Before addressing the issue of how to improve running resistance, let's be clear about what resistance is in runners. It is nothing more than the ability of a runner to make a long-term effort, in our case, the race. Regardless of speed, we all must and want to improve endurance, as it is one of the key aspects in improving a runner, whether amateur, occasional, or professional.
If you are not a regular runner and you do it sporadically, you have a lot of room for improvement, and with "little" you do, you will quickly notice an improvement in your resistance, and what before seemed like an impossible distance, after a few weeks it will be a very affordable distance.
One of the first basic premises is regularity. It is of little use to go for a run once a week if we intend to improve resistance. Carrying out a type of training on a regular basis will undoubtedly lead your muscles to adapt to the race, you will increase lung capacity, etc... All with the simple fact of maintaining regularity and consistency in your jogging. If you want to improve, increase the number of running sessions, progressively.
Another thing that you can do, and once you have managed to find the necessary time to be able to train more regularly, is to try to increase the volume of the sessions, that is, try to do more kilometers each day that you train.
Always with your head, in a very progressive way, it doesn't matter if you add one more kilometer every day you go running, it may seem little to you, but it is not, all these kilometers add up little by little, and those kilometers are the gateway so that after a few weeks it already allows you to add 2 kilometers without realizing it.
Try not to do the same route every day, at the same pace, and for the same time. You will get bored before you get the expected benefits and the worst thing is that you will not improve.
You can combine sessions so long that used to prepare for a half marathon and slow, with shorter and faster sessions, making small changes of pace during the session will also help you a lot, combining, for example, two minutes at a fast pace, and two minutes at a slow pace, these sessions, in addition to making you get out of the routine, they will help you improve a lot and quickly.
Ideally, it would be to try to combine the running exercise with a strength session, either in the gym with machines, or in a more homemade way and at home, there are many exercises that will strengthen your legs using only body weight.
If you intend to improve resistance, and therefore, the increase in training days, will inevitably lead you to have to increase your caloric intake, that does not mean that you can "eat everything" with the excuse that you do more sport. You can and should eat more, since you will spend more energy and calories, but more does not mean worse... do not use sports as an excuse to eat "badly".
Try to give your body the energy it needs through a good nutrition for athletes, everything adds up, everything will make you improve quickly, but you must give your body healthy foods.
Finally, we must take into account the recovery after the sessions to improve the resistance running. Once finished we can relax with our Sizen, apply our favorite program and let the magic of pressotherapy take place.
With 30 or 45 minutes, about 2 hours after training and our legs will be fresh and ready for the next round.