Supervisors info:
Κλεισούρας Β., Καθηγητής, ΤΕΦΑΑ, ΕΚΠΑ
Γελαδάς Ν., Επίκουρος Καθηγητής, ΤΕΦΑΑ, ΕΚΠΑ
Μαριδάκη Μ., Λέκτορας, ΤΕΦΑΑ, ΕΚΠΑ
Summary:
This study focuses on the genetic origin observed in cardiorespiratory endurance using the twin model paying particular attention to the acceptability of the underlying assumptions. Twenty pairs of male twins (10 MZ and 10 DZ) ranging in age from 18 to 25 years (22,4 + 2,2) were used as subjects. Every twin ran in a treadmill (constant speed of 8 Km . h-1) with progressive rise in slope 1% every minute to exhaustion. An ergospiromet¬ric system was used to determine the maximal oxygen uptake (VO2max) and ventilatory threshold (VT, V-slope method). Moreover, the heart rate was monitored by a telemetric system. Five minute after exercise, blood sample were taken to measure lactate concentration by spectrophotometer.
Statistical analysis was based on the acceptability of the model assumptions (t’, F’ and F tests). The heritability (h2) was estimated only if these assumptions were satisfied. H2 is defined as the proportion of phenotypic variance attributable to observed individual differences in actualized genetic potential. The heritability coefficient was 85% for VO2max in ml. Kg-1 . min-1, 86% for peak heart rate, 78% for maximum pulmonary ventilation, 97% for peak lactate concentration and 63% for anaerobic ventilatory threshold. The intra-class coefficients ranged for the above-mentioned attributes from 0.40 to 0.98 for MZ and from –0.10 to 0.55 for DZ twins. The genetic variation was not significant for respiratory ratio (F=0.88, ns) and respiratory frequency (F=2.6, ns). In conclusion, data obtained supports the hypothesis that genetic fac¬tors explain the largest part of the inter-individual variation in cardiorespiratory endurance during maximal and submaximal exercise, as well as anaerobic power.
