One of the benefits is the ability to maintain or increase muscle mass. That is a very important especially for older people.Weighlifting, in general, has many benefits if used in a correct way. Since i began teaing on a regular basis i have noticed many health benefits but mainly the feeling of being more robust.
I am doing this type of training for around 15 years. I tried many other training programs but HIT is the best. You need a very short time to complete the training. In a half an hour you can warm up, do the training and cool down. So you will have about 15-20 minutes active training. If performed until muscle failure, it is more than enough. Now , I am 45 and I do it about 3-4 time per week. In my 30-thies I was doing more frequently. One muscle group per day. For example:One main aspect i have noticed that for me contributes heavily is the abdominal bracing during lifting. The deep abdominal breathing combined with muscular exertion does give me an increased feeling of awakeness, which i personally attribute to increasing oxygen uptake. But that is just my experience. I do not recommend this to everyone.
For more info on H.I.T look up any of mike mentzers videos on youtube.
Monday - Back
Tuesday-Chest
Wednesday - Rest day or sometimes Arms.
Thursday - Shoulders.
Friday - Legs.
Saturday and Sunday, - Rest.
This works perfectly for me. I do 3 to 4 exercises in one session.
The trick is to warm up well, and do each set until muscle failure in a positive movement, and later when more experienced also in negative movements. Sometimes it needs one set, sometimes 2 or 3 sets. It depends on the day.
You can adjust exercises that suit you and that you can perform without any pain. For example, I can't do a flat bench press because I always hurt my shoulder with that exercise, while it is much better if I do a decline bench press. It is less stressful to the shoulder joint and puts much more pressure on the pectoral muscles. That works for me.Personally, I like weight lifting better too. Because of injuries, I'm not able to do really active stuff, but I can sit in a seat or lay on a bench and lift weights with my arms and legs in all kinds of ways. And yeah, the abdominal bracing and the resulting strengthening of the core is a big plus.
I think that Dorian Yates, an ex-Mr. Olimpia has some good videos on YT.
Just ignore the part about chemistry that he talks about and diet.
The tips about proper HIT training with weights are actually very good.