Surf,
Exercise is like trading. There is a simplicity to it that you will recognize in 5 years as you watch all those poor lost souls at you local gym contorting their arms in strange ways.
Inventory your physical issues as a 40-50 year old man I am guessing.
Arthritis, bad knees , hips, high blood pressure.....And do no harm, proceed slowwwww.
Your vascular system especially....the heart ....need to slowly adapt to stress if it has not been positively stressed in many years.
Stress test at your local hospital before starting to see if a sustained elevated heart rate is ok for you. This is absolutely necessary.
Now, simultaneously lose weight And put on some muscle.Maintenance for each additional pound( 10-15) goal over years allows 30-50 calories/day additional to your diet.
Almost all the work and discipline is done in the kitchen not the gym or exercise room.
How....specifically....To do this. 2 multi joint compound moves/lifts in the horizontal plane and two in the vertical plane. That's it. No pufffy...puffy arm movements.
1) push-ups
2) standing rows.
3) and 4) Olympic clean and jerk.... Watc.h a YouTube video. You can do with light dumbbells
Doing #2 correct is practice. On your heels...don't bend knees forward to far beyond your toes, pressure on your hamstrings and ass, moderate arch back, elbow resting on knee
And row a dumbbell one handed. All the work is done with the posterior chain . Think don't use the quads and knees like A Sumo wrestler or NFL lineman.
3 and 4 integrate a squat and dead lift. The push/pull in the vertical plane into one complex move.. First think pull to clean the weight and end in a full squat position. Then stand for
Completion of the squat phase, then smoothly press(the jerk part) over your head.
Work light and fast. Find YOUR groove that is safe and stress free on your body.
Again, do no harm.Your vascular system.... ( re: blood pressure)will be positively stressed like running(cardio cannot do). Circuit training like this can be a PART of cardio but you still shoul do a bike or such.... 30 minutes 3 x a week.
All this can be done with a set of modern adjustable dumbbells in your home babysitting your new baby.
No one will call you a fat ass again and you will live ten years longer and feel great. I am sure of this.