High-Intensity Exercise or Endurance? For the Most Health Benefits, Do Both

HIIT and SIT workouts can get you fit fast, but for lasting health benefits, you need moderate-intensity exercise, too.

By ​Selene Yeager            

    Recent research in the journal Medicine & Science in Sports & Exercise found that high-intensity exercise (HIIE) was more effective for improving aerobic fitness and cardiovascular health, and moderate-intensity continuous training (MICT) was better for long-term blood sugar control.

    This study adds to recent evidence that one exercise intensity is not superior to another, and there are good reasons to do both for overall health benefits.

High-intensity interval exercise (HIIE) has been the darling of the fitness world for the better part of the past decade, because these quick, hard intervals can help you get fit fast. But a recent meta-analysis published in Medicine & Science in Sports & Exercise is a good reminder that for long term metabolic health benefits, you need moderate-intensity endurance training, too.

As a refresher, a tall stack of studies shows that high-intensity exercise, such as high-intensity interval training (near-maximum efforts) and sprint-interval training (“all out” efforts)—brief bursts of hard exercise followed by a short period of rest—is a time-efficient way to boost your aerobic and anaerobic fitness, making you stronger and faster on the bike. HIIE also has myriad health benefits, such as improving insulin sensitivity, improving brain function, lowering your risk of cancer, and burning fat while helping you maintain lean muscle mass.

But there’s a catch. The health benefits of high-intensity training can be transient. Research shows that some of the favorable effects, such as improved blood sugar control, can drop back to previous levels 24 hours after exercise. And you’re only supposed to do a HIIT or SIT session two to three days a week—too much intensity increases inflammation in the body, which is bad for performance and health.

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So what’s the best approach for long-term health improvement as well as fitness gains right now? A team of German researchers decided to pore through the current literature to examine the specific cardiovascular and metabolic benefits of both.

The scientists analyzed the results of 55 studies that examined the effects of HIIE and moderate-intensity continuous training (MICT) on seven different health outcomes:

    Cardiovascular health (measured by endothelial function, or how well blood vessels respond to exercise demands)

    Body composition

    Blood pressure

    Blood lipids

    Inflammation

    Insulin and glucose (blood sugar) metabolism.

The meta-analysis found HIIE was more effective for improving both aerobic fitness and cardiovascular health. For long-term blood sugar control, however, moderate, steady-state exercise was superior.

Everything else was pretty much a draw, though there appeared to be some benefits unique to different age groups. For instance, HIIE had benefits for people ages 30 to 50 for reducing diastolic blood pressure and for those who already had elevated blood pressure. And SIT appeared to be particularly effective for lowering LDL cholesterol levels.

It’s also important to note that, though it appears that HIIE may have some advantages for fitness, these studies alone aren’t enough to draw that conclusion, says exercise training researcher Jamie Burr, Ph.D., associate professor at University of Guelph, HHNS, Ontario.

“It is important to note that the average study duration was only 9 +/- 5 weeks,” Burr says. “It begs the question as to whether HIIT is actually superior overall, or just superior at stimulating change quickly.”

The take-home message that is emerging from this analysis—as well as from a recent study, which also reported unique benefits from both types of exercise—is that there’s no one “best” way to workout. Making room for both high-intensity and steady-state endurance activity not only makes you a more well-rounded athlete, but also provides a greater spectrum of health benefits.

​Selene Yeager “The Fit Chick” Selene Yeager is a top-selling professional health and fitness writer who lives what she writes as a NASM certified personal trainer, USA Cycling certified coach, Pn1 certified nutrition coach, pro licensed off road racer, and All-American Ironman triathlete.

A Single Session of Moderate-Intensity Exercise Benefits Your Cells in a Big Way

It may stimulate your mitochondria, which is responsible for turning fuel into energy. Here’s why that’s important.

By Elizabeth Millard

Apr 6, 2021

Jason Frank

• One session of moderate aerobic exercise can charge up your cells, according to a recent study in Medicine & Science in Sports & Exercise.
• Exercise may stimulate small changes in mitochondria—which is responsible for turning fuels like fats and sugar into energy—and when stacked up over time, could increase efficiency in fuel metabolism.

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If you’re starting an exercise routine for the first time or getting back into it after a winter break (or, let’s face it, a pandemic year), here’s some good news to keep you motivated: Just one session of moderate aerobic exercise can charge up your cells, according to a recent study in Medicine & Science in Sports & Exercise.

Researchers recruited 15 women and men in their 20s and 30s, who reported being generally sedentary, and had them ride a stationary bike for an hour at a moderate intensity.

Muscle biopsies done before and then 15 minutes after showed a significant post-exercise difference in cell mitochondria—the part of the cell responsible for turning fuels like fats and sugar into energy (think of it as the calorie furnace for the body). After cycling, participants’ mitochondria burned about 12 to 13 percent more fat and 14 to 17 percent more sugar.

