Diet and exercise.
Diet: lay off the fat, sugar, grease, i.e. donuts, burritos, fast food, desserts...
Exercise: try the stationary bike one hour a day or at least three times per week.
The bike is less strenuous, easier on the knees and one only has to get one's arse into the gym. The bikes with the seat back are probably better for those with back concerns. Sweating all that water, one hour per session, chops calories and pounds.
There is nothing creative nor novel here just tried and true persistance.
Personal trainers can be accessed at much less $ but I suppose if one has the jing, pay more, if one thinks it will ensure desired results.
Some would rather MM stay rotund.