The winner of the 98th Tour de France will be crowned on Sunday, when the 21-stage, 2,131-mile bicycle race concludes in Paris. But the event has been tainted by ongoing allegations of blood doping and the use of performance-enhancing drugs by cycling’s top performers, including last year’s winner, Alberto Contador, and seven-time Tour de France winner Lance Armstrong, who retired from the sport in February. We asked Dan Lebowitz, executive director of Sport in Society, a Northeastern University research center, to analyze the impact of such illegal practices in professional sports.

Performance-enhancing drugs (PEDs) have made professional athletes bigger, stronger and faster. But how have they changed the fan experience?

Perhaps the biggest change relative to fan experience with respect to PEDs is the new aura of suspicion around all excellent performance in sport. This taint is not specific to the Tour de France and speaks to the larger societal issue of whether the application of science has encroached upon certain social, human, and moral ethics, including those in sport. Much of athletic fandom is about the amazement relative to ability. The presence of PEDs in sport now creates the dynamic question of whether that ability is defined as natural ability or enhanced ability. Unfortunately, this provides an asterisk to all athletic feats.

Lance Armstrong’s athletic accomplishments have enabled him to make a widespread humanitarian contribution through his foundation. To what extent do Armstrong’s philanthropic contributions outweigh the allegations of blood doping leveled against him?

In many respects, this question is the same as the first, in that it puts an asterisk on all of his accomplishments. This is at once both a sad and unavoidable consequence of PEDs in sports. Undoubtedly, his phenomenal athletic performance gave him an international profile and platform that allowed him to do many great things in the areas of awareness, consciousness-raising and philanthropy relative to cancer. These contributions have been real, impactful and sustaining. The human condition is complex and — like all of us —Armstrong embodies a capacity for both greatness and for failings. His work and commitment in the area of cancer prevention is not minimized by his alleged use of PEDs. Still, in the court of public opinion and in the arena of role modeling, cheating by any means should not be condoned or celebrated.

Officials in a number of sports, from cycling to Major League Baseball, have been accused of turning a blind eye to the use of PEDs. How much blame do you place with officials for the problem of PEDs in athletics?

When instances of bad personal decision-making are under such an intense spotlight, it is often popular to avoid accountability and deflect blame. We live in a culture where we’ve come to expect superhuman performance in almost all aspects of life. However, there is a difference between pushing the envelope of human expectation and promoting a culture of cheating. In the end, all of us have a choice about which path we will choose — and personal accountability always seems like the best route. If Armstrong used PEDs, even if the culture around him led him to that choice, this entire asterisk era can be seen in a positive light in that it has created a new era of consciousness about the culture of sport.

Major League Baseball and the International Cycling Union have responded to the resultant scrutiny with a progressive mindset about how to move forward. The greatness of the human condition is that it allows us to learn from past mistakes.