Revista Brasileira de Medicina do Esporte
On-line version ISSN 1806-9940
LIMA, Anna Myrna Jaguaribe de; SOARES, Cláudia Maria Vieira and SOUZA, Alexandre Oscar Soares de. Effect of the work shift reversal on the aerobic capacity and cardiovascular responses to maximal exercise. Rev Bras Med Esporte [online]. 2008, vol.14, n.3, pp. 201-204. ISSN 1806-9940. http://dx.doi.org/10.1590/S1517-86922008000300008.
Sleep disturbs and associated alterations reach great part of the population which works at night, affecting their quality of life. The aim of the present study was to compare the aerobic capacity and the cardiovascular responses to maximal exercise in subjects with physiological sleep/wake cycle and with work shift inversion. 18 male subjects, aged 23-35 years, were assigned to either a shift-workers (Experimental; n=9) or a control group (Control; n=9). All the subjects underwent a treadmill exercise test in order to obtain the BP, HR behavior in the recovery period. Exhaled air was collected every 10 minutes for VO2max. Shift-workers presented lower heart rate values at rest (79.8 ± 11.5 bpm vs. 70.3 ± 3.8 bpm), 5th (112.7 ± 15,1 bpm vs. 98,7 ± 6,3 bpm) and 7th min. (108.7 ± 16.6 bpm vs. 93.9 ± 6.8 bpm) at recovery. SBP showed significant increased values in control group just at rest (110.0 ± 11.2 mmHg vs. 104.0 ± 5.7 mmHg). The control group presented lower values of DBP at the 5th min. (67.0 ± 4.4 mmHg vs. 58.9 ± 6.0 mmHg) and higher values of VO2max. (58.9 ± 6.1 ml/kg/min vs. 53.7 ± 2.5 ml/kg/min). We concluded that the alterations in the working shifts affect the circadian rhythms and the cardiovascular variables at rest and recovery periods of the exercise stress testing and can compromise the functional capacity of the subjects.
Keywords : VO2max.; cardiovascular variables; air traffic controllers; maximal exercise.