Supervisors info:
Όνομα Επιβλέποντα Καθηγητή
Τουμπέκης Ανάργυρος
Επίκουρος Καθηγητής, ΣΕΦΑΑ, ΕΚΠΑ
Όνομα Μέλους
Μπογδάνης Γρηγόριος
Επίκουρος Καθηγητής, ΣΕΦΑΑ, ΕΚΠΑ
Όνομα Μέλους
Παραδείσης Γεώργιος
Αναπληρωτής Καθηγητής, ΣΕΦΑΑ, ΕΚΠΑ
Summary:
The purpose of the study was to characterize the exercise intensity relative to critical speed (CS) during continuous and intermittent swimming. Twenty male swimmers (children,11.5±0.4 years, n=10 and adolescents 15.8±0.7 years, n=10) participated in the study. CS was calculated from all-out 200 and 400-m efforts. Lactate threshold (LT) was calculated using an incremental step-test (7x200m). On separate days participants performed two to four constant-speed efforts with a maximum duration of 30 minutes at a speed corresponding to CS, 2% above or 2% below CS, for the determination of the speed at maximum lactate steady state (sMLSS). A 10x200-m intermittent swimming at CS (10x200) was also applied in a separate day. Lactate concentration ([La]), oxygen uptake (VO2) and heart rate (HR) were recorded in each test. In children, CS was similar to sMLSS (1.092±0.071 m·s-1 vs. 1.083±0.065 m·s-1; p>0.05) but higher than LT (1.027±0.090 m·s-1; p<0.05). In adolescents, CS, LT and sMLSS were no different (CS:1.315±0.068, LT:1.317±0.065, sMLSS:1.297±0.056 m·s-1; p>0.05). Children and adolescents failed to complete 30 minutes of continuous swimming at CS (21.18±12.06, 25.66±7.44 min respectively; p>0.05). [La] was higher at the end of continuous swimming at CS compared to sMLSS in both groups (children: CS:4.0±1.8, sMLSS:3.4±1.5 mmol·l-1, p<0.05; adolescents: CS:4.5±2.3, sMLSS:3.1±0.8 mmol·l-1; p<0.05). VO2 in continuous swimming at CS was no different compared to sMLSS (continuous, children:83.8±17.5, adolescents:81.3±15.0, p<0.05; intermittent 10x200, children:84.7±17.1, adolescents:73.1±9.8% of VO2peak, p<0.05). HR was higher in continuous swimming at CS compared to sMLSS in both groups. At intermittent swimming, swimmers presented steady physiological responses between 200-m repetitions. CS corresponds to “very heavy” exercise intensity and is not a tolerable intensity at continuous swimming. In intermittent swimming, swimmers maintain CS, with physiological responses similar to sMLSS.
Keywords:
Critical velocity, physiological responses, intermittent swimming, continuous swimming.
