You love running, but admittedly, you don’t have a set time in which you do it. Somedays, you run first thing in the morning because your schedule allows it, and on other days, the sun is setting and you’re only just lacing on your running shoes. Does when you run matter and is one time of day better than another?
You should schedule your runs when your core body temperature hits its peak, which is between 4 p.m. and 7 p.m. Running then is more advantageous for these reasons:
- Can more adequately process glucose and glycogen
- Nerve impulse speed is higher
- Could reduce your injury risk
- Stamina and energy are often greater
- Joints are more lubricated
- Muscles have more nutrition and oxygen
- Blood flow increases
If you’re not even aware of what your core body temperature is, then you’re not going to want to miss this article. In it, we’ll talk more about the importance of your core body temperature. We’ll also break down the pros and cons of morning versus nighttime running so you can plan your runs when you’re at your peak!
What Is Your Core Body Temperature?
When you’re feeling under the weather and you use a thermometer to check whether you have a fever, do you know what you’re really gauging? Your core body temperature.
Also referred to as your core temperature, core body temperature is simply the optimal temperature necessary to sustain life. This temperature encapsulates everything from your peripheral tissue to your liver. Without a consistent core body temperature, reactions cannot occur on an enzyme level.
So what is the average core body temperature? That’s 97.7 to 99.5 degrees Fahrenheit. Going back to the thermometer example if you’re feeling sick, you hope you get a temperature reading in that range, because it means you don’t have a fever.
A higher core body temperature can of course be caused by other factors besides illness, like physical activity as well. Once your core body temperature reaches 100.4 degrees, you may feel hot and start sweating. You’ll also be a little hungry and very thirsty. At 102.2 degrees, you’re breathless and your heart is beating very quickly. Your skin may be red and flushed, and you’re sweating a lot. You’re also quite tired.
What else causes your core body temperature to rise throughout the day? Your circadian rhythm. This internal clock runs on a cycle of 24 hours and manages your wakefulness, strength, reflexes, breathing capacity, hormones, and yes, your core body temperature.
If you often wake up at 5 a.m. to run, this is when your core temperature is lowest. Your temperature can drop by as much as 0.9 degrees, which is significant.
Why is your core body temperature lower first thing in the morning? Well, think of what you’re waking up to at 5 o’clock. It’s probably still dark out or the sun has just started to rise. The streets are quiet and empty as hardly anyone is awake. Without natural light, your internal clock is still running on snooze mode, so to speak.
As the sun comes up an hour or so later, your circadian rhythm kicks into gear. Your core body temperature will start rising, going up more and more as the sun gets stronger throughout the day. By 4 p.m. or 5 p.m., your core temperature is at its highest. It will stay that way until 6 p.m. or 7 p.m., right when the sun goes down and night begins.
Why Does Running at a High Core Body Temperature Matter?
The good news about that timeframe is that you’re likely done with work or soon will be if you have a standard nine-to-five job. That should free you up to run. Besides the convenience, why else should you run when your core body temperature has hit its peak?
As we touched on in the intro, you can reap a whole host of benefits that you don’t get when your core temperature is lower. Here’s an overview of those perks.
Your Body Better Processes Glucose and Glycogen
The first advantage of running at a higher core body temperature is how your body can more optimally process and break down glucose and glycogen. Glucose is a sugar source that your body produces; it also comes from the foods and drinks you consume. High-sugar and high-carb foods deliver the most glucose, but all food has glucose.
Your body takes this sugar and the glucose undergoes a process called glycogenesis. This conversion makes the glucose into glycogen, another sugar source that your body can use as energy. Your liver stores any leftover glycogen and will use it when your energy levels begin flagging.
When your body can break down glucose and glycogen effectively, you can retain your energy levels. Also, you can avoid a blood sugar spike or hyperglycemia.
Your Nerve Impulse Speed is Faster
Your nerve impulses are signals that travel through your nerve fibers to the brain. For example, your ability to see relies on nerve impulses. Your cone and rod cells in the eye receive light, which then activates nerve impulses to transport a signal to the optic nerve. The optic nerve delivers the signal to the brain, which tells you what you’re seeing.
This all happens lightning-fast, but what if your nerve impulse speed could be even faster? When your core body temperature is at its highest, your body is running on all cylinders. Thus, your already-fast nerve impulse speed could go up.
Your Injury Risk Decreases
With a high core temperature, you’re at a far lower risk of hypothermia and injuries related to cold temperatures. Also, again, since your circadian rhythm is operating at its strongest for the day and you’re feeling your best, you’ll be more alert, nimble, and agile. This could prevent your risk of injuries, keeping you running longer.