“Exercise stimulates many aspects of metabolism,” lead author Matt Robinson, Ph.D., assistant professor in the College of Public Health and Human Sciences at Oregon State University, told Runner’s World. “We wanted to investigate the short-term effects of exercise directly on skeletal muscle mitochondria, which are the main site of fuel metabolism.”

Although the effects were mild with just one session, he added, they were consistent. That means a single session of exercise may stimulate small changes in mitochondria, and when stacked up over time, could increase efficiency in fuel metabolism.

One limitation here is the small participant number and inclusion of younger people only. However, it’s very likely that the result would be similar across age ranges, added study co-author Sean Newsom, Ph.D., assistant professor in the College of Public Health and Human Sciences at Oregon State University.

“People of all ages can increase mitochondrial fuel metabolism with aerobic training,” he told Runner’s World. “Findings like these are very encouraging, particularly for aging populations that often have declines in mitochondria.”

In other words, younger people may appreciate the calorie-burning effects of improved mitochondria function, but those who are older may benefit even more. As we age, the accumulation of cell damage—prompted by everything from illness to slower cell turnover —can cause a decline in mitochondrial function, previous research has noted.

Does that mean one session of riding prompts your cells to perk up enough to slow the aging process? Maybe not, but as you increase those sessions, you could be giving your cell function a healthy boost.

Elizabeth Millard Elizabeth Millard is a freelance writer focusing on health, wellness, fitness, and food. 

Want to Improve Your Memory? Just 15 Minutes on the Bike Is Enough

New research suggests it doesn't take much to kickstart better brain health.

 

By Elizabeth Millard

skaman306Getty Images

• According to new research in the journal Scientific Reports, just 15 minutes of high-intensity cycling could help improve your memory.
• Parts of the brain that are associated with memory and motor processes are fired up after a more intense cycling session.

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If you want to improve your brain power to learn a new skill or if you just want a memory boost, a recent study suggests a quick 15-minute ride could help—especially if you up the intensity.

Published in the journal Scientific Reports, researchers recruited 15 young, healthy men who didn’t exercise regularly, and had them perform memory tests on three occasions: One was after 30 minutes of moderate cycling, another after 15 minutes of intensive cycling—defined as 80 percent of their maximum heart rate—and the third after a rest period.

The memory test was a simple one, with participants pressing buttons related to a pattern of dots appearing on the screen. Because there was a clear sequence, it allowed researchers to evaluate how movements were learned, according to lead study author Blanca Marin Bosch, Ph.D.(c), of the Department of Neuroscience at the University of Geneva in Switzerland.

“This measured motor learning, much like when you first learn to type on a keyboard, for example,” she told Bicycling. “In this case, the higher intensity resulted in better memory performance.”

Because researchers also did blood tests and functional MRI scans, they were able to determine that the hippocampus and the caudate nucleus—parts of the brain associated with memory and motor processes—were fired up after the more intense cycling session. In a previous study, the same research team showed moderate-intensity exercise can have an effect as well, but that works best on associative memory, said Bosch. That’s the type used more for recall than learning, and it allows you to make connections between separate items. For example, remembering someone’s name when you see their face.

“The takeaway here is that not all forms of memory use the same mechanisms and pathways in the brain, and exercise of different intensities can be useful for different functions related to memory,” Bosch said.

The current study has limitations—it featured a small number of participants, included men only, and had a short timeframe. But the association between physical activity and memory performance is well established in previous research, and other recent studies have suggested intensity can play a major role.

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For example, a 2019 study found that high-intensity workouts improved memory so much in older study participants that researchers suggested they could be used as a main intervention for reducing dementia risk.

A similar study on older adults, published earlier this year, found that high-intensity interval training—which often comes in around the 15- to 20-minute mark for a session—produced significant memory performance, even for generally inactive participants.

So hopping on your bike—even if you have a limited amount of time in your schedule—can result in some pretty solid benefits for your brain.

Elizabeth Millard Elizabeth Millard is a freelance writer focusing on health, wellness, fitness, and food. 

Saturated Fat Is Not Your Heart’s Enemy

A research review finds no evidence for limiting whole foods that are high in saturated fat, contrary to popular belief.

By Selene Yeager

Jun 23, 2020

 

• Limiting foods rich in dietary saturated fatty acids has no benefit for heart health or overall risk of death, according to a study published in the Journal of American College of Cardiology.
• Saturated fat does increase LDL cholesterol, but generally the large, “fluffy” LDL particles that are not considered harmful, rather than the small, dense LDL particles that raise your risk of heart disease.
• Focusing on eating whole foods rather than eliminating or limiting fat is a preferable health strategy, according to the researchers.

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Eating a diet that includes whole foods rich in saturated fats won’t raise your risk for cardiovascular disease or lead to an early death, according to a study published in the Journal of the American College of Cardiology.

The research review was published in advance of the release of the new USDA Dietary Guidelines later this year, with the intent of making the case to remove the long-standing ceiling on saturated fat intake.

In 2016, after decades of urging Americans to watch their overall fat intake, the USDA officially removed the upper limit from total daily fat. They kept the cap on saturated fats, however, which recommends keeping saturated fats to no more than 10 percent of daily calories, a guideline that has been in place since 1980.

