Well, both have their advantages and dis-advantages.
Disadvantages: You really need to think about the following…
- If the weather is not conducive to run outside, such as when it is raining heavily (and maybe it is a thunderstorm), is really cold or very hot, then, it would not make sense to try to run outside.
- Running outside could be dangerous due to presence of wild critters such as street dogs, snakes etc. Not all places have street dogs running around and snakes are not present in certain areas, but this could be a real/true problem depending on where you live. Hey, some places, you could run into maybe even bears, mountain lions…if you happen to reside/run in such a location that has bears/mountain lions.
- Running outside, especially, when all alone, in deserted areas and during “odd” hours (like very early mornings or late evenings) could result in you getting mugged/harassed by thugs. Everyone carries a Cell-Phone and some Cash (and maybe other valuables too), which could be the target of thugs.
- Women/Girls who run outside need to be extra careful to run as part of a group or if they are running alone, then, to keep to areas which are well lit and are not deserted. Women/Girls who run outside, all alone, can be targeted by thugs and could end up becoming rape victims.
- When running outside, not all places have an exclusive Running/Jogging Track. You need to be careful to not get into an accident. For example, when running along a busy roadside, it is best to run facing the traffic. This is so you can see oncoming traffic and avoid getting into an accident.
- You need to be well prepared with (might need to carry along with you) Hydration, Electrolytes and if necessary, Energy Bars and such (and maybe a bear spray and/or pepper spray to counter critters and thugs, to be used for your protection, in case you unfortunately run into any of them). This is especially, if you are running very Long Slow Distances outside.
- Some cities have significant pollution issues. Running outside can cause respiratory problems.
- If you have specific allergies (such as from pollen for example), then, depending on the season, running outside can cause respiratory and other allergies.
- It is lovely to run outside, to enjoy the outdoors and to breathe the fresh air (assuming it is not a highly polluted city).
- You can change your route often, so it does not get monotonous.
- You can also run as part of a group, where you can enjoy others’ company,
- Running as part of a group will also help you keep to your Running Schedule, consistently.
- Does not cost any money. Just put on your Running Shoes (you will need to invest in a good, reputed Running Shoe) and go outside and run.
Using the Treadmill:
- For all the dis-advantages of running outside as discussed above, the Treadmill offers very good solutions, as you use them indoors, either in your own home or at a gym facility somewhere.
- Treadmills also offer the advantage of being able to be programmed to cater to your Training, at various levels of difficulties. You can program the Treadmill for hills at varying degree of elevations and such. When Running Outside, this might not be always possible, as you might live in an area where hills are not present.
- The main disadvantage of the treadmill is that you are indoors always (when using the treadmill) and that could get monotonous.
- While in a gym facility that might have multiple treadmills which could be used at the same time, working out with a group is still possible, but, again, going to the same place all the time, can get monotonous.
- To use a Treadmill, either you will need to buy one for yourself, which means spending on it initially and then, of course to take care of the maintenance of the treadmill over time, which means spending even more money. On the other hand, if you are using a Treadmill at a Gym Facility, then, you will need to pay for the Gym Membership.
So, both have their own advantages and dis-advantages. You will have to understand what your specific situation demands, and go whichever way is the most advantageous for you.
You could also do a combination of both, in a manner that suites you best!!!
Either way, be sure to prepare a Proper Personalized Training Program (you can do this yourself, if you are Qualified/Experienced to do so yourself, or this can be prepared by a Reliable/Experienced Coach), that includes your Running (with proper Warm-Up, Cool-Down & Stretching), appropriate Nutrition as well as adequate Rest & Recovery, and then, stick to this Training Regimen. This will then surely lead to Positive Results, with a minimum/no Injuries.