Gist
Yes. Treadmill walking is useful for general fitness because it improves aerobic capacity and endurance in a controllable format, though strength training is still needed for a complete routine.
Yes. Treadmill walking can build aerobic and walking endurance because it lets you control pace and duration precisely and increase workload gradually.
Yes. Treadmill walking can improve cardiovascular fitness when the speed or incline raises your heart rate and breathing enough to create a repeatable aerobic training stimulus.
Yes. Treadmill walking can support fat loss by increasing energy expenditure, but reducing body fat requires a sustained calorie deficit rather than a special treadmill speed.
Yes. Treadmill walking can support weight loss by increasing daily energy expenditure in a controlled, convenient format. The result still depends on an overall calorie deficit.