Cardio
Is Resistance Training a Good Cardiovascular Workout?
Most fitness experts recommend a combination of aerobic exercise and resistance
training to build muscle strength and boost aerobic capacity and heart health.
Traditionally, cardio exercises such as running, aerobics or cycling were
thought to be best for cardiovascular training and resistance workouts best for
building muscle strength. But these days more people are using circuit
resistance training as a substitute for aerobics. With circuit resistance
training, you move from one strength exercise to the next with little rest
between sets. This elevates the heart rate more than traditional weight
training where there are longer rest periods between exercises. Is circuit
resistance training a good substitute for cardio?
Do You Need to Do Cardio if You Lift
Weights?
Most people prefer strength training over running or cycling on an exercise
bike. They'd rather flex their muscles with weights than spend 30 minutes
working out on a cardio machine. It would be music to their ears to find out
that circuit resistance training conditions their heart as well as traditional
aerobic exercise does. Unfortunately, this may not be the case.
It's logical to think that resistance training boosts aerobic capacity. After
all, your heart rate goes up when you lift weights, and it's elevated even more
when you do circuit style training. There are some differences though.
When you do one of my aerobic videos or run on a treadmill, your heart rate
increases along with stroke volume which is the amount of blood the heart pumps
to the body with each beat. This increase in heart rate and stroke volume
allows muscles that are now more metabolically active to receive greater
amounts of blood and oxygen.
When you lift weights or do some other form of resistance exercise, your heart
rate rises, but stroke volume and oxygen delivery don't increase like they do
with aerobic exercise. The increase in heart rate that occurs with resistance
training is a reflex response that's triggered by muscle contraction. As a
result, you don't get the same increase in oxygen delivery to the muscles with
resistance training. This reduces the cardiovascular training benefits.
Does Circuit Resistance Training Have
Cardiovascular Benefits?
Resistance training with periods of rest between sets has little cardiovascular
training effect. If you minimize the amount of time you rest between sets to 30
seconds or less, you get slightly more benefits but not equivalent to what
you'd get during an aerobics class, running on a treadmill or cycling on a
bike. According to ACE Fitness, circuit resistance training boosts aerobic
capacity around 6%. In contrast, running and cycling can increase aerobic
capacity by as much as 25%.
Does This Mean You Have to Do
Traditional Cardio to Train Your Heart?
Circuit resistance training may not be the best way to increase your aerobic
capacity, but there are ways to make it better. Instead of doing straight
circuit training, do 1-minute cardio segment between each resistance training
exercise. When you finish each strength set, grab a jump rope and skip rope for
a minute, do jumping jacks or run in place before picking up the weights again.
This will give your heart the additional stimulus it needs to adapt without
doing traditional cardio.
Resistance Training Has Other Benefits
Even though resistance training alone doesn't significantly increase aerobic
capacity, it does indirectly benefit the heart. Research shows that
circuit-style resistance training helps to reduce blood pressure over time in
some subjects. Aside from its effects on the heart, it also increases lean body
mass, bone density and improves strength. Almost everyone can benefit from some
form of resistance training.
The Bottom Line?
Resistance training has benefits, but it isn't a good substitute for cardio.
Circuit resistance training can modestly improve aerobic capacity but not as
much as cardiovascular exercises like aerobic classes, running or cycling. To
improve the cardiovascular benefits of resistance training, do short intervals
of cardio between each resistance set. Otherwise, keep strength training, but
make time for cardio too.
References:
ACE Fitness. "Why Is an Elevated Heart Rate Alone Not Always a Valid Indicator
of an Effective Aerobic-Training Stimulus?"
Medscape.com. "Strength Training and Hemodynamic Responses to Exercise: Summary
and Clinical Application"
Medscape.com. "Endurance Exercise and Resistance Training in Cardiovascular
Disease: Benefits of Resistance Training"
