The Conconi test: methodology after 12 years of application.

The protocol for the determination of the speed/heart rate relationship during incremental exercise previously described (so-called Conconi test) has been refined and in part modified during 12 years of application. The new protocol calls for time-based increments in exercise intensity that are uniform up to submaximal speeds and progressively greater in the final phase. As in the original article (18), the speed/heart rate relationship is linear at low to moderate speed and curvilinear from submaximal to maximal speeds. A method is presented for the mathematical definition of this relationship, with the calculation of the straight-line equation of the linear phase and the identification of the point of transition from the linear to the curvilinear phase (deflection point or heart rate break-point). Analysis of 300 tests selected at random from those in our data base (more than 5,000 tests) has enabled us to show that the speed at which the deflection point occurs is significantly lower (p < 0.001) than that at which the acceleration of the final phase begins. This fact demonstrates that the break-point is not brought on by the final acceleration called for in the test protocol. Analysis of the speed/heart rate relationship allows for the determination of the following additional functional indices: 1) maximal heart rate (in 21 athletes the maximal heart rate attained in the test and that attained while racing were equal); 2) range of heart beats defining the linear part of the speed/heart rate relationship; 3) range of heart beats from the deflection point to maximal heart rate; and 4) maximal aerobic exercise intensity, obtained through extrapolation of the straight-line equation to maximal heart rate. Data are provided on the conditions of the test subject that modify his speed/heart rate relationship, such as incomplete recovery from previous efforts, inadequate warm-up, or inadequate test procedure with too rapid increments in exercise intensity. Finally, criteria for test acceptability are presented.

Hematological indices of erythropoietin administration in athletes.

Recombinant human erythropoietin (EPO), commercially available since 1988, is thought to be used by athletes in aerobic sports for the purpose of increasing oxygen transport and aerobic power. In an attempt to identify EPO administration, we have studied the peripheral blood of 20 subjects practising sports at an amateur level. Automated cytometry was performed on the blood samples before and during 45 days of EPO treatment. The same hematological indices were determined for a control population that consisted of 240 elite athletes from various sports. As expected following EPO treatment, RBC, [Hb] and Hct increased significantly (increments of 8%, 6.3% and 11%, respectively). A significant increase in reticulocyte count was also observed. In addition, automated erythrocyte analysis showed a significant increase in cells with a volume > 120 fl and hemoglobin content (HC) < 28 pg (hypochromic macrocytes, or MacroHypo): 0.06 +/- 0.09% before EPO, 0.48 +/- 0.63% after EPO. The EPO-treated subjects differed from the control population having higher values for Hct, mean corpuscular volume (MCV), Macro and MacroHypo. To investigate the possibility of using such variations in blood parameters to identify EPO treatment, individual values for Hct, MCV, Macro and MacroHypo for treated subjects and controls were plotted. Using the percentages of MacroHypo, a cut-off value surpassed in approximately 50% of the treated subjects and in none of the controls was established.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Reduction of Hb levels during the racing season in nonsideropenic professional cyclists.

Hematological variables of 40 professional cyclists, all receiving intravenous iron supplementation, were followed during a 15-month period. Mean values for red blood cells (RBC), hemoglobin (Hb), and hematocrit (Ht) were significantly lower during the racing season (RS) than during the nonracing periods (NRP) (RBC: RS = 4.53 +/- 0.34 millions/mm3, NRP = 5.09 +/- 0.36 millions/mm3; line 7 of abstract: Hb: RS = 14.2 +/- 0.9 g/dl, MRS = 15.2 +/- 0.9 g/dl; Ht: RS = 40.7 +/- 2.7% NRP = 44.4 +/- 2.9%; P less than 0.001 for all). However, mean values for ferritin and mean corpuscular hemoglobin (MCH) were significantly higher during the racing season (ferritin: RS = 422 +/- 398 ng/ml, NRP = 311 +/- 321 ng/ml, P less than 0.05; MCH: RS = 31.5 +/- 1.3 pg, NRP = 30.0 +/- 1.4 pg; P less than 0.001). These results suggest that the reductions in RBC, Hb, and Ht found in professional cyclists during the racing season are not the consequence of a diminution of iron stores but rather of reduced erythropoiesis and increased RBC destruction.

Reduction of erythrocyte magnesium concentration in heterozygote beta-thalassaemic subjects and in normal subjects submitted to physical stress.

Erythrocyte and serum magnesium (Mg) concentrations have been assayed in a group of sedentary heterozygote beta-thalassaemic subjects (beta-thal), in a group of non-thalassaemic well trained runners before and after a 25 km running race, and in a group of sedentary healthy controls. The mean erythrocyte Mg concentration (EMg) found in beta-thal (2.72 mEq/litre) and in runners, both before and after the race (2.58 mEq/litre before, 3.10 after), was significantly lower than the EMg values from the control group (3.69 mEq/litre). We propose various hypotheses to explain the reductions observed.