Weight training can improve heart disease risk factors in just 30 minutes a week, according to a new statement by the American Heart Association.
The recent scientific statement suggests that resistance training is at least as safe as aerobic exercise for those with heart disease and other health conditions.
It also suggests that, for most people, it can provide similar or additive benefits in lowering risk factors for cardiovascular disease.
Abbi Lane, the statement’s senior author and assistant professor at the University of Michigan School of Kinesiology, discusses what this means and how to start resistance training:
What specific information does the 2023 AHA statement add to the 2007 statement? What does it mean for people with cardiovascular disease?
The 2023 statement was necessary as the evidence linking resistance training to lower heart disease risk had expanded so much. We added information about resistance training and novel heart disease risk factors, such as sleep, mood, and the flexibility of the blood vessels. We added a guide for promoting resistance training so health care providers can help their patients start and stick to a resistance training routine.
What are some of the key findings?
In 2007, and probably even today, not everyone was aware that resistance training is good for heart health. The abundance of research suggests that resistance training is at least as safe as aerobic exercise, such as walking and biking, for people with and without heart disease. Resistance training is linked to about 15% lower risk of mortality and 17% lower risk of heart disease compared to adults who report no resistance training.
Resistance training improves not only traditional heart disease risk factors, such as lipids, glucose, and blood pressure, but also nontraditional heart disease risk factors, such as sleep, mood, quality of life, and the way blood vessels function. For example, resistance training is associated with a 0.34% decline in average blood sugar levels for the past two or three months in older people with diabetes. In healthy people over 40, resistance training can help reduce blood pressure by -4/-2 units. There are greater reductions in people with higher blood pressure.
There’s medium-sized improvement in self-rated mental and physical health and a 2%-3% increase in blood vessel reactivity in people with and without heart and metabolic diseases. Improving reactivity is important because it means you’re able to supply blood and nutrients to areas of the body that need it. Low vessel reactivity is an early event in the development of heart disease. Improving reactivity is important because it means you’re able to supply blood and nutrients to the area.
The AHA statement provides a prescription for weight training and a training program progression. Can you paraphrase the recommendations here?
People should aim to complete resistance training two days a week for maximum benefits. You should perform 1-3 sets of 8-10 different exercises that include all your muscle groups. Most people should perform 8-12 repetitions of each exercise.
It’s OK to start with light weights, and you should pick weights that make you feel like your muscle is tired but not failing by the last rep. A couple sets of dumbbells or some resistance tubing or bands will suffice. You can use what you have—canned goods or milk jugs filled with water are great dumbbells. Body weight can work just as well as fancy equipment, so you don’t need to be a gym member or to buy a lot of equipment.
It’s time to lift heavier weights for an exercise when you can achieve two or more reps in a couple of workouts before you reach muscular fatigue. You can also experiment with shorter rest intervals to increase intensity after you’ve been resistance training for at least a couple of months. Try to have at least 1-2 days of rest between resistance training workouts to allow your nerve and muscle adaptations to occur.
The statement looked at resistance training vs. aerobic training, vs. combined training (weight training and cardio combined) and heart disease risk factors. What did you find?
I think the overall message is that combination training is optimal for reducing heart disease risk. Aerobic and resistance training offer benefits that can be additive or synergistic, so ideally a person will complete both types of exercise. But any type of exercise is better than no exercise, so pick the one you like best if you can’t commit to both at any given time.
Aerobic and resistance training are comparable for improving blood pressure and lipids. Combination training seems to have the biggest benefit for improving blood glucose, followed by aerobic training.
Resistance training results in greater increases in lean body mass; aerobic training results in greater reductions in fat mass; combination training has the biggest benefit for improving body composition overall.
Body weight can be expected to decrease by roughly 4.4 pounds with combination training, about 2.8 pounds with aerobic training, with no significant weight loss with resistance training. However, resistance training can help maintain weight when performed with aerobic training, likely because of an increase in metabolic rate, fat oxidation or lean mass.
Who should not do resistance training?
The list of people for whom resistance training is not recommended is the same as for aerobic training. Broadly, it’s people with uncontrolled high blood pressure (systemic or pulmonary), unstable heart disease and arrhythmias, aortic dissection and Marfan syndrome. People with diabetes, controlled high blood pressure, pacemakers or defibrillators, past stroke, clinically low exercise capacity or musculoskeletal issues and pregnant people should clear exercise with their doctor before beginning a program.
Was there anything in these findings that surprised you?
I was surprised about how powerful resistance training can be, especially in conjunction with aerobic exercise. I am a lifelong fan of resistance training, but summarizing the evidence suggesting resistance training favorably influences multiple heart disease risk factors in different types of people was eye-opening. I am so encouraged by the evidence because I think that resistance training is free from barriers that prevent so many people from doing aerobic exercise.
There are lots of fitness influencers on social media. How do you know if someone is any good?
My opinion is they should have some education (hopefully, an associate’s or bachelor’s degree in a related field) and certification from a recognized organization. The American College of Sports Medicine, the National Strength and Conditioning Association and National Academy of Sports Medicine are good certifications. It’s not enough just to be a person who exercises every day or has a nice physique. Nutrition advice should come from a qualified professional registered dietician.
Source: University of Michigan
