Author: Brianna Swyden

How serious is it? Temperatures over 100° Fahrenheit or even temperatures in the 80°s with high humidity can cause a dangerous heat index that can be hard on the heart. Recent research published in the journal Circulation found that when temperatures reach extremes of 109° or more—something that’s not uncommon in parts of Arizona, Florida, Nevada, and Texas—the number of deaths from cardiovascular disease may double or triple.² Another study, presented at the American Stroke Association’s International Stroke Conference suggests that the more temperatures fluctuate during the summer, the more severe strokes may become.³

How Hot Weather Affects the Heart

Because the body has to work harder than normal to maintain a healthy temperature in hot weather, your blood pressure and heart rate can go up while your blood volume can go down due to dehydration. Here’s what happens: In hot weather, the body needs to cool down. This causes the blood vessels in your skin to dilate, leading to a drop in blood pressure.² The heart then works harder to maintain blood pressure by pumping more forcefully and faster, potentially increasing your risk of experiencing a cardiovascular event.⁴

Dehydration due to the heat makes matters even worse. Sweating when the weather is hot can lead to fluid loss, which can reduce blood volume and further stress the heart. ⁴  And that’s especially true for people who play sports or exercise in the heat. Heat stress—which occurs when the body can’t regulate its core temperature—can also cause inflammation and damage to blood vessels, which can worsen existing heart conditions.⁵ Even if you aren’t active when outdoors, hot weather can worsen air quality, leading to increased exposure to air pollutants that can exacerbate heart disease and may increase the risk of dying from a heart attack.⁶

Are You at Higher Risk? 

If you already suffer from a pre-existing heart condition, you’re even more vulnerable to these effects. This is especially true for anyone with heart failure or coronary artery disease. Studies show that the uptick in heatwaves are a significant factor in cardiovascular deaths.⁷ Those living with certain heart conditions or risk factors like high blood pressure and are taking certain medications like beta blockers or diuretics may be at particularly high risk during a heatwave.^8,9

Age also plays a significant role. This is because, as people age, their ability to regulate their body temperature and cope with heat stress decreases.¹⁰ Even if you haven’t reached your senior years, recent studies suggest that  living in a hotter environment can accelerate your biological aging just as much as smoking does.¹¹

Tips to Protect Your Heart in Hot Weather 

Fortunately, whether you live in Phoenix or Miami or your area is just suffering through a random heatwave, there are steps you can take to protect yourself from the heat.

1. Stay hydrated. Drinking plenty of water helps to regulate your temperature. It also helps your heart pump more easily and keeps all your organs functioning properly. Remember to drink before you are thirsty, and avoid alcohol and caffeinated beverages, which can dehydrate the body.

2. Keep cool. If you don’t have access to air conditioning, a cold compress applied to your pulse points—areas where your veins are closest to your skin’s surface, such as your wrists, neck, temples and armpits—can help you cool down.

3. Be mindful of exercise. If exercising outdoors, choose cooler times of the day and ensure you’re well-hydrated.

4. Know the warning signs of heat distress. Spending too much time in extreme heat may lead to heat exhaustion and, in turn, heatstroke, two serious heat-related illnesses in which your body can’t control its temperature.

• • Heat exhaustion symptoms. Heavy sweating, nausea or vomiting, muscle cramps, tiredness, dizziness and fainting. Treatment: Move to a cool place, loosen clothing, use cold compresses, sip cool (not cold) water. If symptoms persist, call 911.
  • Heatstroke symptoms. Fever of 104 degrees or more, severe headache, behavioral changes, confusion, hot/red skin, no sweating, rapid heartbeat and loss of consciousness. Treatment: Heatstroke is a life-threatening medical emergency. Call 911 immediately. Quickly move the individual to a cooler place, use cold compresses, do not give anything to drink.

5. Timing is everything. Avoid being outdoors during the hottest times of the day, when the sun is at its strongest and temps are at their highest—typically between 11:00 a.m. and 1:00 p.m.

6. Be aware of air pollution. Avoid outdoor activities that could expose you to high levels of air pollution during heat events.

7. Dress right. Wear loose, light-colored clothing (to help reflect heat) that is made of a lightweight, breathable fabric like cotton. Add a wide-brimmed hat, sunglasses, and sunscreen.

