What do YOU do when you feel this empty?
Go for a nice, long run or some sort of exercise. Get your heart rate at least up to 75% of your maximum and sweat... a lot. I feel better every single time. Hope the below helps. It did for me.
Healthy Heart Zone (Warm up) — 50–60% of maximum heart rate: The easiest zone and probably the best zone for people just starting a fitness program. It can also be used as a warm up for more serious athletes. This zone has been shown to help decrease body fat, blood pressure and cholesterol. It also decreases the risk of degenerative diseases and has a low risk of injury. Fats are 85% of food energy burned in this zone.
Fitness Zone (Fat Burning) — 60–70% of maximum heart rate: This zone provides the same benefits as the healthy heart zone, but is more intense and burns more total food energy. The percent of food energy from fat is still 85%.
Aerobic Zone (Endurance Training) — 70–80% of maximum heart rate: The aerobic zone will improve your cardiovascular and respiratory system and increase the size and strength of your heart. This is the preferred zone if you are training for an endurance event. More food energy is burned with 50% from fat.
Anaerobic Zone (Performance Training) — 80–90% of maximum heart rate: Benefits of this zone include an improved maximum (the highest amount of oxygen one can consume during exercise) and thus an improved cardiorespiratory system, and a higher lactate tolerance ability which means your endurance will improve and you'll be able to fight fatigue better. This is a high intensity zone burning more food energy, 15% from fat.
Red Line (Maximum Effort) — 90–100% of maximum heart rate: Although this zone burns the highest amount of food energy, it is very intense. Most people can only stay in this zone for short periods. You should only train in this zone if you have a very high fitness level and have been cleared by a physician to do so.