1. Anaerobic Power Output and Blood Lactate in Wheelchair Rugby Athletes Laurie A. Malone1, Ildiko Nyikos1, J. P. Barfield2 1Lakeshore Foundation, Birmingham, AL 2Tennessee Tech University, Cookeville, TN
Wheelchair rugby (WCR) is characterized by intermittent sprints interspersed with sub-maximal pushing and regular rest periods. Blood lactate is commonly used to monitor athlete performance and guide training, however little information has been reported regarding this aspect of training for WCR players with spinal cord injury (SCI). PURPOSE: To examine the relationship between anaerobic power output and blood lactate levels (BLa) among WCR athletes with tetraplegia SCI. METHODS: Fourteen male and one female WCR players striving for a spot on the National team [MAge = 29.5 ± 5.2 yrs; MWeight = ± kg; MHeight = ± cm; MVO2Peak = ± 5.95 (ml/kg/min); Player classification: 0.5 – 3.0; Yrs playing rugby = 7.53 ± 3.72; Yrs since injury = ± 7.15] completed a 30-s Wingate anaerobic test on an Angio arm ergometer (Lode B.V., Netherlands). The Wingate test resistance equated to 1-2% BM (Jacobs et al., 2004) based on player classification level (Classes 0.5, 1.0, 1.5 = 1% BM, Classes 2.0, 2.5, 3.0 = 2% BM). Mean and peak power (W/kg) were recorded, and BLa was measured (Lactate Plus, Nova Biomedical, USA) at rest and 3, 5, 9, and 30 min following completion of the test (passive recovery). IRB approval and participant consent were collected prior to testing. A repeated measures ANOVA (p < .05) was used to determine if a significant difference existed among BLa means across time points and Pearson correlations were run between mean and peak power at each BLa time point. RESULTS: Relative mean power output was 2.35 ± 0.82 W/kg and relative peak power output was 4.09 ± 1.54 W/kg. There was a significant change across mean BLa levels (F = 60.30, p =.000) across rest (1.88 ± 1.05 mmol/L) and recovery at 3 min (7.97 ± 2.20), 5 min (7.91 ± 2.85), 9 min (6.30 ± 2.56) and 30 min (3.20 ± 1.99). Post hoc comparisons revealed significant mean changes in BLa from rest to 3 min, 5 to 9 min, and 9 to 30 min (p < .05). Blood lactate was correlated with peak power at 3 min (r = .611, p < .05) and with mean power at all recovery time points (r = .839, .770, .710, .717, p < .01). CONCLUSION: Strong correlations were observed between mean anaerobic power output and BLa during recovery in WCR players. To better understand the physiological demands of WCR and to develop appropriate training workloads further assessments (field measurements, lab tests) are needed.
METHODS Participants Fourteen male and one female wheelchair rugby players striving for a spot on the National wheelchair rugby team were tested while attending a National team training camp. MAge = 29.5 ± 5.2 yrs MWeight = ± kg MHeight = ± cm MVO2Peak = ± 5.95 (ml/kg/min) Years playing rugby = 7.53 ± 3.72 Years since injury = ± 7.15 Player classification: 0.5 – 3.0 Test Protocol Each participant completed a 30-s Wingate anaerobic test on an Angio arm ergometer (Lode B.V., Netherlands). The Wingate test resistance equated to 1-2% BM (Jacobs et al., 2004) based on player classification level: Classes 0.5, 1.0, 1.5 = 1% of body mass Classes 2.0, 2.5, 3.0 = 2% of body mass Mean and peak anaerobic power (W/kg) were recorded, and blood lactate was measured (Lactate Plus, Nova Biomedical, USA) at rest and 3, 5, 9, and 30 minutes following completion of the test (passive recovery). IRB approval and participant consent were collected prior to testing. Statistical Analysis A repeated measures ANOVA (p < .05) was used to determine if a significant difference existed among blood lactate means across time points and Pearson correlations were run between mean and peak power at each blood lactate time point.
RESULTS Relative mean power output was 2.35 ± 0.82 W/kg and relative peak power output was 4.09 ± 1.54 W/kg. There was a significant change across mean blood lactate levels (F = 60.30, p =.000) across rest (1.88 ± 1.05 mmol/L) and recovery at 3 min (7.97 ± 2.20), 5 min (7.91 ± 2.85), 9 min (6.30 ± 2.56) and 30 min (3.20 ± 1.99). Post hoc comparisons revealed significant mean changes in blood lactate from rest to 3 min, 5 to 9 min, and 9 to 30 min (p < .05). Blood lactate was correlated with peak power at 3 min (r = .611, p < .05) and with mean power at all recovery time points (r = .839, .770, .710, .717, p < .01). CONCLUSION Strong correlations were observed between mean anaerobic power output and blood lactate during recovery in wheelchair rugby players. These correlations reveal that blood lactate assessment is appropriate for exercise prescription purposes specific to this population. Additionally, since mean anaerobic power output was strongly related to blood lactate at all recovery time points up to 30 minutes, this finding ensures coaches can monitor intensity at pre-determined breaks without interfering with intermittent training. Wheelchair rugby is growing rapidly in popularity and because aerobic exercise prescriptions may not be appropriate for the population it serves, appropriate training workloads need to be identified. This study documents the usefulness of blood lactate assessment as an appropriate guide for exercise prescription choices.
INTRODUCTION Wheelchair rugby (WCR) is characterized by intermittent sprints interspersed with sub-maximal pushing and regular rest periods. Blood lactate is commonly used to monitor athlete performance and guide training, however little information has been reported regarding this aspect of training for wheelchair rugby players with spinal cord injury. Atypical physiological responses to exercise make standard training recommendations potentially inappropriate for disability sport populations. Specifically, an atypical HR-VO2 relationship may exist for persons with tetraplegia spinal cord injury , establishing the need for valid anaerobic benchmarks for exercise prescription purposes. Unfortunately, the examination of blood lactate production in response to training has received less attention in this population. PURPOSE Therefore, the purpose of the study was to examine the relationship between anaerobic power output and blood lactate levels among wheelchair rugby athletes with tetraplegia spinal cord injury.
ACSM’10