DOES N-ACETYLCYSTEINE SUPPLEMENTATION DURING AN ALTITUDE TRAINING CAMP ENABLE TRAINING QUALITY AND SUCCESSFUL PERFORMANCE OUTCOMES? A COMPARATIVE CASE STUDY

Abstract

INTRODUCTION & AIMS Elite athletes regularly incorporate training at altitude into their programs to enhance performance. However, the additional stress of exposure to a hypoxic environment needs to be carefully managed by coaches and sport scientists. Supplementation with antioxidants, such as N-acetylcysteine (NAC) may support the athlete’s immune system to cope with this stress. Preliminary evidence also suggests NAC may further promote haematological adaptations to hypoxia. Combined, the potential health and adaptive benefits of NAC warrant further investigation. Conducting ecologically valid and scientifically robust research in an elite sporting setting can be challenging due to small sample sizes, an inability to experimentally manipulate training, and the inherent complexity of the training environment. To account for these challenges, a comparative case study approach was used. METHODS Thirteen swimmers completed a three-week ‘Live-High, Train-High’ camp in Flagstaff, USA (elevation 2,100m). Beginning four days prior to the camp commencing, swimmers where randomly assigned in matched groups to consume NAC (1,200mg per day; n = 6) or a placebo supplement (n = 7) for 14 days. With each athlete defined as a case, fuzzy-set qualitative comparative analysis was used to examine the configurational effects of attributes (i.e., antioxidant support, sufficient ferritin, maintained body mass) previously associated with successful altitude training camps on physiological and performance outcomes. RESULTS NAC was not a solely sufficient or necessary attribute for increased haemoglobin mass. Higher consistency in haemoglobin mass was observed with high training quality. NAC and high training quality contributed to performance improvements. CONCLUSION Swimmer responses were highly individual with successful physiological and performance outcomes achieved by some, irrespective of having attributes that can impair adaptation to altitude training. Subjective training quality provided important contextual information. Fuzzy-set qualitative comparative analysis is a novel approach in sports science to evaluate the interrelationship of attributes that can impact performance.