Can strength training improve endurance?

The answer is yes, but this conclusion has a very clear boundary of applicability, and there has never been any debate in the training circle about the suitability of the two. It does not mean that just two days of strength training will fully stack up the buffs for your endurance events.

In the running group I used to stay in, there was a buddy who was stuck at 140 for half a marathon for half a year. He used to be a pure aerobic person and couldn't hit 10 kilometers every day. But in the second half of the race, the pace dropped by 20 seconds. My heart and lungs were not yet strong. The lower limbs stopped first, and my legs were so weak that I couldn't even lift them. Later, I was advised to add 30 minutes of lower-limb strength training twice a week, which consisted of multiple sets of light-weight exercises such as bodyweight squats, clam poses, and calf raises. Two months later, I competed in the half-marathon, and my pace in the second half dropped by less than 5 seconds, directly reaching 134 PB. Before, I was afraid of training to strengthen my legs, but as a result, my leg circumference did not increase by half a millimeter, and my stride length became much more stable.

But not everyone agrees with this approach. Many veteran players who play ultra-long-distance endurance events feel that strength training is an "ineffective use of training time." I used to know an older brother who was doing 100-kilometer cross-country. I heard from a blogger that he practiced strength and endurance and added heavy squats and deadlifts twice a week. After practicing for a month to compete, his legs started to feel as heavy as lead after 30 kilometers. At this point in time, he was still in good condition. Later, I cut the weight of strength training to less than 40% of 1RM and replaced it with functional movements such as single-leg deadlifts and Bulgarian split squats that favor stability and force control, and then I slowly regained my strength.

In fact, it is easy to understand to put it bluntly. Many people think that poor endurance means poor cardiopulmonary function. In fact, 80% of endurance bottlenecks encountered by amateurs are caused by the inability of local muscles to bear the burden first - just like if you run 30 kilometers and have weak legs, play badminton all afternoon and can't swing the racket, or climb a rock wall and your forearms are so sore that you can't hold on. In most cases, it's not that you are out of breath, but that the muscles that contract repeatedly are exhausted first. The corresponding strength training is actually "upgrading the hardware" of your muscles. On the one hand, it improves the anti-fatigue threshold of the muscles themselves. On the other hand, it corrects your force generation mode and reduces the useless power consumption of those blind exertions. It is equivalent to replacing a new battery with a higher energy density for your mobile phone. With the same power consumption, the battery life will naturally be longer.

But the easiest pitfall here is to train strength blindly. If you train with heavy weights and low number of sets every day, you are training for absolute strength, and the muscle fibers will grow in the direction of fast-twitch muscles. This will increase the oxygen consumption of the muscles. Your legs will feel heavy even after running for two steps. It will not improve your endurance at all, and may even hinder your legs. To adapt to the strength training of endurance events, it is basically a type of low load, high reps, biased towards force control and core stability, which is completely different from the training logic of bodybuilding and powerlifting.

If you are new to endurance events, for example, you have just finished running 5 kilometers or playing ball for half an hour and are still exhausted, then just build up the basic aerobic volume first. It is not cost-effective to add strength training at this time.； If you have been stuck in a certain performance range for a long time, and every time you push the limit, your muscles are the first to fall off, then adding two weeks of targeted strength training will most likely give you an unexpected surprise.