A high-sugar diet negatively impacts physical performance by causing energy crashes and decreased endurance. Consuming excess sugar leads to rapid spikes and falls in blood glucose levels, resulting in fatigue and reduced stamina. It can also impair cognitive function, affecting reaction times and overall performance. Moreover, a diet loaded with sugars can contribute to weight gain, increased body fat, and decreased muscle mass. Long-term, this dietary choice can lead to chronic health issues, affecting athletes' ability to train effectively and perform at their best.