8. Take supplemental Aged Garlic Extract (AGE). Research shows that AGE can protect your cardiovascular system in several ways, even in the heat. Clinical trials show that AGE reduces blood pressure in patients with uncontrolled hypertension as well as common blood pressure medications.¹²  It’s also been shown to lower cholesterol, prevent the buildup of plaque and calcium in arteries, and even improve circulation in the skin.^13,14,15,16

Being prepared when the dog days of summer hit will not only keep you comfortable in the heat, but following these tips when the temperature rises might even save your life!

What is VO₂ max?

VO₂ max is the maximum amount of oxygen your body can utilize during intense exercise. And it’s the best measurement of cardiorespiratory fitness, reflecting how efficiently your heart and lungs deliver oxygen to your working muscles. VO₂ max also tells you how well your muscles can use that oxygen to generate energy.

The best way to measure your VO₂ max is in a laboratory setting. A tightly fitted mask or breathing snorkel is worn and connects to a bulky oxygen reading machine as the athlete exercises at full effort while working out on a treadmill, stationary bike, or rowing machine.

This machine then calculates your VO₂ max based on oxygen delivery (air exchange in the lungs, pumping power of your heart, and arterial blood flow to your muscles) and also oxygen demand by the tissues in your body.

Mitochondria—those little energy factories found in every one of your cells—are a major factor in the oxygen delivery portion of VO₂ max (mitochondria power the heart) and in the oxygen demand (how many mitochondria are in the muscles). In less conditioned athletes, VO₂ max tends to be mostly limited by oxygen demand (less muscle mass and fewer mitochondria in untrained people). Elite athletes, on the other hand, have more muscle mass and considerably more mitochondria. So, while you can use this test to see how efficiently your body uses oxygen while you exercise, VO₂ max is actually an estimate of your mitochondrial density.²

Having your VO₂ max tested in a lab is the most accurate way to assess your fitness level, but it does come at a cost. Depending on your area and the facilities available, expect to spend anywhere from $100 to $250.³ However, you can also do a DIY test called the Cooper test, that can give you a good idea of where you stand fitness-wise. Also known as the 12-minute run test, the Cooper test is designed to estimate a person’s cardiovascular endurance and VO2 max. It involves running or walking as far as possible in 12 minutes. The distance covered is then used to estimate an individual’s aerobic fitness level.⁴

To complete a Cooper test, you should walk or run, without interruptions, for 12 minutes. You can do this on either a treadmill or running track, and you should aim to keep the same pace throughout the test. After 12 minutes, note the total distance you’ve covered. To calculate VO₂ max from the distance covered in 12 minutes, enter your distance in meters (D) into the following formula: VO₂ max = (D – 504)/ 45. If that feels a bit too complicated, you can simply use an online calculator like this one that gives you the option to use kilometers or miles.

What the Numbers Mean

Here are two charts that can help you figure out your cardiorespiratory fitness levels base on your VO₂ max results—one for men and one for women—and your age.⁵

MEN	Age
FITNESS LEVEL	13-19	20-29	30-39	40-49	50-59
Very weak	< 2090	< 1960	< 1900	< 1830	< 1660
Weak	2090-2200	1960-2110	1900-2090	1830-1990	1660-1870
Average	2210-2510	2120-2400	2100-2400	2000-2240	1880-2090
Good	2520-2770	2410-2640	2410-2510	2250-2460	2100-2320
Excellent	> 2780	> 2650	> 2520	> 2470	> 2330

 

WOMEN	Age
FITNESS LEVEL	13-19	20-29	30-39	40-49	50-59
Very weak	< 1610	< 1550	< 1510	< 1420	< 1350
Weak	1610-1900	1550-1790	1510-1690	1420-1580	1350-1500
Average	1910-2080	1800-1970	1700-1960	1590-1790	1510-1690
Good	2090-2300	1980-2160	1970-2080	1880-2000	1700-1900
Excellent	2310-2430	> 2170	> 2090	> 2010	> 1910

 

How to Improve Your VO₂ max

If your VO₂ max or Cooper test results could be better, don’t despair. You can improve your cardiorespiratory fitness with training. Focus on regular aerobic exercise, particularly

high-intensity interval training (HIIT), as well as endurance training. HIIT involves short bursts of intense exercise followed by brief recovery periods, while endurance training involves consistently pushing your endurance limits. Switching up your workouts by incorporating different types of aerobic activities (e.g., running, cycling, swimming) can help prevent plateaus and keep your body challenged.

