Why weightlifters need cardio

Improve your health, power, strength, size and physique with cardio
Ian Locke
Ian Locke
Nov 23, 2020

Most people have firm views on health and fitness and what the best way to achieve their goals is. Often it involves doing lots of one type of exercise – that’s why runners run longer and longer distances and weightlifters rarely move fast.

We’re here to tell you why we believe weightlifters should do cardio.

What is cardio?

Cardiovascular exercise (aka cardio) is any exercise which raises your heart rate for a sustained period, unlike weightlifting which raises it for short bursts. Depending on your level of cardiovascular fitness, it could include walking, running, swimming, cycling, rowing, climbing, dancing, housework, etc.

Weightlifters and bodybuilders need cardio too
Weightlifters should do cardio exercise to improve heart function

Low intensity cardio raises your heart rate a little bit and you can carry on for hours without getting tired; very high intensity exercise will make you feel like your lungs are screaming and can only be sustained for a few seconds.

It’s all cardio, but as that word has negative associations for some, we’re going to call it conditioning and explain how weightlifters can use conditioning to improve their health, fitness and reach their goals faster.

Reason #1: Your heart and lungs will thank you

If our heart and lungs are not fit for purpose, then quite frankly things aren’t looking good, are they? Our lungs need to pass enough oxygen into our blood, and our heart needs to be able to pump that blood around our bodies in sufficient volume and at the right speed, for our bodies to do what we ask of them.

Weightlifters who are out of condition and only focus on lifting weights run the risk of increasing the thickness and strength of the heart, without building space for sufficient blood to pool between heartbeats. This is called left ventricle hypertrophy and is seen in people who lift heavy weights or those who are chronically stressed.

It means that when the body demands more blood flow (e.g. exercise), the heart needs to pump harder and faster than it would ordinarily have to in order to circulate the same volume of blood.

Adding conditioning to your training programme can increase the volume of blood in the left ventricle, reducing the number of heartbeats needed to meet the demand for oxygenated blood around the body.

And yes, the opposite issue can also be a problem; those who only do conditioning can have a left ventricle which is too large for the power of the heart. The good news is that it’s easy to get an indication of whether you have an issue or not by measuring your blood pressure and resting heart rate.

Blood pressure (BP)

If you don’t have one, get yourself a monitor (available from £20 upwards) and measure BP at least weekly. Here’s why knowing your BP is important:

  • A study in 2002 reported that 68% of all-cause mortality attributed to BP in the US happens between 120 and 140 mmHg.
  • For every 20/10 mmHg increase in BP, cardiovascular risk was seen to double.
  • Reassuringly, a reduction of 5 mmHg correlated with a 7% reduction in cardiovascular risk.

The NHS classes BP of 120/80 mmHg as healthy and only starts to get concerned above 140/90 mmHg. Thrive and the US now use 115/75 mmHg as an indication of good BP.

If your BP is higher than 115/75 mmHg, consider adding conditioning to your programme. And speak to a doctor if you have any concerns.

Resting heart rate (RHR)

A low RHR is a sign that your heart and lungs are healthy and can keep ticking over with minimal effort – result! The NHS suggests 60 beats per minute (bpm) is healthy but Thrive prefers it to be below 55bpm:

  • A study found all-cause mortality increased linearly as RHR increased above 45bpm.
  • By the time RHR hit 90bpm, a significantly increased risk of cardiovascular mortality was observed.

Reducing your RHR will reduce your health risks, but weightlifting increases it. That’s why it’s important to keep an eye on it and as most smart watches and phones with cameras can measure your heart rate, there really is no excuse.  Measure yours first thing in the morning each week.

Reason #2: Weightlifter will lift more weight

How fast does your breathing rate recover after a heavy set? If you find you’re still panting by the time your rest period is up, or it’s as much as you can do to walk up to the squat rack, then you should work on your energy production with conditioning.

