During Ramadan, adult Muslims fast from dawn to sunset, abstaining from food and liquids. The fasting duration varies based on location and time of year. Ramadan fasting differs from other regimens as it is total (i.e., no food or fluids) and time-restricted, aligning with the circadian rhythm. This type of fasting can cause hypohydration, disrupted sleep patterns, mood swings, and increased fatigue. Muslim athletes who continue to train and compete during Ramadan face significant challenges. Research shows that the impact of fasting during Ramadan on physical performance varies depending on the intensity of the effort, ranging from no effect to substantial effects. This chapter aims to focus on the possible contributing factors (e.g., circadian rhythm, sleep, nutrition, hydration, and mood states) during the observance of Ramadan fasting that contribute to the decline of athletic performance and provide useful recommendations for athletes, as well as for coaches, healthcare practitioners, sports scientists, and those in sports management roles. The objective is to offer guidance on the implementation of effective behavioral modifications, social support systems, and psychological strategies to overcome these challenges.