Now after poring through decades of data on saturated fats and health, a group of scientists says it’s time to lift that limit as well.

Summing up meta-analyses and other studies that include hundreds of thousands of people, the study concludes that reducing foods rich in saturated fatty acids doesn’t reduce risk of cardiovascular disease or death from any cause. On the contrary, some research suggested that there was a lower risk of stroke with a higher consumption of saturated fat. It’s true that eating saturated fatty acids like stearic, palmitic, myristic, and lauric acids—which are found in full-fat dairy, meat, eggs, and other fat-rich foods—increases levels of undesirable low-density lipoprotein (LDL)-cholesterol, but in most people, it doesn’t increase this kind of “bad” cholesterol.

Specifically, saturated fat doesn’t generally increase levels of small, dense LDL cholesterol, which raises your risk for heart disease, but rather increases levels of larger, more bouyant LDL particles, which are not related to increased risk.

By wholesale limiting “saturated fats,” you could miss out on foods that provide high-quality nutrition, and possibly substitute it with a far less healthy option, like processed or starchy carbs, which actually do raise your risk for heart disease, according to the researchers. So it’s better to focus on the overall quality of foods in your diet rather than any specific macronutrient.

“Among foods that are usually called ‘saturated fats,’ some are healthy and some are not, so that the amount of saturated fatty acids (SFA) in a food is not a good predictor as to whether it is healthy,” study researcher Tom Brenna, Ph.D., professor of Human Nutrition and Pediatrics at the University of Texas at Austin, told Bicycling.

“That is, considering only the saturated fat content would lead to avoidance of very healthy foods—whole dairy, fermented foods [yogurt, cheeses], and others. As a general rule, whole traditional foods are generally healthier than highly processed foods,” Brenna said.

Dairy, for instance, is a major source of saturated fatty acids, but food-based meta analyses have found that eating more cheese and yogurt is linked to lower cardiovascular disease risk, researchers said.

Likewise, eggs are rich in saturated fatty acids, but they’re also nutrient dense and provide antioxidants like lutein and zeaxanthin that are hard to get in other foods. Studies have gone back and forth over the years regarding the relationship between egg consumption and heart disease, but a number of meta-analyses have found that higher egg consumption is not associated with risk of CHD and may be associated with lower risk of stroke, say the researchers.

Dark chocolate contains stearic acid, a fatty acid that neither raises nor lowers CVD risk. But if you skip the cocoa-based confection because of its saturated fat content, you also miss out on flavonols, which reduce inflammation, are good for your vascular health, and can even raise your VO2 max (how efficiently you use oxygen).

Finally, although processed meat, like sausage and hot dogs, has been linked to an increased risk of heart disease, unprocessed meat has not, which indicates that the saturated fat in meat itself is not the culprit behind the elevated risk, the researchers said.

The bottom line: Eating real food is better for your heart and your overall health than stressing over any particular macronutrient.

It’s worth noting that six of the 11 researchers on the paper have received funding from dairy, beef, and other food associations and foundations. Many of the 130 papers cited have no competing interests or claim no role in study design, data collection, data analysis, and results interpretation.

Selene Yeager “The Fit Chick” Selene Yeager is a top-selling professional health and fitness writer who lives what she writes as a NASM certified personal trainer, USA Cycling certified coach, Pn1 certified nutrition coach, pro licensed off road racer, and All-American Ironman triathlete.

3 Tips to Help You Be a Fitter, Healthier Athlete at 50+

Nick Beer Feb 8, 2019

As we get older, the training focus needs to shift toward preservation and protection.

As we roll into our 50s, the health benefits of maintaining an active lifestyle become much more apparent. This is partly due to the decline in our physiological systems that are affected by the aging process. The importance of including strength training should no longer be considered a recommendation, but rather a necessity. The training focus needs to shift toward preservation and protection, instead of pushing and powering through. Take a look at why, and what we can do about it:

Decreased Ability to Preserve Muscle Mass

We are in a constant state of muscular breakdown, which can greatly increase our chances of injury. Incorporating exercises, like the ones below, are a huge benefit to maintaining muscle mass and bone density:
• Deadlifts
• Squats with weights
• Press ups
• Pull ups

A Loss of Balance and Control

It is not uncommon for some of our motor skills—such as balance— to slowly decrease as we age. This can impact our technique and lead to injury. Exercises that may help manage coordination and retain overall neural awareness include:
• Single-leg standing hold
• Single leg on an uneven surface (BOSU)
• Single-leg hops
• Landing drills

Reduction in Muscular Strength and Endurance

Our bodies naturally slow down as part of the aging process. Training becomes harder, and recovery takes longer. Below are core and injury prevention exercises
that can be added to any strength program:
• Side leg raise
• Side + full plank
• Standing high knee raise
• Clamshell raise

Nick Beer is a former elite triathlete from Great Britain. Having competed around the world in some of the top races, he’s now a strength and conditioning coach, specializing in sports-injury rehabilitation.