Punching training, for Muay Thai, using bag

Training for Muay Thai needs strong abs. So, combine with punching with abs movements.
Some tips:

•  Remember to keep the feet pushed in, ensuring that it does not lift up.
• Keep the hips firm, so that you work your stomach.
• Focus on speed, simultaneously moving back and forward fast.
• Mainly focus on getting the guard in place.
• Do not think of abs: when speed develops and you get the right form for punching, abs became firm on its own.