The mind, in its cleverness, comes up with many different ways of
entertaining itself, including sports.   It is important to examine these
ways of entertainment with intelligence, as the mind can come up
with harmful things.
This article is about sports, so let's shine the light of intelligence
at sports.   If your intent is to evolve spiritually, to have a joyful, healthy,
harmonious life, it's important to stay away from sports that weaken
your body = that affect your nervous system in a negative way.
Some people might view the body as a bag of bones that is to be
used and then disposed; they might be aware to some degree that they
are not the body, that the body is only a tool.   Those people might hold
that view as a defense (or justification) for engaging in intense things,
such as sports, race car driving, other forms of entertainment.
While it is true technically, practically the reality is that it is through
the body that you can "make" or "break" your energy.   Using the body,
the tool, incongruently (disharmoniously) can and does lead to your
energy being fragmented and/or depleted and/or spinning out of control,
and can open you to affection by negative energies.   All that could
negatively affect your following incarnations, and your soul, as well.
While you are incarnated (living on Earth), the body is not separate from
you - it is an extension of your Being.

Below is a list of challenges (= disharmonious things) that some sports
create/face.   It is not a complete list, of course.   If your intention is to be
as healthy as possible, it's important to chose a sport that is as harmonious
with your body as possible.   If you're not sure (or even if you think you
are sure) which sports is good for you, it's very beneficial to visit
a Neuro-Emotional Technique (NET) practitioner to find out for certain.
In some cases a relatively small adjustment can change a sport from
disharmonious to harmonious.
When you want to engage in an exercise, in sports, the first important
thing is that your body is open to the exercising, to the physical exertion.
The best way to find out is by using NET, as mentioned above.
Also, over-exercising, pushing the body too much, is best to avoid.
Exercising early in the morning without having proper breakfast is
not beneficial to the body.   The period between the previous-day's
supper and the current day's breakfast is a fast, and exercising right after
a fast without supplying the body with energy and nutrients is not
helpful (breakfast = break fast).

In general, the body doesn't like jarring, impact force, and being out
of alignment (poor posture).   So sports that expose your body to those
kinds of physical stresses are not appreciated by your body.

Stretching
Though stretching is not a sport by itself, it's an integral part of basically
all sports.   Stretching should be gentle, going only as far as the body
feels comfortable with, without pushing it, without bouncing up and down
or in and out.   The kind of stretching that uses tools or another person
to force the body to stretch farther and farther should be avoided.
Going only as far as the body naturally and relaxedly goes is good enough.
Stretching to the point of pain is stupid and destructive to the body.

Running or Jogging
Running on paved surfaces is too hard on the body.   Running on natural,
softer ground can be OK.   Of course, having good running shoes that
properly support the foot and absorb some of the impact is beneficial.
The same goes for jogging, though it's possible to jog on paved surfaces
without jarring the body by using a shuffle step.

Soccer
Soccer can be a great and fun exercise, but heading of the ball is a big
no-no.   The brain and the spine are not designed for that.   It doesn't take
much impact to the head/neck to weaken the body.   The force that the
flying soccer ball exerts on the head is way too much.   Heading of the ball
is bad for adults, and especially for children.   No heading of the ball if you
want to live a healthy life.   No exceptions.

American Football and Rugby
These sports are way too violent for the body.   The protective equipment
used in American Football is not enough to protect the body sufficiently.
However, the flag football can be a great way to have fun.

Hockey
Slamming players against the boards and body-checking is too violent
for the body.

Boxing and other forms of contact fighting
Boxing and other contact sports that include kicking and punching
an opponent are idiot sports.   The protective gear doesn't do much
to lessen the impact on the brain, spine, and other organs.

Swimming, Diving, and other water sports
Swimming is one of the best exercises, but not in chlorinated water.
Skin is not just a plastic bag covering the body.   It's an organ that
breathes and absorbs what it comes into contact with to some degree.
Being submerged in chlorinated water is no fun for the body.
Chlorine is a toxin.   Also, the interaction of chlorine with natural organic
matter in water creates disinfection byproducts, that are more than
10 thousand times more toxic than chlorine.
However, swimming in natural, clean water can be lots of fun.
Diving can expose the body to too much impact.

Dancing
Dancing is one of the best exercises.   However, dancing in high heels is
definitely bad for the body.   High heels shift the skeletal alignment to
unnatural positions, and the high heels don't offer sufficient support for
the feet.

Ballet
This form of dancing is perhaps the highest form of physical art.
It's one of the best ways to exercise.
Dancing on the toes the way the female dancers do, is not good
for the body.

Tennis
An easy-going game of tennis can be a great way to exercise.
However, once the players start hitting the ball hard, it's not as good.
Tennis players can hit the ball as hard as if chopping wood with an axe.
With so much power, proper body alignment is crucial.   Unfortunately,
it's hard to maintain proper body alignment when playing high-power
tennis.   Try to chop wood with the same movements that tennis players
use and you'll see.   If you asked a martial arts instructor to show how
he hits a punching bag with a right hook (tennis forehand), you'd see quite
a different body-alignemnt from how tennis players hit the ball.

Golf
Golf courses are beautiful, but the beauty and near-perfection of the grass
is mainly thanks to chemicals.   These chemicals are toxic to the body,
and to the environment.

Trampoline
Trampoline can be a good exercise if the body is loose enough
to handle the jarring.   Too many people have a tight, compressed
spine and tight muscles. For them trampoline is a destructive
exercise.

Bicycling
The horn bike seat is not a good support for the body.   The body is not meant
to rest on the area between the legs.   Not only are there important body parts,
but also a major meridian (energy channel) goes through there.
It is not conducive to good health to sit on the horn bike seat.   Even the modern
ones with a hole in the middle, and even lots of padding, may not be good
enough, especially for longer rides.   The Spongy Wonder Bike Seat is a great
and safe alternative.
As well, it's beneficial to have the bike seat stem (especially) and the forks
equipped with suspension to soak up bumps and holes, to reduce spine-jarring.
The racing position used on road bikes squeezes the internal organs, which
is not the best.   Recumbent bikes have a big advantage in this respect.
The forward-leaning position of a conventional bicycle influences the rider
to lift his/her chin up to be able to see the road ahead.   This is especially
pronounced on bikes with drop handlebars.   Riding over a bump or
a pothole can produce a sharp kick in the butt that jars the body,
and that can induce a whiplash.   Whiplashes are not good for the spine
and the nervous system.
To minimize the chance of a whiplash, it is beneficial to tuck the chin in,
in a relaxed way, when a bump/pothole is coming, to help protect the spine.

Unicycling
Unicycling is best to avoid.   It exposes the body to too much jarring
and bouncing.

It is vital to be aware that proper body alignment (proper posture),
freeness from toxins, freeness from jarring/violent impacts, and going
only as far as the body naturally feels are crucial to true healing/maintaining
good health.
To know if your body can handle the exercise that you want to do,
you can visit an NET practitioner (the best way), or a chiropractor.
The page Good Health Trinity has more info on
achieving/maintaining true good health.