Most of us have learned that we need some time to “warm up the engine” before starting into harder efforts. And anyone who has watched a time trial stage of any major cycling race has seen the pros ticking away on a trainer before they start. So what exactly is going on here?
It turns out there are quite a few factors involved here.
- Blood flow. At rest, your body isn’t sending much blood to your legs. Instead, a large amount of it is going to your digestive system, especially if you have recently eaten or had a drink. When riding, your legs need more blood since they are using more oxygen. Your body will constrict the blood vessels in your digestive system and dilate the blood vessels in your working muscles. This change takes time, and you can only ride at 100% aerobic capacity after this shift has occurred. It’s also why you don’t want to have a massive meal right before a hard effort.
In addition to greater oxygen delivery, your working muscles’ increased circulation increases your body’s rate to clear metabolic byproducts.
- Psychology. Being mentally prepared for the race or workout ahead is a crucial factor in peak performance. A good warm-up routine gives time to focus on the coming training or race. It’s also shown that an adequate warm-up reduces the RPE of a given effort, which can increase time to exhaustion at that intensity or improve the intensity you can maintain for a set duration.
- Temperature. The human body is only about 25% efficient when converting internal energy into external work. The remaining 75% is converted almost entirely into heat. So riding at 250 Watts means your producing 750W of heat energy. That’s the same heat output as a standard toaster!
Thankfully warmer muscles are actually more efficient and capable of producing greater force. Some studies have shown that efficiency can improve by 2-5% for every 1 degree Celcius above average body temperature. At warmer temperatures, the viscosity of your joints and ligaments decreases, meaning easier movement. We have almost all felt the opposite side of this when you are cold, and your joints feel “stiff.”
The transportation of oxygen from your blood to your muscles is dependent on two proteins, hemoglobin, and myoglobin. Hemoglobin is in your blood, while myoglobin is in your muscles. Myoglobin will take the oxygen away from the hemoglobin, thus moving oxygen from your blood into your muscles. As your blood temperature increases, the ability to transfer oxygen from hemoglobin to myoglobin improves. The same shift happens as your blood becomes more acidic, another side effect of exercising.
It turns out the term. “warm-up” is more accurate than you might have thought! A large portion of the physiological benefits of a warm-up comes from higher internal temperatures.
Unfortunately, above certain temperatures, critical systems start to work against you, most notably blood flow. You can read more about the impact of overheating here. The main point here is that if competing in hotter temperatures, you should consider reducing the duration and intensity of your standard warm-up routine.
As far as what’s the best warm-up routine for you? Personally, my go-to warm-up is the same one used in Team Scream, which is something that took me quite a few years to dial in. Now that you know a bit more about why a warm-up is important, you’ll have an easier time finding the right one for you. If you do find a routine that works well for you, don’t be afraid to sub it in for a SUF session’s warm-up