1. Stretching is not going to prevent you from getting injured.
Have you ever run with a dog or watched a horse race? If you have, you probably noticed something interesting—none of these animals stretch before or after they run. Stretching before a workout seems to be something that only humans do.
Whether stretching can prevent injuries depends on the type of activity you’re doing and the type of injury you’re trying to prevent.
If the activity includes explosive or bouncing movements, like those in volleyball, basketball, and plyometric exercises, research has shown that stretching can reduce injuries by increasing the compliance of your tendons and improving their ability to absorb energy.
However, for low-intensity activities that don’t include bouncing movements, like running, cycling, and swimming, research has shown that stretching doesn’t prevent injuries because you don’t need very compliant tendons for those activities.
In regard to the type of injury, stretching can prevent muscle injuries, such as sprains and strains, but not bone or joint injuries. Bone and joint injuries, which are common among runners, are caused by increasing the training load too much too quickly.
2. You need to run more than you are.
If you want to become a better runner, the first step is running more. The number of miles (or amount of time) you run each week, every week, is the most important part of your preparation to become a better runner. I can’t emphasize this enough.
Running more stimulates many physiological, biochemical, and molecular adaptations:
1) An increase in blood volume: A greater amount of blood circulating in your body means a greater number of red blood cells, which transport oxygen. Inside the red blood cells is a protein called hemoglobin, which carries oxygen to your working muscles. These changes to your blood improve your blood vessels’ ability to transport oxygen.
2) Better fuel storage: Running lots of miles stimulates the storage of more fuel (glycogen) in your muscles and increases your body’s use of fat so that your muscles spare your reserved glycogen.
3) More efficient transport of oxygen: When you run a lot, your body creates more capillaries surrounding your muscle fibers. More capillaries means more rapid diffusion of oxygen into your muscles.
4) Improved ability to produce energy: Through the complex activation of gene expression, running increases how many mitochondria you have in your muscles and the number of aerobic enzymes contained within them. That combination increases your muscles’ capacity to produce energy aerobically.
Running more also allows you to see and experience places and things you wouldn’t otherwise see and experience and gives you a chance to discover things about yourself, such as discipline, courage, and the ability to meet a challenge.
Always increase your running mileage systematically and with reason behind it, and be careful because you can easily get injured if you increase your weekly mileage too quickly.
3. Running injuries have little to do with the shoes on your feet.
Unless you’re wearing a shoe that is completely wrong for your foot type and running mechanics (e.g., you’re wearing a cushioning shoe when you should be wearing a stability shoe), your shoes are not causing you to get injured.
The main reason why injuries happen is because the physical stress from running is too much for your body to handle at that time. The human body is great at adapting to stress, but only when you apply that stress in small doses. When you apply the stress too quickly for your body to adapt, something breaks down. So don’t train stupidly and you won’t get injured.
4. Long races are best run at times of the month when estrogen is high.
Estrogen is a runner-friendly hormone. It influences many aspects of a runner’s performance, including a shift in metabolism toward a greater reliance of fat when running at a submaximal pace. Relying more on fat means your muscles’ limited store of high-octane fuel—carbohydrate—is conserved. When male rats are given estrogen, they rely more on fat when running on a rat treadmill and can run for longer periods of time (for obvious reasons, this research can’t be done on humans).
5. Your muscle fiber type will dictate which races you’ll be best at.
Humans have 3 major muscle fiber types, with gradations between them, the proportions of which are genetically determined. If you’ve got lots of slow-twitch aerobic muscle fibers, you’ll be good at long-distance races; if you’ve got lots of fast-twitch anaerobic muscle fibers, you’ll be good at sprints. If you’ve got a 50/50 mix or 60/40 mix of slow-twitch and fast-twitch, you’ll be good at middle-distance races, like the 800 meters and mile.
Since it’s impossible to know what your dominant fiber type is without getting a muscle biopsy, the only way you can gain some insight is by running many different races and doing many types of workouts over a number of years to see what you’re best at. But once you know, train according to your fiber type. If you’ve got 70% fast-twitch fibers and 30% slow-twitch fibers, you could get through a marathon if you really want to run it, but it’s going to be tough road to hoe. You always want to train to your strengths; you’ll be most successful when you do what you’re genetically predisposed for.
6. Your lung capacity has nothing to do with your ability to run.
At first glance, distance running seems to have everything to do with big, strong lungs. After all, it’s through our lungs that we get oxygen. If the size of our lungs mattered, you would expect the best distance runners to have large lungs that can hold a lot of oxygen. However, the best distance runners in the world are quite small people, with characteristically small lungs. Total lung capacity—the maximal amount of air the lungs can hold—is primarily influenced by body size, with bigger people having larger lung capacities. There is no relationship between lung capacity and how fast you run a 10K. I’ve measured this myself in the lab.
Studies clearly show that the lungs do not limit the ability to perform endurance exercise, especially in untrained people. That limitation rests on the shoulders of the cardiovascular and metabolic systems, with blood flow to and oxygen use by the muscles the major culprits.
If you’ve been told to take deeper breaths when you run to get in more oxygen, don’t listen. At sea-level, your blood is nearly 100% saturated with oxygen, even when running fast. Taking deeper breaths doesn’t get more oxygen from the lungs into the blood.
If you’re a fitness professional, don’t forget to register for the new Run-Fit SpecialistTM certification and get CECs from NASM: http://run-fit.com/runfitspecialist.
Jason,
I agree stretching doesn’t prevent injury. But are there other reasons to stretch? I always thought stretching keeps our range of motion from shrinking too much as we get older. I’m trying to avoid running with little baby steps like I see in a lot of the oldest runners.
Cynthia,
Yes, the main reason to stretch is to increase flexibility (range of motion). I didn’t speak about this in the blog post because I had to keep it short to address all of the other points. Stretching to increase flexibility is best done apart from the workout.
Jason