Since the first day of summer is just about a week away (June 21st), I wanted do a post about some (hopefully) helpful summer running tips related to adjusting your paces to account for the heat and humidity and staying hydrated.
Dew point is the best measurement of how humid the air feels because dew point is literally a measurement of how much humidity is in the air. Dew point is associated with relative humidity. A high relative humidity implies that the dew point is closer to the current air temperature. Relative humidity of 100% indicates the dew point is equal to the current temperature and that the air is maximally saturated with water. When the moisture content remains constant and temperature increases, relative humidity decreases.
We have a thermometer that shows us the temperature and relative humidity, so I was curious how to calculate the dew point.
I get geeked out over formulas and excel, so I have added a column to my training spreadsheet that calculates the dew point for me, after I enter the temperature and humidity. For any other dorks out there, the spreadsheet ready equation to solve for dew point (replace RH with the relative humidity and T with the temperature) is =243.04*(LN(RH/100)+((17.625*T)/(243.04+T)))/(17.625-LN(RH/100)-((17.625*T)/(243.04+T))).
And for anyone that wants an easier way, check out this calculator.
Once you have determined the dew point, you add the temperature to the dew point and adjust your pace as follows (adapted from my coach’s super informative blog post here).
Assume I would typically do my long run at 8 minute pace. Today (pictured above), the temperature is 89 degrees and the humidity is 76%. Using the calculator linked above, I figure out that the dew point is 80. I add the temperature and dew point together and get 169. This means that I need to adjust my pace by 6 to 8%. Based on the chart below, my goal pace in these conditions would be between 8:28 and 8:38 pace.
By adjusting your paces and expectations during the summer, you will shift your focus to the perceived effort of runs. It is important to recognize you will be slower than you hoped but effort is the most important factor and are still working at an equivalent effort of your unadjusted pace.
Know that we know how to adjust our paces, let’s talk about hydration.
Water is the main component of every cell and tissue in your body and if you don’t get enough, you’ll feel rundown and tired. It is estimated that under normal condition the average person loses 8 cups (2 liters or 64 ounces) of water per day. We sweat off several more cups during every hour of moderate exercise, even in normal conditions and much more so in the heat of the summer. The rate we lose sweat depends on a variety of factors including individual sweat rate, and the temperature, humidity, and length and intensity of your run. On a hot humid day an average sized person (110-165 lbs) can lose 1.6 to 2 liters of fluid, or 2.5% to 3.5% of body weight. So assuming we lose 2 pounds of water in sweat, we would need to replace at least 96 ounces or 12 cups per day.
It is very important that we adequately replace what we are losing. Some of this replacement comes naturally from foods that we eat, but we also need to make an intentional effort to take in a lot of water and healthy beverages. The best options that count towards our daily total are water, seltzer and flavored water. Other very good options are 100% fruit juices, lemonade, tomato and vegetable juices, and low-fat or skim milk. Good options include raw fruits and vegetables (see below). Other so-so options are decaffeinated soft drinks, decaffeinated coffee and yogurt. Caffeinated beverages and alcoholic drinks do not count towards our daily water total.
It’s also important to drink at regular intervals during your run at a rate that replaces fluid loss, so about 5-7 ounces of fluid every 15-20 minutes. This is the biggest struggle for me personally. But I am working on it! Try to select running routes that have water fountains along the way and carry a water bottle or drop a bottle along the route if possible.
The carbohydrates and sodium in sports drinks can also have beneficial effects. Carbohydrate solutions help maintain energy levels for racing by replacing depleted muscle glycogen stores, and sodium helps retain water, stimulates thirst and prevents low plasma sodium. Preserving our blood plasma volume is a key factor in sustaining optimal summer running pace, especially in events lasting more than 2 hours. Studies show that carbohydrates consumed immediately after and up to two hours after exercise enhance muscle glycogen restoration. This is most effective if ingested from fluid, as fluid is absorbed faster. Many studies also show that electrolyte balance is restored almost to pre exercise levels when an electrolyte beverage is drunk immediately after exercise.
I try to make it a habit to drink at least 16 ounces of water with 2 Nuun tablets immediately after my runs. I also try to drink G2 each day, especially if I am doing a double (two runs or two of any sort of exercise combinations, such as running and playing tennis). These are (currently) my favorite Nuun flavors.
I also try to make it a habit to incorporate a protein shake or smoothie as one of my meals (usually as breakfast post-run). Two of my favorite brands are Bolthouse Farms and Naked. There are three specific benefits to this. First, the shake counts towards my daily fluid intake. Second, these shakes are providing me with a very balanced mix of fats, carbohydrates and protein.
Third, taking in protein after running helps me recover more quickly. When you run, microtears occur in your tendons, muscles and other tissues throughout your body, but specifically in your legs. After your run, these microtears elevate your body’s demand for the amino acids found in protein; these acids help with tissue repair and rebuilding. Protein shakes provide a rich dose of these amino acids your body can absorb faster than through whole foods. This can help enhance the speed at which your body repairs those tears, reducing the recovery time needed after your run.
That’s all I’ve got for now. Anyone have any other good summer running tips? Please share!