A great way to build endurance is to run, cycle or swim
If your goal is to do these activities more efficiently you should lift weights to improve your strength so that you can run up a hill and reach the top with something left in the tank. Compound moves that require more than one joint (squats, bench presses and deadlifts) will contribute tremendously to the endurance you need when you are running, cycling or swimming.
In the past it was commonly believed that lifting heavy weights in the gym would only hinder your progress and make you muscle-bound and slow.
However, today we know that more muscle is a good thing. The more muscle you have, the more calories your body will burn throughout the day and the more capable you will be of performing any activity that comes your way.
A well-balanced routine is one that aims to optimize training volume (sets x reps x weight lifted) over time. The biggest mistake we can make when we start a new routine is to jump straight into higher volume training without proper preparation.When we feel enthusiastic about our training it is often the hardest to control ourselves from doing too much too soon.
Total training volume over time will boost muscle and strength gains as opposed to lifting heavy without a plan and jeopardizing the overall volume you can perform in the long run.
Renowned strength coach Mark Rippetoe used to say: “Strength improvement for people who are not already strong is the rising tide that floats all the other ships in the physical performance harbor.”
Strength training will boost your strength which will have a carry over effect on the endurance activities you do outside the gym. It makes sense then to weave some strength days into your training because the more muscle you can get working the more it will challenge your heart and your cardiovascular system.
You will run further, cycle faster and swim better.