Is the Hayflick limit an absolute limit for the human lifespan or is it just the average limit of the human lifespan just like there are average heights and weights? Based on the maximum number of times the cells divide which is 50 according to Hayflick's experiments, how can the maximum theoretical lifespan of humans be calculated? A possible way to estimate lifespan as quoted from Wikipedia: "It has also been observed that the VO2max value (a measure of the volume of oxygen flow to the cardiac muscle) decreases as a function of age. Therefore, the maximum lifespan of an individual can be determined by calculating when his or her VO2max value drops below the basal metabolic rate necessary to sustain life ---approximately 3 ml per kg per minute. Noakes (p. 84) notes that, on the basis of this hypothesis, athletes with a VO2max value between 50 and 60 at age 20 can be expected "to live for 100 to 125 years, provided they maintained their physical activity so that their rate of decline in VO2max remained constant. A theoretical study suggested the maximum human lifespan to be around 126 years using a modified stretched exponential function for human survival curves." The scientific paper that the Wikipedia entry came from: http://link.springer.com/article/10.1007/s10522-008-9156-4 Does the value of 126 years estimated by this scientific paper match the maximum theoretical lifespan that can be calculated using the Hayflick limit?