Young football players aerobic performance in sub-maximum exercise with exhaustion at a altitude without acclimation: esperience in El Cóndor.

Abstract

Antecedents: With the same intensity of submaximum effort, the concentration of serum  (LS) or muscular lactate is higher in Hypoxia conditions, or exercise at an altitude without acclimatlon, in relation with normoxia or at sea level (MSL). The hlghest level of  lactate  after fatigue or in a test of strict anaerobic condition, would not be modified when altitude   changes without prevlous acclimation. Objective: To abtain local data about the magnitude   of the aífect In SL of a effective altitude at 1,700 meters without acclimation, as a  parameter of aerobic performance of young soccer players of our environment who uve and  train at sea level. Volunteers and Methods: Self-controlled experimental test with a number   of 10 volunteers (16 - 18 years-old), soccer players of lower leagues from an important  local sport club. Two tests in a cycle ergometer of a graded physical effort until fatigue, the  first one in the Center of High Performance at MSL (474 meters) and the second one in the  town El Condor (EC; 2.220 meters), province of Cordoba. Exercise Protoco1: warm-up 2',  30 Km/h with 50W; 3 consecutive steps of 3' + 50W each one; final phase 30 Km/h of  200W until fatigue and/or symptoms or maximum time of 15'. SL and HR measurement: basal; the last 30" of every step and tu fatigue. SL determination with Accusport®. Two- tailed paired test. Results: 1 volunteer dropped out befote completion in EC (n=9). Mean  basal SL 2.1 mmol/L at MSL and EC (p=0.897). Mean dlfference (MD) EC vs. MSL ±  Standard error of 0.5 ± 0.2 (p=0.033), 0.9 ± 0.3 (p=0.008) and0.6 ±  .31nmol/L(p=0.103)lnsteps 1, 2,3 respectively of sub-maximum effort. In fatigue (the   highest level), Mean SL and Confidence Interval (CI) 95% of 7.6 (6.5-8.8) and 9.5 (7.8- 11.2) mmol/L at MSL and EC respectively (p=0.030).Heart Rhythm (HR) without changes in EC in relation to MSL. 66% with a greater Borg scale and 33% of dizziness at EC. Conclusion: At an effective altitude at 1,700 meters without acclimation we can verify a  lower aeroblc performance with a subjective perception of a greater effort intensity, and  neurological symptoms of hypoxia can be objectlfied in onethirds of the cases.