You May Have More Stamina and Energy
Your circadian rhythm dictates your sleep-wakefulness cycle. With more daylight, your internal clock is telling you that you should be awake. Since the circadian rhythm can also manage energy levels, you may feel your most energetic later in the afternoon before the sun goes down for the day.
This increase in energy can also act as a stamina boost. Try running during these three hours when your core temperature is higher. Go on a familiar route and time yourself. Then, wake up tomorrow morning and run at 5 a.m., following the same route. We’re sure your performance will be better when your core body temperature is at its peak.
Your Joints Are Lubricated
Another reason to plan your run at 4 p.m. or later is that your joints may be lubricated more than during other times of the day. Well-lubricated joints let you run without pain and can also contribute to your lower rate of injury.
Your Muscles Get More Nutrition and Oxygen
Your muscles require oxygen and nutrients to perform, especially during exercise. Your increased heart rate and breathing rate when you run are your muscles’ way of telling you what they need.
Fortunately, the rate of nutrition and oxygen delivery to the muscles when you run at peak core body temperature is greater than earlier in the day.
Your Blood Flow Is at Its Highest
The last benefit of running at core body temperature is your blood is flowing amply well. That makes it easy for your body to get oxygen, water, and nutrients, not to mention your heart’s blood supply stays healthy so it beats strong and proud.
What Are the Benefits of a Morning Run?
Although you know the best time to run to accommodate a higher core body temperature, you can’t always plan your run in that three-hour window of 4 p.m. to 7 p.m. That’s why, in the next two sections, we’ll cover the pros and cons of running in the morning versus running in the evening. This info should help you plan a running time and stick with it!
Start Your Day Feeling Productive
The first convincing reason to run in the morning is that you’ll feel super productive. You know those mornings when you drag yourself up, put some clothes on, sip some coffee, and drive on autopilot to work, right? You’re like a zombie, and all day, the feeling doesn’t go away. Those aren’t your best days, as you barely remember what you did or didn’t do.
When you energize yourself with a morning run, you’ll have checked off one major item on your to-do list. That could inspire you to keep up with your productivity for the rest of the day.
You Feel More Awake
Can you not even speak one sentence literately until you have at least a cup of coffee? Do you have to sip three or even four cups to feel alive enough to tackle your day? Rather than keep up your caffeine habit, try going on a daily run in the morning instead.
The endorphins you get from running act as a natural energy booster. You’ll walk into work with a pep in your step and cut down on your coffee drinking to boot. That’s a good habit, as you can reduce your caffeine-induced headaches, teeth staining, and risk of stomach ulcers.
Get It Out of the Way Early
Exercise is great for us, everyone knows that, but some days, it’s such a drag to get up and moving. You usually feel great once you’re out and running, but it’s everything leading up to that moment that’s hard.
When you start your morning with an invigorating run, you get it out of the way first thing. Now you have the whole rest of the day to spend productively without worrying about when you’ll squeeze in some time for your run.
Lower Blood Pressure
Is your blood pressure high or bordering on it? If you plan your morning runs between 6 a.m. and 8 a.m., you could decrease your systolic blood pressure, which is the top blood pressure number. The benefits can last into the day too.
This 2019 article from MedPage Today cites a study where older overweight and obese individuals did their daily exercise in the morning. They too reduced their blood pressure through their fitness regimen.
The runner’s high is not just a myth, but rather, a very real sensation that some runners experience. This feeling is a combination of the natural pain-blocking that adrenaline brings as well as lessened anxiety and heightened endorphins, which can produce euphoria.
The happiness you get from a runner’s high may last longer in some people than others, but endorphins can continue boosting your mood for upwards of 24 hours. You won’t even mind that it’s a Monday.
Good Time for Building Muscle
If you’re trying to pack on more muscle, one ideal time to plan your runs is in the morning. The hours of 5:30 a.m. to 8 a.m. are when testosterone levels are at their highest. Both men and women have testosterone, although men have higher quantities than women.
Testosterone can generate more muscle mass, leading to your muscles looking large and strong. Make sure you pack on the protein when you eat after your run to feed your burgeoning muscles!
What Are the Downsides of a Morning Run?
As great as running in the morning can be, it’s not all sunshine and rainbows. Here are some downsides to be aware of.
It’s Tough to Get out of Bed So Early
If you’re in a constant battle with the snooze alarm in the morning, then you especially might not feel much motivation to get out of bed for a run. Considering you often have to wake up an hour or two earlier than you usually do for work, you have to choose exercise over sleep, and that’s a hard choice to make.
You May Feel Sluggish and Underperform
Even if you do get out of bed and barely put your running shoes on the right feet, you’re not running at your best. You feel slower than usual, and your numbers don’t compare to when you run later in the day.
