{'fraction_non_alphanumeric': 0.043173862310385065, 'fraction_numerical': 0.03325554259043174, 'mean_word_length': 5.038732394366197, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Do we underestimate VO2max in cancer survivors? Findings from a supramaximal verification test.

Cancer survivors demonstrate a reduced maximal oxygen uptake (VO2max) which is clinically relevant in terms of overall survival. However, it remains uncertain whether they attain their true VO2max in a cardiopulmonary exercise test (CPET). In the present study, a supramaximal verification bout (Verif) was applied in cancer survivors to confirm attainment of VO2max. Seventy-five participants (61±12 years, n=43 females with breast cancer and n=32 males with prostate cancer, 6-52 weeks after primary therapy) performed a CPET on a cycle ergometer and a Verif at 110% peak power output. As verification criterion, VO2max in Verif should not exceed VO2max in CPET by >3%. On average, VO2max was significantly lower in Verif compared to CPET (1.60±0.38 l/min vs. 1.65±0.36 l/min, p=.023). On the individual level, n=51 (68%) satisfied the verification criterion, whereas n=24 (32%) demonstrated a higher VO2max in Verif. N=69 (92%) fulfilled ≥ 2 secondary criteria for maximal exhaustion in the CPET. While VO2max was not underestimated in the CPET on average, still one third of cancer survivors did not attain their true VO2max. Verif appears feasible and beneficial to confirm true VO2max in this population. Furthermore, it might be more reliable than secondary criteria for maximal exhaustion. Novelty bullets: • In about one third of cancer survivors, VO2max is underestimated by a CPET. • This underestimation of VO2max is not necessarily indicated by secondary criteria for maximal exhaustion. • A supramaximal verification bout appears feasible and helpful for the determination of VO2max in cancer survivors.