Add spaces: Goingforawalkonceadaycandowondersforyourwholeorganism.

Answer: Going for a walk once a day can do wonders for your whole organism.

Add spaces: Theicemancarriedafire-startingkitaswellasacontainerforcarryingembers.

Answer: The iceman carried a fire-starting kit as well as a container for carrying embers.

Add spaces: Workingcarefullywiththetechnique,hecontinuedtomaketestprintsuntilasatisfactoryresultwasachieved.

Answer:
Working carefully with the technique, he continued to make test prints until a satisfactory result was achieved.