Muscle Science Thunder Energy Pre-Workout delivers fast explosive training results for a more powerful body: including energy stamina. It contains proven muscle-building L/Citrulline malate; L/Arginine Alpha/ketoglutarate (AKG); Green Tea Extract and Coffee Bean Extract. maximum performance from both your body and brain. This will give an extreme pump and strong mental focus on exercise Take it 10 min before the exercise for a fantastic result.