Inclusion Criteria:  both sexes, age between 25 and 60 yrs old valid 5th category driving license for large trucks and coaches minimum of 3 years of continuous and verifiable documented work experience as a professional driver in the past 5 years diagnosed with moderate daily sleepiness as this is documented by a value >9 in Epworth Sleepiness Scale (SSC)  Exclusion Criteria:  drivers with a driving license that expires within a year of the recruitment date, disabilities that prevent them from walking independently or exercising, verified mental illnesses, alcoholism or drug abuses, or conditions that could affect the outcome of the study