The energy-producing magic happens in our mitochondria, which sit in our cells and trigger the little sparks of energy that drive everything we do. They are sensitive things and are negatively impacted by stress, toxins and free radicals. As well as exercise, their productivity is guided by genetics, nutritional deficiencies, and thyroid hormones.

We can encourage our bodies to make more mitochondria and get them to work harder through conditioning.  In fact, it’s been shown that aerobic training can improve mitochondrial health by 50% in only a few weeks.

By having more, healthier, harder working mitochondria, not only will you have more energy generally, but you’ll be leaner as you’ll burn through more free fatty acids to power the mitochondria.

Reason #3: You’ll get leaner

Intensive exercise, including weightlifting, stimulates a release of adrenaline which causes our bodies to release fuel into our blood in order to keep up the intensity for as long as possible.

When we stop training intensively, the residual fuel will be re-stored in our body for another time. Here’s the clever bit: if we follow intensive training with less intensive conditioning, we will use that fuel for movement and become leaner as a result.

Adding 20 minutes of conditioning to the end of your weightlifting sessions should be sufficient.

Reason #4: Improved performance starts with recovery

Exercise is necessarily stressful on our bodies. It’s through our stress response that our body adapts, grows, gets stronger, faster, etc. Stress for short periods is generally fine – it’s long-term stress which causes no end of issues.

But that depends on how well your body recovers. If there’s insufficient time for recovery, or some other factor impacting it, then your progress is going to be limited.

Conditioning is known to reduce the stress load on our bodies and therefore we recover faster. We know this through measuring heart rate variability (HRV). HRV is a measure of the variability in our heartbeats – the less stressed our body is, the greater the variability of our heartbeats. You can measure it through mobile apps such as Elite HRV, but the concept is what’s important:

  • Weight training creates stress which lowers HRV.
  • Conditioning floods our body with nutrients and oxygen, which helps reduce stress and increases HRV.

You can have too much of a good thing.  Very high HRV (for example, as seen in elite marathon runners) can make it hard to gain muscle and maintain muscle tone.

If your phone allows, monitor your HRV regularly to find your base level. If it takes a dive, you need to stay out of the gym for a few days and do some conditioning. If it keeps on rising, you can train more intensively.

What and how much conditioning should you be doing?

The good news is that replacing one of your weight training sessions every 7-10 days with conditioning will be enough to maintain a good level of conditioning. Without any training, conditioning levels generally only regress 1% per week; compare that to losing 25-30% of strength, power and speed within 12 weeks of not training.

If your conditioning needs a boost (perhaps you’re not able to recover well, have high BP, high RHR or low HRV), then you’ll need to schedule a block of training which focusses on conditioning alone. 5-8 weeks, once or twice a year should be enough.

That may start ringing alarm bells as you think of your muscles shrinking, but you can mitigate this by choosing your conditioning programme carefully. And you’ll see better results from weightlifting when you get back to heavy lifting.

There are plenty of options for conditioning, both in format and activity. Suggestions include:

Low impact steady state (LISS) exercise

Pick an exercise you can do for long periods at low intensity (e.g. run, swim, row). Your heart rate should be raised, but not to the point you struggle to breathe or which causes burning in your muscles.

Interval training

Work at a higher intensity than LISS for short periods, rest and repeat.

Every minute on the minute (EMOM)

Pick 2-5 exercises you can do 10-20 repetitions of (e.g. squats, press ups, bench jumps). Look at a clock and every time a new minute starts, complete the repetitions of one exercise as fast or slow as you like. However, your rest is limited to the time it takes for the next minute to start. Then move on to the next exercise and repeat until your session is done.

Tempo weights

If you really can’t face exercising without weights, then try this:

Final thoughts

There is no definitive set of rules to work this stuff out. We all respond differently to exercise and we’re all starting from different places. The important thing is to be aware of how your body is functioning, trying different things and working out a balance which means you can focus on your primary goal in the medium term, even if you have to divert efforts every now and then.

Oh, and if you don’t have a blood pressure monitor, go buy one and use it regularly. Then call us to find out what your reading means or check out our unified training programmes.

Are you ready to thrive?

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