Professional sports will disappear, if communism is real. Sport should be massive and USEFUL for health, this is communist. And professional sports, or as they say, sports of high achievements, is a highly specialized type of activity of a select few who have passed through a selection sieve. Therefore, it cannot be massive. How can it not benefit the human body, because it makes a person work for wear and tear, with prohibitive stress. Hence, the conclusion immediately suggests itself: professional sports can exist only in an exploitative society, where a person is viewed as a commodity. They make money on it, squeezing out all the vitality. By the age of 30, the pro becomes, in fact, an invalid, thrown out of life, no money is worth the lost health. Moreover, I note that professional sports have nothing to do with sports as a correct way of life, these are gladiatorial fights on survival for the amusement of the idle public. Professionals develop a corresponding ideology. It is no coincidence that the outstanding athletes of the USSR very easily went over to the side of the counter-revolution and began to cheat on the system that nurtured them and fanned them with glory. The Olympic reserve schools were a kind of forge of anti-Soviet personnel. I hope you understand that professional sports and communism are not compatible.
Will be what people decide. Most likely, it will remain limitedly exclusively as an entertainment industry along with, for example, feature films and circus, and not as a sport of the highest achievements. There will be professional teams and athletes for demonstration performances, for the fans' pleasure. There will also be mass sports, but for physical development without exaggeration of high achievement sports that undermine health.
Under communism, as Vitaly S. correctly wrote above, professional sports in the form in which it exists now will disappear. Now professional sports represent rather not the achievements of a person, but the achievements of the state's sports machine, which the person (athlete) represents. Hence, as it is rightly noted, the exploitation of an athlete, subjecting his body to extreme loads (often significantly shortening life and depriving him of health), I am not even talking about doping - all countries of the world use doping in one way or another (it's funny when WADA banned us " meldonium "(calcium mildronate) in other countries, no one banned similar drugs, that is, the same mildronate, but they called it differently, the formula was slightly changed and use it). Thus, even now in many sports there is a situation of almost universal "cheating" at competitions. Under these conditions, the very meaning of competition, which consists in - 1) checking and developing the capabilities of the human body, 2) the spirit of fair play and competitiveness in equal conditions - has lost its original meaning. Sport, on the one hand, is mired in a heap of additional rules (any team game), referees and referees subjectively and often on the basis of political or financial considerations decide the case in favor of a particular team, and on the other hand, they are mired in various scandals (doping and political).
Communism, at least at its first stage, will turn sport into an amateur activity again. The sport will not go anywhere, but it will no longer be "professional" in the sense that the entire career and reputation of an athlete will ultimately depend on business and the state. Athletes will be "sponsored" by the communes and will compete among themselves in an atmosphere of calm and peaceful struggle, the exploitation of athletes by dishonest coaches and the creation of "sports cars" with scandals and doping will be impossible. But athletes will have the opportunity to interact more closely with scientists and physicians, who will determine (in physical sports) the norms and rules of training. It will be impossible to break these rules, and there is no need, because people will not give "their whole life" to sports. But due to more harmonious development and greater success in medicine, amateur athletes will quickly overtake the professionals of the XX and XXI centuries. Moreover, new sports will arise, possibly associated with weightlessness or distorted gravity. And competitiveness not only will not disappear, but will cover all spheres of society (by the way, this will lead to the fact that soon the main conflict of the first phase of communism will be the conflict between society and the individual). Actually, sport is more likely to be a "business of the young", as the duration of human life increases to 200-250 years (which will lead to an extension of youth in a person), the age at which people will enter "mature life" will somewhat move away ... Life will be divided into five major spheres - childhood, adolescence, maturity, old age and deep old age. Childhood will pass quite quickly, it will be briefbelt stage. Already at the age of 15 (remember that the total age is 200 years), a person will officially pass to another age and, in general, finish training and education. Then the "choice of activity" will begin, which will last up to 40 years. During this period, a person will be able to either master several simple professions, or receive an even deeper special education and master more complex professions. And at this time (conditionally "youth") he will have time for sports and an athlete's "career" in addition to other professions as a hobby. Then comes the longest period in a person's life (from 40 to about 140 years), relatively speaking - "maturity". In this period, the acquisition of professions will end. and from about 50-60 years of age, playing sports even at an amateur level will already become meaningless (the reactions are not the same as those of young people). But there will remain an opportunity to switch to intellectual sports - and they will develop very strongly, including computer (virtual) strategic games, which will be essentially multi-level, much more difficult than chess and go, and to complete which you will need knowledge of logic, philosophy, ethics, mathematics, etc. ., however, board strategies and role-playing games will also be developed (dozens of popular options will most likely appear). Well, it is needless to say that old age (140-180 years) and deep old age (180-200 years) - this will essentially be the time when a person will not work to the full, but rather engage in the transfer of life experience (including sports).
That's how I see it. By the way, I refer you to the "Green Book" of M. Gaddafi. He said there that the future of mankind is not professional, but mass amateur sports, when everyone is able to become an athlete without great efforts only because he is harmoniously developed. If a social democrat with an Islamic specificity of Gaddafi understood this, then even more so he can understand the communist of the future. Relatively speaking, people of the future in some areas will be deprived of such a phenomenon as "idols", "leaders", tk. the mass level in different competitive events will be high and all the "top" participants in the competition (and this will be tens and hundreds of thousands of amateurs) will be approximately at the same level, slightly above the level of millions, but still. And this will cause inevitable attempts to "return the old days" (but I got carried away, this is not the place to tell how this will affect the conflict between the individual and society).