Cardio and Heart Health

At this very moment, around 620 million people are living with heart and circulatory diseases, and by the end of the year, another 60 million more will have been diagnosed. In recent years, these deadly diseases have accounted for 20 million deaths annually, which is close to a third of all deaths globally.

While the risks are huge, so too is the opportunity to mitigate them.

Eating a nutritious diet, cutting back on salty or high-fat foods, maintaining a healthy weight, not smoking, and cutting stress … these are all well-regarded ways to protect your heart health. Getting a daily dose of physical activity is also key, but what constitutes the optimal exercise prescription has been the subject of much debate.

What type of physical activity is best?

When it comes to choosing the best type of exercise for heart health, cardio workouts have long been considered the most obvious option. Even the name cardio highlights the undeniable link (it’s short for cardiovascular, which means ‘relating to or involving the heart and blood vessels’). Cardio workouts typically lower blood pressure and help the heart and lungs function more efficiently, and there is lots of evidence linking cardio-based activities like running, cycling and aerobic exercise to a healthy heart.

However, in recent years some scientists have suggested that strength training could be a superior form of training. A team of US researchers spent 11 years studying the exercise habits and medical history of thousands of men and women. They found that even a small amount of resistance training was linked to a healthier heart, while the risk of heart attack or stroke was roughly 50 percent lower for those who lifted weights compared to those who didn’t. Interestingly, the lower-risk people lifted weights twice a week for an hour or so in total. This study also suggested that the strength trainers benefited from reduced risk even if they didn’t engage in frequent aerobic exercise.

But now fresh findings have thrown that call on its head.

“People are increasingly understanding the importance of strength training …. But keeping up cardio is important too,” Bryce Hastings, Les Mills Head of Research.

The change in thinking comes after researchers at Iowa State University led one of the longest and largest supervised exercise trials. They worked with 406 individuals over 12 months, randomly assigning people to either: no exercise, cardio only, resistance training only, or a mix of cardio and resistance. The three exercise groups then worked out under supervision for one hour, thrice a week, for one year. The workouts were based on their individual fitness levels, health conditions and progression, with aerobic exercise adjusted to match prescribed intensity levels. Along the way, researchers measured each participant’s cardiovascular disease risk factors – systolic blood pressure, low-density lipoprotein cholesterol, fasting glucose and body fat percentage.

After a year of training, all of the exercisers saw significant decreases in body fat compared to the control group. This is important as, according to the study authors, every 1% body fat reduction is associated with a 3% lower risk of hypertension, a 4% lower risk of hypercholesterolemia, and an 8% lower risk of metabolic syndrome – all of which are cardiovascular disease risk factors.

The scientists identified how dividing exercise time between cardio and strength training was beneficial, noting that splitting the recommended amount of physical activity between aerobic and resistance exercise may reduce cardiovascular disease risks to the same degree as cardio-only training. Yet, doing nothing but strength training for the same amount of time is unlikely to provide the same heart health benefits.

“People are increasingly understanding the importance of strength training, and it’s quickly becoming the most popular way to train. This research provides a timely reminder that keeping up cardio is important too,” says Bryce Hastings, Les Mills Head of Research. Hastings adds that one of the strengths of this study was that each training group exercised for the same duration each week (something that isn’t always consistent for this type of research).

The study showed that even short durations of less than an hour per week can provide substantial cardiovascular benefits. However, Hastings adds that circuit workouts (which alternate both cardio and resistance in shorter bursts) are less understood in terms of their effects on cardiovascular disease.

In a nutshell:

A 50:50 mix of cardio and strength workouts can be a winning formula for heart health.

TOP TIP: It’s recommended to do the strength component of your workout first so that your stabilizing muscles aren’t fatigued.

Try a 50:50 Hybrid workout at home using LES MILLS+

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