"Biorhythms" and men's track and field world records

The claims that athletic performance, like all human behavior, are governed by three invariant "biorhythms" were tested for all men's metric world records in track and field from 1913-1977 (N = 700). Outstanding performances are said to occur during positive cycle phases; and poor performances, errors of judgment, and accidents, during the negative phases and particularly at crossover points (critical days). "Biorhythm" amplitudes were calculated, and a chi-square (X2) analysis was used to compare the frequencies of records occurring in the positive, negative, and critical phases of each cycle with a random model. The phase-distribution of records within each individual cycle fit the random model (X2 less than or equal to 2.22, P greater than 0.30). The combined effects of the three cycles, determined from the mean "biorhythm" amplitude (X2 = 1.30, P greater than 0.20) and the number of cycles in each phase (X2 = 3.50, P greater than 0.30), also showed no significant departure from the expected frequencies. The number of records broken on single or multiple critical days was as expected from the number of critical days in ech cycle (X2 = 3.37, P greater than 0.15). These data reinforce our previous study on Australian records and the preponderance of acceptable published research into sports, accidents, and medical data in that they provide no evidence of the existence or effects of "biorhythms."