Is 50 lb. adjustable dumbbells enough weight for strength and fitness training ?

[lair8]

If you go for isolation excercises rather than compound exercises, probably yes.

[rabbit33]

To the specific point of weights, I prefer single-weight weights.

For example I have various exercises that I do with two different weights of dumbbells. Instead of something adjustable that I have to switch the weights back and forth, I have a pair of 12 lb ordinary cast iron DBs and a pair of 15 lb ordinary cast iron DBs. I just pick up one or the other depending on the next exercise. Similarly, I don't put plates on and off a long bar when I go from the lighter weight exercises to the heavier weight ones; I have two long bars a standard one for bench press and a curls bar.

Bars, dumbbells, all that stuff is so cheap that my time to swap back and forth is worth more than the cost of a few more pounds of cast iron.

[eddie gein]

Originally Posted by king john IV

1. "Can you walk briskly..." my retired doctor said if i could talk, i was not walking fast enough for cardio benefits

This is terrible advice in the era of inexpensive and convenient cardiac monitoring.

[YevTK]

At your age and with your back issues I would recommend you consider exercise bands with wall anchors instead of dumbbells. I used to lift weights but I find the bands put less stress on my joints.

When using bands with anchors, if you feel any muscle issues you can simply step forward to relieve the pressure. Bands also allow eccentric exercise which helps muscle growth.

Due to your back problems, I would also recommend you do belt squats vs regular squats to alleviate any load on your spine. You will need to get or build some sturdy platforms to stand on.