What do you do before beginning a workout? Do you jump into the hardcore stuff right away or do you do a gentle warm-up beforehand? Most fitness trainers will tell you to do the latter. No surprise here. It’s firmly ingrained in our heads that we should warm up 10 minutes or more before tackling a workout. However, there’s little evidence that warming up before a workout enhances performance. In fact, long warm-ups may be detrimental to exercise performance by causing muscle fatigue.
What’s the Purpose of Warming Up Anway?
Why warm up at all? The goal of warming is to increase your core body temperature and boost blood flow to the muscles you’re working. With increased blood flow comes a greater delivery of oxygen to your muscles. Also, muscles that haven’t moved in a while aren’t as flexible and when they’re cold and stiff, they don’t have good range-of-motion. By warming up, you increase the elasticity of the muscles. In addition, there’s the perception that warming up beforehand enhances performance.
Finally, there’s a psychological component to a warm-up. When you do a warm-up, you prepare yourself mentally for the exercise session to come. However, studies among cyclists show that TOO long of a warm-up may actually detract from exercise performance by causing excessive fatigue.
Do Long Warm-ups Reduce Performance?
The purpose of a warm-up is to get your body and mind prepared for the workout ahead, so it’s not something you should skip. However, a warm-up doesn’t have to be long and drawn out to be effective. A 5 to 7-minute warm-up is enough to get the blood flowing to the muscles and raise your core body temperature without causing fatigue before your workout even begins.
Cyclists, before a competition, often warm up before a race with 20 or more minutes of cycling and even include some high-intensity intervals before the big race. It’s not surprising that they fatigue their muscles before the competition even begins. When researchers stimulated the leg muscles of cyclists electrically after a warm-up like this, the muscles contracted with less force than they did before the warm-up. The pre-race warm-up reduced their ability to generate force by tiring the muscles out. However, when the cyclists warmed up for only 15 minutes at a lower intensity, their muscles contracted with greater force and their performance improved. So, warming up MAY improve performance if you keep it short and lower in intensity.
While you probably don’t warm up in the same way a competitive cyclist does, this study raises the question of how much of a warm-up is too much and whether a shorter warm-up might be better. Warming up too long or too intensely may fatigue your muscles and reduce performance. It goes without saying that you shouldn’t approach a warm-up the same way you approach a HIIT session. If you’re doing dynamic warm-up exercises, like butt kickers, high knees, or jumping jacks, keep the intensity light. Otherwise, you’ll accumulate fatigue earlier and won’t perform as well. This has less meaning when you’re not in a competitive situation but still it’s something to consider.
Does Warming Up Prevent Injury?
What about injury risk? If cold, stiff muscles don’t move as well, it would seem that warming up lowers the risk of injury. However, the evidence here isn’t strong either. Human studies showing that warming up reduces injury are lacking. However, in animal studies, a warm muscle is harder to injure than a cold one. You have to apply more force and lengthen it more to damage it. In humans, if you look at the number of injuries as a whole, injuries appear to be more common in muscles that aren’t warmed up beforehand.
Another reason to warm-up is to give your cardiovascular system a chance to adapt to the stress of working out, especially if you’re doing high-intensity training. In one study, researchers asked 44 healthy men to run at a fast pace on a treadmill for 15 seconds. The guys took their short run without warming up beforehand. Afterward, 7 out of 10 of the men had abnormal activity on an ECG tracing. An ECG measures electrical activity in the heart. In a second experiment, 22 men jogged in place for 2 minutes at a moderate intensity before hitting the treadmill for a short, intense run. This time, only 2 of the men had ECG activity that was abnormal. Blood flow to your heart can’t always increase quickly enough to meet the demand for intense exercise when you first start. That’s why warming up is important for your cardiovascular system.
What’s the Best Way to Warm-Up?
A dynamic warm-up is best. Keep the old-school, static stretches for the cool-down when your muscles are warm and elastic. Holding stretches when your muscles are cold can reduce strength and power output, depending on how long you hold the stretch.
Begin by gradually getting your heart rate up with exercises like jogging in place, butt kickers, jumping jacks, etc. With these exercises, you’re moving multiple muscles and joints at once. Start out slow and gradually increase the intensity but don’t take it to the level that you’re huffing and puffing. You’re just trying to get your whole body warm.
You can also warm up by doing lower intensity versions of exercises you ’ll be doing during your workout. For example, if you’ll be doing squats, do squats without weights at a faster pace to raise your heart rate and get blood pumping to your muscles. Dynamic stretching is okay, as long as you’re not holding the position. For example, arm swings and kicks are dynamic movements suitable for a warm-up.
If you have muscles that are frequently tight, try foam rolling during your warm-up to loosen your muscles and boost blood flow. If you’re doing high-intensity interval training, include side-to-side movements as well, such as “skaters,” keeping the intensity low. Remember, the goal is to warm your muscles, increase blood flow without tiring your muscles.
The Bottom Line
Warming up not only warms up your muscles but it also activates your nervous system and gets it ready to work. Don’t skip the warm-up but keep it modest in length and the intensity light.
References:
New York Times Well. “When Warming Up for Exercise, Less May Be More”
J Strength Cond Res. 2010 Jan;24(1):140-8. doi: 10.1519/JSC.0b013e3181c643a0.
Active. “The Real Reason You Should Warm Up”
Related Articles By Cathe:
5 Reasons Why It’s Important to Warm Up Before Exercise
Two Types of Warm-ups and Why You Need Both Before Strength Training
