Barfield, J.P., Malone, L.A., Collins, J.M., & Ruble, S.B. (2005). Disability type influences heart rate response during power wheelchair sport. Medicine and Science in Sports and Exercise, 37(5): 718-23.
Purpose:
An existing literature base and previous pilot study document that elevated work output is associated with involuntary movement. This suggests that individuals with cerebral palsy (CP) may demonstrate a greater heart rate (HR) response during competition than athletes with alternative disabilities due to mechanisms that are disability-specific. This study was designed with the primary purpose of examining the influence of disability type on HR response during competitive power soccer competition. The secondary purpose was to compare HR response during competition to cardio-respiratory fitness training for the general population.
Participants:
Power soccer players ages 8 to 55 years from the 2003 national power soccer tournament were recruited in this non-randomized trial with pre-test/post-test design. The sample of volunteers included 31 individuals with CP, 10 with spinal cord injury (SCI), and 7 with muscular dystrophy (MD).
Methods:
Individuals wore the Polar S610 HR monitor to record HR every 5 seconds through pregame and game conditions (games were approximately 50 minutes) as well as peak HR (highest HR during game), range (difference between pregame and peak HR), and HR response (difference between game (avg) and pregame). Game HR was used to estimate MET values, averaged for comparison to general population. Because subjects ranged in age from 8 to 55 years, regression for children was developed on subjects in the age range of 7 to 17 years and adult equations developed on subjects 18 years and older.
Results:
Data analysis found that athletes with SCI and CP were significantly older than athletes with MD in the sample. HR was found to have increased from pregame across all groups. The authors found a significant difference in HR response between the groups. The median HR response for subjects with CP was 12 beats per minute (bpm) higher (29 bpm) than subjects with SCI (17 bpm), which was a significant difference. Based on game HR, subjects with CP averaged an exercise intensity of 4.2 METs during competition. Twenty two subjects with CP (71%) exceeded the fitness training threshold for at least 30 minutes and 19 of these 22 exceeded the fitness threshold for the entire 50-minute game. Five subjects with MD (71%) and one subject with cervical SCI (10%) exceeded the fitness threshold of 55% estimated HRmax for 30 minutes.
Conclusion:
The authors found that disability type influences the HR of athletes during power soccer competition and revealed that athletes with CP recorded higher HR responses than athletes with SCI. This may suggest that there are increased activity demands for athletes with CP compared to those with SCI. The current findings also support the use of ACSM intensity guidelines for individuals with CP and MD. Although all participants were unable to sustain the training intensity, it is notable that the ability of power wheelchair athletes to reach training thresholds is associated with important health benefits.