P.121Development of a rowing ergometer protocol to test whole body VO2peak in McArdle disease

Abstract

To design a rowing exercise protocol to assess whole body VO2peak in McArdle disease. In moderate to well-conditioned patients good muscle conditioning is most common in the legs but poor in the upper body. A means to both test, and condition, upper and lower body would be useful for high-functioning individuals. Three patients were recruited to develop a rowing protocol as proof-of-concept that a safe protocol to maximal intensity effort can be achieved and successfully produce values for VO2peak. Several grips on the ergometer handle were experimented with and differing power outputs used to find a common test protocol that all three participants could sustain to achieve maximal VO2 criteria of a plateau in oxygen consumption and a heart rate which is within 5-10bpm of age-predicted max. A two-stage protocol was derived; stage 1, participant begins at a selected very low wattage. Every minute the rower increases power output by 10W and rate of perceived pain and heart rate is recorded and power output adjusted to ensure second wind is achieved followed by 5 minutes at a power output that can be sustained without symptoms. There is then a five minute rest during which equipment is set-up to record VO2peak including fitting of a facemask to the rower. Stage 2 starts at 20W lower than the pace sustained during the 5 minutes at the end of stage 1. This is maintained for 3min and is then increased by 10W every 3 min until the rower can no longer sustain the power output for 30s.Throughout the handgrip can be changed from overgrasp to undergrasp and back to limit risks of isometric induced contracture. All three participants achieved a VO2peak between 20-30 ml/kg/min and there were no adverse events. This preliminary data suggests it is possible to safely use rowing ergometry to obtain objective, whole body conditioning data, via use of expired gas, during an incremental rowing protocol to max in those with McArdle disease.