As marathon pioneer Kathrine Switzer once said, 'If you are losing faith in human nature, go out and watch a marathon.' And year after year, millions of people all over the world do just that. Supporting runners on the sidelines of a marathon is undeniably inspiring. With creative signs, joyous cowbells and a front-row seat to world-class athleticism, there’s plenty of reasons for spectators to enjoy partaking in the race-day festivities and participating in cheer zones. But aside from cheer zones being fun for spectators, there is an undeniable impact they can have on runners as well. Sure, marathoners seeing their family and friends throughout the course can give them a great boost of energy, but what about cheer zones as a whole? Here are three reasons why we’re cheering for cheer zones. 1. Cheer Zones Can Increase 'Happy' Chemicals in the Brain Dr. Beth McQuiston, neurologist and medical director of Diagnostics at Abbott, explained that runners can experience increases in dopamine and serotonin ('feel-good' chemicals released in the brain that are known to promote feelings of motivation and confidence), as well as endorphins (another positive chemical signal associated with physical activity). But every brain is different. Some runners may be more anxious throughout the race and could benefit from social connections and the serotonin they typically provide. This means interacting with spectators along the course may provide a welcome boost of mental positivity. For others, especially those battling mental and physical fatigue, a spike in dopamine from the positive reinforcement spectators provide might be the key to crossing the finish line. In any event, the cheering, human connections and music cheer zones provide can be a lifeline for runners. 2. They Can Boost Motivation Olympic marathon runner Liz Yelling is no stranger to spectators. She's ran in front of millions around the world and can attest to the power of those cheering on the sidelines. 'When you have support on the course, it keeps you accountable for your performance,' Yelling said. 'It's very public, and I find that motivating. You don't want to let anyone down.' And as Yelling has participated in both high-profile marathons (like the World Marathon Majors) and more secluded events (like trail races), she’s felt a difference when cheer zones are absent. 'When you're running alone on a trail, it's a very lonely feeling,' she described. 'It becomes an inward battle, and you're battling the negative thoughts and isolation alone. Cheer zones help that.' Pam Nisevich Bede, a 26-time marathon runner, agreed. 'Even in the less crowded areas of major marathon races, like around the United Center in Chicago right around mile 15 or 16 of the race, it gets quiet,' Nisevich Bede said. 'It's hard without that encouragement. The spectators give you adrenaline.' If you want to make a marathon runner’s race a little easier, maybe head to the less-dense areas of the race to give them some much-needed support. 3. They Give Runners Something to Look Forward to Abbott runner Claudia Guzman knew that her first marathon would be difficult. Heading into her race in Chicago last fall, she kept one thing in mind. 'I knew that at these specific miles, I would have my family, friends and co-workers,' she said. 'That got me through.' A marathon can feel endless. While finding your rhythm in a race is often thought to induce a runner's high, it can also make the 26.2 miles feel monotonous. Interacting with spectators can help break up the long run and keep runners feeling energized. 'In the last few miles, I was more excited to get to the cheer zones than I was to get to the actual finish line,' Guzman said. 'I needed that connection and celebration, and it pushed me to the end.' She specifically remembered how even spectators she didn't know gave her a 'perfect boost.' “That’s part of the reason that I decided to tackle the Boston Marathon next,” she said. “I knew that the race was challenging, but I also knew that the incredible crowd helps you power through.” And that she did. With two major marathon races under her belt, she’s now looking forward to her next one. 'It's a day where everyone is so positive. It's amazing that some people go out to support runners they don't even know. It really shows you the best of humanity.' So yes, a cheer zone's atmosphere, camaraderie and upbeat music are fun for spectators and one of the highlights of marathon day. But knowing that these spaces can also have a positive impact on the runners' mindset and performance is something to really cheer about. This article was originally published April 7, 2023, and updated May 19, 2023.