1.3 to 5 days
2. Aerobic or anaerobic
3.30 to 60 min
Answer:
Some things to consider: safety, Money, and specific muscles you want to work.
Explanation:
Free weights cost less money. People have used free weights on a weight bench and have not used a spotter. The free weights have fallen on them and killed them. A universal machine is more expensive. You can not drop a universal machine on yourself. The machine's aslo require little to no maintenance. A machine will basically always hit certain muscles, not due to you but down to how the machine is made. However free weights allow you to hit a larger variety of muscles as it's not isolated.
Panic attacks and anxiety
You would feel muscle weakness and fatigue(tiredness, reduced power) . When muscle cells dont get enough oxygen rich blood to working muscles they get a burning soreness from the buildup of lactic acid produced by glycolosis