This doesn’t happen for everyone, but some runners might find that getting up, going through their day, eating a few meals, and then running later in the day puts them in a better mental and physical frame to do well.
Your Rate for Injury May Be Higher
When you’re bleary-eyed and fighting back fatigue already, you’re likely not paying attention to your surroundings. Combine that with your poor performance and you could trip over yourself or a hazard on the road and end up hurt.
Even if you are more alert, with your core body temperature lower in the morning, you’re not getting as much oxygen. This leaves your muscles stiff, so all it takes is one wrong move and you’ve strained a muscle.
You Could Feel Tired for the Rest of the Day
If you spend what energy you have first thing in the morning, you might find that you have none left to give. This is a problem considering you have to spend the day at work instead of in bed. You could begin dozing off during your conference call or in front of your computer, getting in trouble with your boss.
What Are the Benefits of an Evening Run?
You know that the peak running period is between 4 p.m. and 7 p.m., but what if you run a little later in the day? What benefits might you enjoy? Here’s what you need to know.
You Have More Time to Run Than in the Morning
Running before work is a bit stressful, as you need to plan every facet of your morning. That includes mealtime, the route you’ll run, how long it will take you to complete your run, your shower time, your wardrobe, and maybe even your breakfast before you’re out the door.
When you run after work, you don’t have any pressing obligations. You can take your time, ensuring you fuel up, get dressed well, and stretch before you run.
Lower Blood Pressure
We mentioned that you can lower your blood pressure with a morning run, and it turns out the same is true of an evening run as well. Try to plan your runs at around 7 p.m. for the most noticeable effects on your systolic blood pressure.
You Could Reset Your Circadian Rhythm
Did you used to work a night shift and you recently switched to days? Perhaps you’re a jetsetter and you’ve been flying here, there, and everywhere. In both cases, more than likely, your circadian rhythm is all out of sorts.
To reset it, start running in the evening. This 2017 publication of the journal Acta Cardiologica Sinica states that “exercise is a strong entrainment signal for mammalian circadian clock.” Granted, it may take a few nights of running before your internal clock feels more normal, but it will happen.
You’re Less Injury-Prone
Since your core body temperature hit its peak or it has just reached its highest point, your body is operating incredibly well in the evening. Your muscles are fed with oxygen, your joints are lubricated, and your mind feels clear. You can see road hazards and avoid them, and since your muscles aren’t nearly as stiff as they are in the morning, you’re less prone to overstretching and hurting them as you run.
You Have More Energy
As we discussed earlier, running when your core temperature is higher will energize you, inspiring you to reach new milestones and break your own running records.
You Can Build More Muscle
Besides the morning, an even more ideal time to run if you want bigger muscles is in the evening. While testosterone levels are indeed higher in the morning, so too is cortisol, a stress hormone that can inhibit testosterone functioning. In the evening, your cortisol levels are lower, so even if you don’t have as much testosterone, what your body does have it used well.
What Are the Downsides of an Evening Run?
Evening runs also have a few problems you can’t discount. Make sure you keep these downsides in mind.
Chews into Your Personal Time
Most people who work a nine-to-five plan their personal time in the evening, not the morning. When you run in the morning, as much of a pain as it can sometimes be, you free up your entire evening. Running at night might be more leisurely, but when you get home, the rest of your evening is cut short. That doesn’t give you a lot of time to relax before you get up for work again the next day. You could become rundown before you know it.
Sure, in the morning, you might have foggy, cloudy conditions, but it’s brighter out so you can typically see well. Once the sun goes down and darkness falls, your visibility is reduced. In the summer, you can run in the evening no problem, as it’s still bright out. For the rest of the year though, you’re running in the dark, and that can be dangerous.
You May Overeat if You’re Hungry After a Run
With no post-run obligations in the evening, you can pay more attention to your hunger cues. That may cause you to make a huge dinner or eat an extra snack or two after your run. Doing this often enough can negate your running progress and pack the extra pounds on.
You Could Ruin Your Sleeping Habits if You Run Too Late
You also want to be careful when you schedule your evening run. If you’re out a few hours before bedtime, the adrenaline and endorphins can still be going strong by the time you retire for the night. You’ll find it very difficult to sleep.
If you’re stuck between the thought of running in the morning versus running at night, the best time to plan your run is when your core body temperature is highest. This window is from 4 p.m. to 7 p.m. At this time, your circadian rhythm increases your energy, muscle performance, and stamina so you can run better. We hope this article helps you figure out a run schedule that works for your lifestyle and doesn’t hamper your running performance. Good luck!