Where dose human(physical) evolution end?
The way we understand evolution right now it won't "end", evolution makes us more fit to thrive in an environment, many times evolution downplays traits you'd consider more consummate if they are not useful.
For example a wild cat is much smaller and weaker than a lion, but in an european forest where most animals are small the smaller size and better agility are better suited for survival.
Could we do this by non mechanical means(robotic attachments, implants, etc)?
Don't see why not, there are loads of other animals besides us with better muscles we could copy for a start.
The efficiency of human muscle has been measured (in the context of rowing and cycling) at 18% to 26%. The efficiency is defined as the ratio of mechanical work output to the total metabolic cost, as can be calculated from oxygen consumption. This low efficiency is the result of about 40% efficiency of generating ATP from food energy, losses in converting energy from ATP into mechanical work inside the muscle, and mechanical losses inside the body. The latter two losses are dependent on the type of exercise and the type of muscle fibers being used (fast-twitch or slow-twitch). For an overal efficiency of 20 percent, one watt of mechanical power is equivalent to 4.3 kcal per hour. For example, a manufacturer of rowing equipment shows burned calories as four times the actual mechanical work, plus 300 kcal per hour,[16] which amounts to about 20 percent efficiency at 250 watts of mechanical output. The mechanical energy output of a cyclic contraction can depend upon many factors, including activation timing, muscle strain trajectory, and rates of force rise & decay. These can be synthesized experimentally using work loop analysis.
Felines for instance have about 20% more efficient muscles than us.
Edited by corb, 29 October 2011 - 02:21 PM.