Maintaining a healthy weight can indirectly improve your VO₂ max as well, but it’s important to distinguish between gains due to training and those solely from weight loss, according to Harvard Health. And don’t forget to prioritize your recovery through adequate sleep.

Consider Supplementing

There are a number of supplements reputed to enhance exercise performance, however few have rigorous clinical evidence supporting their effectiveness. That said, there are several that studies suggest may improve VO₂ max. Here are three with scientific credibility that you may want to consider adding to your workout routine.

Aged Garlic Extract (AGE) was recently shown to provide long-term performance benefits for the long distance athlete. In a double-blind, parallel, randomized study involving 75 middle-aged endurance athletes, AGE was found to boost VO₂ max, increase arterial flexibility and aerobic power, decrease fatigue, and reduce post-workout recovery time. These benefits weren’t seen in those taking the placebo. The participants taking AGE also had a lower risk of cardiovascular disease compared to those in the placebo group.⁶

Earlier research found that AGE improves blood pressure and arterial stiffness, effectively “rejuvenating” the arteries that carry nutrient- and oxygen-rich blood to all the tissues and organs in the body, including muscles, thanks to its active compound S-allylcysteine (SAC).⁷ SAC is formed by the enzymatic conversion of gamma-glutamyl-S-allylcysteine (GSAC) when garlic undergoes the aging process. The result is a powerful antioxidant and anti-inflammatory compound that provides a variety of heart healthy benefits that can improve your fitness level and exercise capacity.

Ashwagandha is a popular adaptogen that some studies suggest can enhance VO₂ max. During one meta-analysis, a group of Spanish researchers systematically reviewed nine studies and concluded that a daily dose of ashwagandha improved VO₂ max in both athletes and healthy non-athletic people.⁸  This calming herb has also been found to enhance muscle strength and coordination as well as cardiorespiratory endurance.⁹

Rhodiola is another adaptogen that may help increase exercise performance. Research suggests that rhodiola can increase physical performance and endurance in professional athletes while helping to build new muscle tissue.¹⁰ There’s also some evidence that, when taken 60 minutes before a workout, rhodiola may improve time to exhaustion and time trial performance, which could indirectly impact VO₂ max.¹¹

If you’re an endurance athlete looking to up your game, knowing your VO₂ max can provide an excellent tool to track your progress. If your VO₂ max and cardiorespiratory fitness could use a boost, try focusing on HIIT and endurance workouts, maintaining a healthy weight and getting a sufficient amount of sleep. You can also take your performance to the next level with clinically proven supplements like aged garlic extract.

Coenzyme Q10, more commonly known as CoQ10, is a fat-soluble, energy-producing micronutrient that’s found in nearly all of your tissues, with some of the greatest concentrations found in your heart.¹ And that matters because this hard-working organ needs lots of energy to function at its best.

CoQ10 Loves Your Heart

Research suggests that CoQ10 acts like a valentine for your heart. It improves heart function, reduces the risk of heart disease, and helps manage conditions like congestive heart failure by warding off oxidative stress and supporting energy production within heart cells.² 

This multi-talented molecule neutralizes harmful free radicals by contributing an electron to damaged molecules that are missing one (normal molecules have two electrons).³ This, in turn, helps to prevent oxidative damage and inflammation—two factors that contribute to the development of atherosclerosis.⁴

This powerful antioxidant also helps to generate energy inside your mitochondria (structures inside your cells that act like little energy factories) by making another antioxidant called adenosine triphosphosphate (ATP). ATP is the primary energy source for the heart. In fact, some experts have even dubbed CoQ10 “the body’s spark plug.” The production of ATP directly impacts the heart’s ability to effectively pump blood and maintain adequate cardiac output. If ATP levels drop, so does your heart’s ability to contract properly. That can lead to reduced cardiac output and ultimately contribute to heart failure.⁵

Lagging Levels

 Although CoQ10 is vital to a healthy cardiovascular system, the body’s production of this critical molecule naturally falls as we age. And that can increase oxidative stress in those over age 60.⁶   Another common reason for low levels is the use of statin drugs. This happens because these cholesterol-lowering medications decrease LDL cholesterol levels, which is the main transporter of CoQ10 in the blood.⁷  Whether you’re taking a statin or are simply growing older, low levels can have a significant impact on your cardiovascular system. Indeed, three out of four patients with heart diseases have subpar CoQ10. ²  Fortunately, supplementing with CoQ10 can help restore your levels.

