The present invention relates to a method and an apparatus for increasing the fertilizing capacity of sperm cells,The method comprising irradiating said sperm cells with non-coherent red light, the irradiation with non-coherent red light being performed in a discontinuous manner according to a pattern including at least one sequence of two irradiation periods of specific durations which are separated by an intermediate period of darkness of a specific duration.The apparatus is configured for implementing the method.