Double Anaerobic Threshold in Athletes

Study Overview
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Brief Summary
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During an incremental cardiopulmonary exercise test (CPET) performed with a ramp protocol, it is very important to determine the anaerobic threshold, defined as the point at which the metabolism switches from being predominantly aerobic to also being anaerobic. The anaerobic threshold can be determined invasively, by identifying the increase in blood lactates with an arterial sampling, or, more commonly, non-invasively by three methods: the V-slope method, the ventilatory equivalents method and by using end-expiratory oxygen and carbon dioxide pressure (PETO2 and PETCO2 respectively). Normally, the anaerobic threshold is determined by the first method and the other two are used to confirm the value. The finding of different anaerobic threshold values using these three methods has been reported anecdotally in the past, while a prevalence of 11% in a healthy population has recently been described. Regular training, particularly that aimed at endurance sports, is able to shift the anaerobic threshold to higher exercise intensities. At present, the physiological reasons for the presence of a double threshold are unclear. The aim of the study is to identify the anaerobic threshold by means of the V-slope method and by means of the ventilatory equivalents method in athletes who have performed an incremental ramp CPET at the laboratories of the investigating centres, to assess in how many athletes a double threshold is present and to try to interpret the physiological/ pathophysiological significance of this finding. In this retrospective and prospective observational study, healthy male and female athletes who have had a cardiopulmonary test at our laboratories from 2007 to the present (retrospectively recruited) and prospectively recruited until the calculated sample size is reached will be enrolled.

Official Title
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Evaluation of the Presence of a Double Anaerobic Threshold in a Population of Athletes

Conditions
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Cardiopulmonary Exercise Test, Anaerobic Threshold, Athlete

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: no major present or past illnesses, no ongoing treatment At least 2 training sessions per week. Exclusion Criteria: Current illnesses and treatments for any physical condition that could potentially alter performance Subjects who have performed a submaximal test (RER < 1.05) CPET during which the AT determination is poorly assessable, i.e. due to changes in respiration. obese subjects (BMI >30)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Athletes groups | Identification of two groups of athletes (those with identified double anaerobic threshold and those without) | immediately after the incremental cardiopulmonary exercise test evaluation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Groups differences in age | Assess whether there are differences in age (years) between the two groups of subjects. | immediately after the incremental cardiopulmonary exercise test evaluation | 
| Groups differences in sport practised | Assess whether the two groups of subjects differ in term of the sport practised (information collected during patient interview) | immediately after the incremental cardiopulmonary exercise test evaluation | 
| Groups differences in exercise performance | Assess whether the two groups of subjects differ in term of exercise performance (peak power (Watts) reached during CPET) | immediately after the incremental cardiopulmonary exercise test evaluation | 
| Groups differences in VO2 | Assess whether there are differences in the oxygen intake VO2 (cardiopulmonary exercise test) between the two groups | immediately after the incremental cardiopulmonary exercise test evaluation | 
| Groups differences in VE/VCO2 slope | Assess whether there are differences in minute ventilation/carbon dioxide production relationship VE/VCO2 slope (cardiopulmonary exercise test) between the two groups | immediately after the incremental cardiopulmonary exercise test evaluation | 
| Groups differences in VE | Assess whether there are differences in minute ventilation VE (cardiopulmonary exercise test) between the two groups | immediately after the incremental cardiopulmonary exercise test evaluation | 
| Differences in VO2 at the two thresholds | Highlight the differences in oxygen intake VO2 (cardiopulmonary exercise test), in the subjects with double anaerobic threshold, at the two thresholds. | immediately after the incremental cardiopulmonary exercise test evaluation | 
| Differences in VE/VCO2 at the two thresholds | Highlight the differences in minute ventilation/carbon dioxide production relationship VE/VCO2 slope (cardiopulmonary exercise test), in the subjects with double anaerobic threshold, at the two thresholds. | immediately after the incremental cardiopulmonary exercise test evaluation | 
| Differences in VE at the two thresholds | Highlight the differences in minute ventilation VE (cardiopulmonary exercise test), in the subjects with double anaerobic threshold, at the two thresholds. | immediately after the incremental cardiopulmonary exercise test evaluation |