This is a great question and I am happy to see it being asked. Too many men and women at this age just give up. I am 41 currently and I am in excellent shape and health. I urge you to see my before and after photos here.
I’m not sure how overweight you are but this will apply to most people in your situation.
First and foremost, you will absolutely 100% need to change the food you are eating. This is assumed because you are already “reasonably” active and again, I don’t know how overweight you are.
So, this would consist of eating lean proteins such as:
- Lean beef or steak
- Chicken (lean, no skin)
- Lean Pork (not a huge fan myself)
- Good fish (tuna, snapper, grouper, mahi-mahi etc…)
Keep in mind, these are only a few sources. I will let you do the research to find what is best for you. You will also need to incorporate many vegetables into your diet for so many reasons, but spinach, broccoli, asparagus are a good start. I would like to point you to this post as well, as I feel you will benefit from it greatly. Finish this then come back and read this here.
Now that that is out of the way – you are already halfway there, if not more than halfway.
I can tell you that there are so many different approaches to this question, however, strength training will yield fast results. Lifting heavy weight burns fat fast. It is a tough start and may not be the right choice for you. It all depends on what you can physically do, but definitely check out Stronglifts 5×5 on the app and play store. It will guide you through this or at least you can look it over. It is free by the way.
Since you have the luxury of a gym, I would suggest starting with some machines on your first trip. Maybe do some bench, tricep pushdowns, lat pulldowns, air squats, pushups, dips. You could run on the treadmill for a few minutes (a few like 3 at a slow pace.)
The point is that you first need to familiarize yourself with the equipment available to you, while not hurting yourself too bad where you will give up. See how you feel the next day, which I would expect you will be quite sore and then skip a day and go back. Do the exercises that felt most comfortable with and you feel you can get results from.
You will naturally find a routine of your own in a short time and keep evolving as you continue going. You should do this 3 times a week.
If you happen to be a man that is very overweight or just overweight – I urge you to visit my link to see my before and after photos on my crazy amazing journey of weight loss transformation at 40+ years young.