subject: 7 Reasons Why You're Not Building Muscle [print this page] 7 Losing focus of your fitness goals7 Losing focus of your fitness goals. Finally if you're not gaining any muscle mass it may be due to lack of motivation. Can you honestly put 100% everytime you hit the gym? Ways you can help yourself stay motivated include keeping a training diary, taking before and after photos, getting a photo of a former hardgainer who's succeeded in gaining muscle, get involved with online fitness forums, watch training videos from former hardgainers and psyching yourself up before a training session with motivating music.