Testosterone is the most important male hormone. Lack of testosterone can lead man to a hormonal imbalance, mood changes and impotence. It affects your training and your muscle gains. To boost it up you will have to do a few things. Make sure to go early to bed, improve your sleep quality, lose weight and exercise on a regular basis. Testosterone booster supplements can help to improve your sleep, these are minerals zinc, magnesium, and herbs like Tribulus Terrestris or DAA ( DI aspartic Acids).