What the Science Says

 How effective are CoQ10 supplements for cardiovascular health?  Multiple studies show that supplementation can help those with congestive heart failure, especially when paired with conventional treatment. In an Italian study of more than 2,600 people with heart failure, adding a daily dose of CoQ10 to their standard treatment significantly improved symptoms like swelling and heart palpitations.⁸ And a review of 14 randomized clinical trials involving 2,149 heart failure patients also found that those taking CoQ10 had less chance of dying prematurely. They also had a higher tolerance for exercise compared to the participants taking a placebo.⁹ That’s a big deal since regular exercise is one of the most effective ways to support a healthy heart.

CoQ10 has also been found to promote healthier blood pressure, due largely to its antioxidant activity. It’s so effective that one randomized, double-blind, placebo-controlled study conducted by the Department of Veterans Affairs found that supplementing with CoQ10 for three months effectively reduced systolic blood pressure.¹⁰ Australian researchers noted even better results after reviewing 12 clinical trials of people with hypertension. In their analysis, they found that supplementing with CoQ10 lowered systolic blood pressure by as much as 17 mm Hg and diastolic blood pressure by up to 10 mm Hg without any significant side effects.¹¹

Better Together

As good as CoQ10 is on its own, it’s even better when taken with Aged Garlic Extract (AGE). This dynamic duo has been shown to reduce inflammation, improve vascular elasticity and endothelial function, and help prevent the progression of coronary atherosclerosis. In one groundbreaking study conducted at the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, researchers looked at a group of 65 firefighters who were at an elevated risk of cardiovascular disease. Firefighters, who work in a highly stressful environment, have triple the risk of having a heart attack or other adverse cardiovascular event compared to the general population.

All of the firefighters underwent testing to determine their risk by measuring pulse-wave velocity (which evaluates the elasticity of arteries) and digital thermal monitoring (which measures endothelial function). The researchers also took an earlier study into account that measured each firefighters’ plaque buildup and the amount of calcium deposits in their coronary arteries, as well as systemic inflammation—all factors that can increase the risk of heart attack.

Once their risk factors were determined, the firefighters were randomly assigned to either a daily supplement containing AGE and CoQ10 or a placebo. After one year, the researchers found that, compared to the placebo, the AGE/CoQ10 combo improved both vascular elasticity and endothelial function. That, in turn, helped lower the odds of future plaque buildup and reduced the firefighter’s risk of a future heart attack or stroke.^12,13

Fortunately, you don’t need to have a high-pressure job like firefighting to benefit from AGE and CoQ10. If you’re at an increased risk of atherosclerosis, heart failure, or high blood pressure—or if you’re taking a statin drug—supplementing with these two powerhouse nutrients can help your entire cardiovascular system keep the beat for a lifetime.

Engaging in regular exercise is the best way to support cardiovascular fitness and reduce the risk of a future heart attack or stroke. The problem is, only about 22 percent of Americans get the recommended amount of exercise each week. Living a sedentary lifestyle can increase the risk of high blood pressure by 30 to 50 percent and is a significant risk factor for all forms of cardiovascular disease.¹ In fact, inactivity is just as harmful to your cardiovascular system as smoking.² But adding exercise to your daily routine can reduce or even prevent these risk factors.

How Exercise Benefits Your Cardiovascular System

Regular exercise can have a huge impact on your overall cardiovascular health. It can help protect against that first heart attack or stroke, reduce the risk of having another cardiac event, and even help patients recover from coronary surgery. ¹ More specifically, exercise can:

• Reduce blood pressure
• Lower LDL (bad) cholesterol
• Increase HDL (good) cholesterol
• Improve circulation by increasing nitric oxide
• Help reduce plaque in arteries
• Lessen inflammation
• Prevent blood clots
• Foster a healthier weight ^3,4,5

Measuring Your Cardiovascular Fitness

One of the best ways to assess your cardiovascular fitness is by measuring VO₂max (volume-maximal-oxygen-consumption).⁶ Technically, VO₂max refers to the maximum amount of oxygen that a person can utilize during intense exercise. To put it in simpler terms, VO2 max shows how well your heart pushes blood to your muscles and how efficiently your muscles can use  that oxygen to power your workout.

