Autotrophic organisms are capable of synthesizing their own food and nutrition by harnessing sunlight and water.
Along with the entire kingdom Plantae and the following organisms are autotrophs:
Algae
Cyanobacteria
Seaweed
Phytoplankton
Fungi are heterotrophs, particularly of saprophytic nature. This means that they release enzymes on organic matter. These enzymes digest the organic matter into nutrients that the fungus can then utilize.
The last suggestion is correct....when you have setes of rest in between workouts..you allow the lactic acid to seep into your muscles and ensure that the muscle protein is broken down properly.