High Intensity Training Effects on Aerobic Capacity in Men Firefighters

Abstract

Studies suggest that High Intensity Training (HIT) significantly improves endurance, cardiovascular capacity and cardiac function in athletes and untrained individuals. However, determination of optimal duration of HIT is questionable. Furthermore, we couldn't find any published studies which suggest the benefits of HIT in occupational physiology groups including firefighters. PURPOSE: To find out if HIT of short duration may improve aerobic capacity (VO2max) in men firefighters. METHODS: Ten men firefighters (age 41 ± 6.5 yrs) performed a total of 18 treadmill sessions of HIT over a period of 6 weeks. Each session consisted of eight 60-second intervals running on a treadmill at 90-100% maximum heart rate (HRmax) as determined by a graded exercise test (GXT). Recovery period of 2 minutes between each interval was defined as the subject returning to 70% or below of heart rate reserve (HRR). Prior to and after this 6-week intervention a GXT was performed using the metabolic system and VO2max was examined. The test consisted of a walking warm-up at 3 mph for 3 minutes, followed by an increase in speed over the next 5 minutes until a speed was reached that the subject could maintain for the remainder of the test (approximately 60-70% HRR). After the subject reached steady state of 60-70% of HHR, the running speed remained the same, and the grade was increased by 2% every 2 minutes. The test was terminated when the subject was unable to continue and reached volitional fatigue or a respiratory exchange ratio (RER) of≥1.15. RESULTS: Prior intervention VO2max in absolute terms was 4.18 ± 0.82 L/min, after intervention 4.31 ± 0.79 L/min; and VO2max expressed in relative to body mass terms was respectively 40.91 ± 6.71 ml/kg/min, and 42.7 ± 6.7 ml/kg/min. VO2max after 6 weeks of HIT improved significantly in absolute and relative terms (p < 0.05). CONCLUSIONS: Anaerobic interventions such as HIT are proficient and time-efficient and can be used for optimization of aerobic conditioning in men firefighters. A 6-week HIT program of short duration sessions improves aerobic capacity in men firefighters. However, more studies on a larger scale should be done.