It is impossible to influence the length of life, because the laws according to which each person is assigned a particular body are beyond all control. You have assumed a certain body, and you must inhabit it for a certain period of time. The length of life is originally assigned to us by our karma, based on the consequences of our past actions. Since God is life, He alone gives it, specifies its duration, or prolongs it, no one else.
Karma and Reincarnation
Under the Influence of the Three Attributes of Material Nature, the incarnate soul, led astray by the false ego, believes it is the author of its actions, while they are actually performed by nature.
By indulging in their favorite passions and hobbies, surfers believe they are exercising their full freedom of action, and this, they believe, in one of the best ways possible. But what they do not know is that all living beings in this material world are subject to the strict laws of material nature (imposed by the three attributes and modes of influence of material nature: virtue, passion, and ignorance), and that by using their human form inappropriately (like a fish), they will be forced at the time of death, by order of this same nature and of the Master of nature, Krishna, to don the body of a fish.
The materialist remains convinced, under the influence of the false ego, that he is the cause of everything he accomplishes. Unaware that the body's mechanism is a product of material nature, acting under the direction of the Supreme Lord, he is also unaware that, ultimately, it is under the control of Krishna. To be convinced that he acts of his own accord and in complete independence is a sign of his ignorance. He does not know
that his gross (material) body as well as his subtle (ethereal) body were created by material nature, under the direction of the Supreme Lord, and that, for this reason, all physical and mental activity must be placed in His service, in Krishna consciousness. He forgets Krishna's other Name: Hrishikesa, the master of the senses.
For too long he has misused his senses in the constant pursuit of new pleasures, and now he is led astray by his false ego, forgetting, because of it, his eternal relationship with Krishna. What you loved to be during your life, surfing, eating, mating, you will become at the moment of your death, if you think about it. You will thus become a fish to surf them. Those who have killed animals will reincarnate as those animals in their next successive lives, and will in turn be killed in the same way. Your thoughts at the moment of your death determine what your next existence will be. Think of God at the moment of your death, and you will return to his eternal kingdom.