If you are just starting out as a new boxer, muay Thai fighter, jujitsu grapple, or any other contact sport I always suggest consistency over workout time. You can always put in 1,2 or even 3 hours of time into a workout but if you'll end up being burnt out and sore for the next two weeks and even go to the extent of quitting the sport then what's the point of even putting in that 1 to 3 hour workout into effect? I always tell people to just put 10 minutes into the workout and workout everyday. 10 minutes may not sound like it is enough but try punching a punching bag for 10 minutes or even doing push ups for 10 minutes straight, but do it consistently. When your body is used to doing 10 minute workouts for a whole month straight and if it feels too easy, then go challenge yourself to do 20 or even 30 minute workouts everyday but remember to keep it consistent and always stick to your routine!