People have been training their dogs to do tricks for centuries. In current times, dogs can earn AKC titles for performing tricks. There are four levels: Novice, Intermediate, Advanced, and Performer. The handler chooses ten tricks from lists that get more difficult at each level.
Here's a link to the AKC Tricks information.
Challenges for the Dog
Most tricks have low physical exertion. Handler (and dog) chooses what tricks to do from a list for each level. Not all dogs are interested in doing all the tricks - some won't pick up items, etc.
Challenges for the Handler
Low physical exertion.
Individual tricks can be fairly quick to train, some are more difficult . Not all dogs will willingly do all types of tricks.