One suggestion I don’t see here is to make use of compound exercises. They target multiple muscle groups and are designed to be more functional. They make your workout go quickly and improve movement efficiency and balance. They exist in body weight and weighted versions.
Another suggestion I don’t see above is to break the weight workout into 10-15 minutes per day and pick only a few areas to target each day. In a 7-10 day period you can cover all muscle groups multiple times. There are some nice reference books with such workouts that you can find at the library designed for women, or you can try one for men.
I have major time constraints in my life at present, and make use of both of these strategies for my weight workouts. I work out at home. We invested in dumbbells, kettlebells and we have a weight bench purchased from a store that sells resale sports equipment. It was cheap and we use it regularly.
I admit to being a Pilates junkie, and have been doing Pilates 3-4 days per week for 15 years. I also have Pilates equipment at home including a reformer with a tower, and our basement has a room with floor mats which is perfect for yoga or mat workouts. I used to run marathons but stopped after fracturing my femur while training for the Boston Marathon. (I tripped over a pothole that was hidden by the snow.) Since then whenever I have tried to run, I end up injured in some way….as I have been since April when I somehow tweaked both my Achilles and peroneal tendons. Maybe this time I have learned the lesson, no more running. I swam, taught swimming and was a lifeguard for many years. I no longer swim in pools because I became sensitive to the chemicals, and most pools in my community are too warm for laps. Rowing machines, walking and the Pilates reformer jump board are current form of aerobics.
I do not worry about protein. I generally eat a WFPB diet and have never counted how many grams of protein I eat. My goal with weights has been to build and maintain muscle mass, balance, and preserve joint, muscle and organ function as I age and I believe I am successful so far with greens, grains, beans, nuts and seeds. I do not use protein powder or bars.
Finally, I feel fortunate that my father (87) set an example of daily exercise. I did the Royal Canadian Air Force Exercise plan for physical fitness with him starting at age 7 and continued all through High School, plus he gave me a love for riding my bicycle, hiking, swimming, boating and all water sports. He encouraged my participation on sports teams in school. He continues to work out every day even if it’s only for a short interval. On days when I am tired or less motivated, I think of my dad and how he has been dedicated to daily exercise. I believe it has prolonged his life since he does not eat a healthy diet. I always feel better after I exercise.
One more tip which was mentioned above…while heavy weights are recommended, they are not absolutely necessary. In my experience, consistency is more important than how hard you work out. If you feel miserable after a workout, I would dial it back and do less. Doing something is always better than nothing. In Pilates we do only 5-8 reps of light weights for each exercise but focus on perfect form. I know from experience that this builds muscle. It may not be as fast, but it works.