (4) and then applied in various sports activities (3, 5, 9). In the current study the same relationship between running speed (S) and heart rate (HR) was determined in 274 healthy children and adolescents (169 males and 105 females). All tests were performed either outdoors on a 400-m track (n = 159, 110 males and 49 females) or indoors in a gymnasium (n = 115, 59 males and 56 females). The subjects increased their work intensity progressively from low to submaximal speeds. HR was determined by a heart rate monitor (Sport Tester TM PE 3000, Polar Electro, Kempele, Finland). In every subject examined, the linearity of the S-HR relationship was lost at a speed, called deflection speed (Sd), above which the increase in S exceeded the increase in HR. HR at Sd was defined as HRd. The respective test-retest correlation coefficients for Sd, HRd, and slope of the linear part of the graph were 0.990, 0.824, and 0.953 when determined outdoors and 0.996, 0.840, and 0.932 when determined indoors. The outdoor-indoor correlation coefficients were 0.934, 0.855, and 0.282, respectively, for Sd, HRd, and slope. The results suggest that application of this test to children and adolescents in running may prove useful in cross-sectional and longitudinal studies of the development of aerobic power during growth.

Noninvasive determination of the anaerobic threshold in swimming.

The relationship between swimming velocity (V) and heart rate (HR) was determined in 60 swimmers. The athletes were asked to increase their work intensity progressively, from low to submaximal velocities; HRs were determined by a telemetric cardiofrequency meter. In all the athletes examined and for each style employed, the linearity of the V3-HR relationship was maintained up to a submaximal velocity (deflection velocity, Vd), beyond which the increase in work intensity exceeded the increase in HR. The test-retest correlation for Vd determined in nine pent-athletes was 0.99. Vd and anaerobic threshold (AT), determined through lactate measurements, were correlated in six swimmers (r = 0.84). Vd and average swimming velocities in a modern pentathlon swimming race (300 m free-style) were also correlated (n = 9, r = 0.91), thus suggesting that AT is critical in determining the speed in middle-distance swimming events.

Unmodified performance in runners following anabolic steroid administration.

The effect of a low-dose treatment (10 mg/day) of stanozolol on the anaerobic threshold (AT) and on maximal velocity (Vmax) was studied in ten well-trained runners in a 6-week trial experiment. The serum levels of testosterone (T), interstitial cell-stimulating hormone (ICSH), and of follicle-stimulating hormone (FSH) were determined before, during, and after the steroid administration. No improvements of AT and Vmax were found. No improvement of the competition running times was observed during the experimental period. The ICSH and FSH serum concentrations did not change significantly, while a marked decrease of the T serum concentration was observed. It is concluded that a low-dose treatment of stanozolol, sufficient to depress the testicular function, does not improve athletic performance.

Noninvasive determination of the anaerobic threshold in canoeing, cross-country skiing, cycling, roller, and ice-skating, rowing, and walking.

The relationship between velocity (V) and heart rate (HR) was determined in four canoeists, 42 cross-country skiers, 73 cyclists, nine ice-skaters, 10 roller-skaters, 32 rowers, and 20 walkers. The athletes were asked to increase their work intensity progressively, from low to submaximal velocities; HRs were determined by ECG in roller-, ice-skating, and walking, or read on a cardiofrequency meter in canoeing, cross-country skiing, cycling, and rowing. In all the athletes examined the linearity of the V-HR relationship was maintained up to a submaximal speed (deflection velocity, Vd), beyond which the increase in work intensity exceeded the increase in HR. Vd and anaerobic threshold (AT), determined through blood lactate measurements, were coincident in 19 athletes (6 cross-country skiers, 3 cyclists, 2 roller-skaters, 3 rowers, and 5 walkers). Vd was correlated with the average speeds maintained in walking (20 km, n = 13, r = 0.88), cross-country skiing (15 km, n = 20, r = 0.80; 30 km, n = 8, r = 0.82; 12 km, n = 7, r = 0.86; 11 km, n = 7, r = 0.86) and cycling (1,000 m flying-start, n = 68, r = 0.83), thus showing that AT is a limiting factor in these aerobic events.

[Blood testosterone levels before and after races of various duration]. / Livelli ematici del testosterone prima e dopo corse di diversa durata.

The blood testosterone levels have been measured in nine middle-distance runners seven walkers and in eighteen marathon runners before and after races of different duration. Most of the athletes (24 out of 34, 70,6% of the population) have shown an increase in testosterone levels soon after physical exercise. The values varied from an average of 5,83 to 7,72 ng/ml in middle distance runners, from 4,70 to 6,70 ng/ml in walkers, and from 5,00 to 6,82 ng/ml in marathon runners. The Authors hypothesize that prolonged physical activity in well-trained athletes may determine an augmented incretion of testosterone.

[Endurance of 6 marathon runners before and after a "dissociated diet"]. / Valutazione della resistenza di 6 maratoneti prima e dopo "dieta dissociata".

The effect of a carbohydrate loading diet on the endurance of six male marathon runners have been examined. Endurance improved in three runners, remained unchanged in two, and worsened in one. Due to the possibility of negative effects on the performance capability, a runner should experiment his personal reactions to the carbohydrate loading diet before using it regularly for long distance competitions.

Determination of the anaerobic threshold by a noninvasive field test in runners.

The relationship between running speed (RS) and heart rate (HR) was determined in 210 runners. On a 400-m track the athletes ran continuously from an initial velocity of 12-14 km/h to submaximal velocities varying according to the athlete's capability. The HRs were determined through ECG. In all athletes examined, a deflection from the expected linearity of the RS-HR relationship was observed at submaximal RS. The test-retest correlation for the velocities at which this deflection from linearity occurred (Vd) determined in 26 athletes was 0.99. The velocity at the anaerobic threshold (AT), established by means of blood lactate measurements, and Vd were coincident in 10 runners. The correlation between Vd and average running speed (mean RS) in competition was 0.93 in the 5,000 m (mean Vd = 19.13 +/- 1.08 km/h; mean RS = 20.25 +/- 1.15 km/h), 0.95 in the marathon (mean Vd = 18.85 +/- 1.15 km/h; mean RS = 17.40 +/- 1.14 km/h), and 0.99 in the 1-h race (mean Vd = 18.70 +/- 0.98 km/h; mean RS = 18.65 +/- 0.92 km/h), thus showing that AT is critical in determining the running pace in aerobic competitive events.

[Determination of the anaerobic threshold by a noninvasive field in man]. / Un test da campo per la determinazione della soglia anaerobica nell'uomo.

The relationship between running velocity and heart rate has been determined in 320 runners. A deflection from the expected linearity of this relationship has been observed at sub-maximal running speeds. Deflection velocity and anaerobic threshold (established through blood lactate determination) were coincident in 10 runners, thus showing that the increase in running speed exceeding the augmentation in heart frequency above Vd depends on anaerobic ATP production.