You can find out your VO2 max number by performing a cardiopulmonary exercise test at your doctor’s office or an exercise medicine lab. Typically, you’ll wear a mask over your face to record your oxygen consumption and carbon dioxide production while running on a treadmill, riding a bike, or doing some other form of cardiovascular task. While that can give you an accurate reading, insurance likely won’t cover a VO2 max test. However, some fitness trackers can estimate your VO2 max to give you an idea of how fit you are.

The Best Types of Exercise for Your Heart

Being physically active is one of the best ways to improve your cardiovascular health and your VO2 max. In fact, regular exercise is one of the most effective ways to strengthen the heart muscle and improve your entire cardiovascular system. But what kind of exercise is best for your heart? Studies show that a combination of aerobic exercise and strength training is the most effective way to improve your overall cardiovascular health.^7,8

Aerobic exercise is defined as any exercise that increases your heart rate and your breathing rate while using your large muscle groups in a rhythmic and repetitive way. Examples of aerobic exercise include cycling, dancing, hiking, jogging, swimming, and walking. Often called “cardio,” aerobic exercise can help improve your heart health, burn fat, and increase your stamina and strength. It can also reduce your risk of high blood pressure, diabetes, stroke, obesity, and heart disease.^9,10

Strength training, on the other hand, improves blood pressure, cholesterol, blood sugar, and body composition—and it’s especially beneficial for older adults. As a bonus, it also has a positive effect on non-traditional cardiovascular risk factors like cardiorespiratory fitness, endothelial function, and well-being.¹¹ Examples include working out with free weights, weight machines, resistance bands, or your own body weight (think push-ups, squats, and lunges).

Combining strength training with aerobic exercise may offer more benefit in reducing certain cardiovascular disease risk factors, such as obesity, diabetes, and high cholesterol, compared to resistance training or aerobic training alone. ⁸

How Much Exercise is Enough?

According to the Centers for Disease Control and Prevention, adults should get a minimum of 150 minutes of aerobic exercise plus two non-consecutive days of strength training per week.¹² But new evidence published in the journal Circulation shows that doubling or even quadrupling the minimum amount the guidelines suggest confer even more health benefits. This study, which analyzed 116,221 adults, found that those who exercised two to four times more than the minimum recommendation lowered their risk of dying from any cause by 31 percent, up from just 21 percent for those meeting the minimum. And those who exercised more were also as much as 33 percent less likely to die from cardiovascular disease compared to 25 percent among those in the minimal exercise group.¹³

If getting even the minimal recommended amount of exercise feels daunting, take heart. Using an app to gamify your workouts, taking a group exercise class, or recruiting an exercise buddy can help you stay motivated. And don’t forget your everyday activities! Cleaning, gardening, washing the car, or chasing after the kids also count as exercise.

Stack These Heart Healthy Habits on Top of Your Workouts

Maximize the benefits of exercise with a few healthy lifestyle hacks. Indeed, the following changes are proven to boost heart health, especially when paired with regular workouts.

Level up your food choices. Research shows that a diet high in ultra-processed food, especially sugary drinks, and processed meats like hot dogs and lunch meat, increase the risk of cardiovascular disease.¹⁴ Trade in these unhealthy foods for a Mediterranean-style diet rich in fruits, vegetables, fish, nuts, whole grains, and healthy fats like extra virgin olive oil.¹⁵

Get a handle on stress. Exercise itself can help lower stress. Adding relaxation activities like meditation or yoga can help you chill out even more and that can have a beneficial effect on your cardiovascular system.¹⁶

Up your antioxidants. Science has confirmed that antioxidants lower oxidative stress during exercise and improve post-exercise recovery.¹⁷ This matters because oxidative stress can trigger inflammation, encourage the development of atherosclerosis, set the stage for high blood pressure, contribute to cardiac remodeling, and delay post-workout recovery. But not all antioxidants have the same heart healthy benefits. Emerging evidence suggests that antioxidant-rich Aged Garlic Extract (AGE) not only reduces oxidative stress, it also lowers blood pressure, and improves cholesterol, arterial stiffness, and aerobic fitness in middle-aged recreational athletes.^18,19 Other research suggests that supplementing with AGE can lessen fatigue and foster faster recovery after a workout.²⁰

Adding exercise to your daily routine is among the very best ways to maintain and improve  a healthy cardiovascular system. As a bonus, engaging in regular physical activity—whether in the gym, in nature, or around the house—can keep you strong, energized, and active for a lifetime.