In the past six months I have been asked more than once what the best exercise is.  The short answer is, of course, that there isn’t one.  The long answer is that the best exercise for you is dependent on your own phase of training and development at that given time. 

But let me attempt to actually answer that question. 

What we are looking for here is an exercise that benefits for strength, for endurance, for heart health, something that works the whole body, or pretty close to it, and something that can be done repeatedly. 

To me there are only two potential candidates; swimming and squatting.  Here is an overview of how each of these benefits according to our list:

There are few other things that could come close the challenging these two.  Deadlifts would offer pretty much the same as squats, and are more of a whole body exercise, but at best you could only deadlift two to three times a week.  It is possible to squat every day.  Cycling ticks a lot of boxes, but is far too leg dominant to provide balance to the body.  So what we are left with is two fantastic exercises.

Let’s consider each of these in a bit more detail in order to determine a winner.  Swimming works most of the muscles of the body by creating resistance from the water.  A long swim will build endurance, whilst a short swim would build muscular strength through speed.  Heart health is benefitted by the cardiovascular aspect of the exercise, and swimming could be done every day. 

Squats can also be worked for either strength or endurance, work the whole body because of the challenge heavier squats have on the body, and could be done frequently, as long as the load level is altered throughout the week.  Because of the challenging nature of the exercise there is a heart health aspect to it as well.

However, squats take a long time to master.  Learning the technique of the exercise can take a significant amount of time, and building the load up to the point where it genuinely challenges you can take longer.  Swimming can also take quite some time to master, however once you have the technique down it is a case of building fitness in the water.  Swimming technique can take longer to learn than squatting technique, especially if you are a novice to both, but improving your level can come far faster.  

In my opinion because of the constant challenge that resistance training brings it has far greater benefit in the long term than any other exercise.  I would urge you to include resistance training at the core of your workouts and programme in order to have a long term benefit towards any goal.  Therefore I believe that squats would be superior to swimming.