Staying awake and alert during long poker sessions is crucial for performance. Firstly, prioritize sleep before games to ensure a fresh start. Consuming caffeine responsibly can help; coffee or energy drinks can boost alertness. Opt for light, nutritious meals and snacks like fruits, nuts, and yogurt to maintain energy levels without feeling sluggish. Hydration is key—dehydration can cause fatigue, so keep water nearby. Take short, regular breaks to stretch and keep blood flowing. Lastly, engage in light exercise during breaks to invigorate the body and mind, maintaining sharpness for strategic decision-making in poker.