You probably know that traditional forms of cardio are not very effective when used as the primary tool for producing fat loss. But, just because steady-state cardio rarely leads to lasting fat loss doesn’t mean that cardiovascular health or a well-functioning aerobic energy system aren’t important for health and performance.
We want to make sure you aren’t selling yourself short by ignoring your aerobic energy system. This article will detail benefits of a high aerobic capacity and tell you how to get it.
How To Develop a High Aerobic Capacity Without Doing Steady-State Cardio
When most people think of aerobic exercise for cardio they think of the steady-state kind in which you run or workout about an exercise machine for about 30 minutes. The cool thing is that you don’t have to kill yourself with cardio to develop excellent cardiovascular health.
In fact, research shows that interval training in which you alternate intense bouts of activity with rest periods is highly effective for improving aerobic capacity and experiencing the cardiovascular health benefits that go with it.
For example, a meta-analysis of the effect of sprint interval training found that it improves aerobic capacity in previously sedentary people. It is equally as effective as continuous endurance training, and it allows trainees to perform a reduced volume of activity. A second analysis found that interval training improved VO2 Max, or the body’s ability to use oxygen, by between 4.2 and 13.4 percent in 13 studies.
You might wonder why a high aerobic capacity even matters. It has major cardiovascular benefits as you’ll see below, and it’s necessary if you have any interest in being able to sustain activity for an extended period.
Plus, there are certain metabolic adaptations associated with aerobic capacity such as an increased ability to burn fat during exercise that are highly favorable for maintaining a lean body composition.
The Benefits of A Well Functioning Cardiovascular System
#1: Improved Cardiovascular Efficiency
One of the greatest reasons to maintain a high level of aerobic fitness is that it makes the heart more efficient. You probably know endurance trained athletes have significantly lower heart rates than the rest of us, so the heart is pumping blood less often when you’re fit. But more blood is being ejected from the heart with every beat. How does this happen?
Endurance athletes develop larger hearts than sedentary people because the left ventricle cavity that moves oxygenated blood to the heart increases in size. More oxygenated blood reaches your brain and muscles, but with less of an effort.
What most people don’t know is that strength and power athletes also have larger hearts (in fact, elite shot putters and wrestlers have some the largest heart volumes recorded), but their heart walls get thicker in response to brief periods of high blood pressure due to straining as they try to produce high forces.
Neither of these adaptations is dangerous, but the changes you get from endurance-style training are more useful because it saves your heart effort. This is great for longevity, and it improves recovery during strength training.
Lifting weights is anaerobic (not using oxygen), which could make you think that the efficient delivery of oxygenated blood to the muscles isn’t all that relevant. But, once you put the weight down and recover between sets, the aerobic system takes over, delivering oxygen to the muscles and brain and removing byproducts that limit performance.
#2: Less Stress & Better Sleep
It may surprise you that peak cardiovascular fitness will reduce stress and improve sleep since just the idea of long, slow cardio session probably stresses you out. In addition, most people know that high-performing endurance athletes have elevated cortisol.
But training the aerobic energy system produces adaptations in the central nervous system that reduce stress response at rest and during exercise. At rest, we increase activity of the calming parasympathetic nervous system, which is often known as the “rest and digest” system.
A more dominant parasympathetic system contributes to a lower heart rate, and it helps you relax and deal effectively with stress because your sympathetic nervous system—the one involved in “flight or fight”—isn’t constantly jazzed up from all the annoying things we have to deal with during the day.
This translates into reduced anxiety, less neuroticism, a better mood, and best of all better sleep and recovery from intense training.
#3: Improved Recovery & Less Muscle Soreness
Here’s how a high aerobic capacity can aid recovery: First, we know that a high-training frequency can decrease muscle soreness and improve gains because the muscles get conditioned to the hard training, which is only possible if you’re sleeping well and recovering well between sessions.
Second, studies show that one of the best ways to reduce DOMS muscle soreness is to perform exercise that taps into the aerobic system, getting more blood, oxygen and nutrients to the muscles to speed recuperation.
This can be done with aerobic-style conditioning or by doing light-load concentric lifting for high reps. For example, a typical muscular endurance workout in which you use weights below 50 percent of the 1 RM and do 25 or more reps per set can reduce DOMS.
#4: Greater Ability to Burn Fat for Energy
Normally, burning body fat is a slow process and the body is “reluctant” to do it if glucose is available. But aerobic conditioning leads to a variety of adaptations that increase fat burning including the following:
1) Increased blood flow to muscle so that it can use stored intramuscular fat during exercise,
2) More fat burning enzymes, and
3) Greater sensitivity to catecholamine hormones that increase fat metabolism.
A greater metabolic flexibility is extremely beneficial for getting lean, but it also has favorable implications for health (improved insulin sensitivity and less diabetes risk), inflammatory status (oxidative stress will be reduced), and convenience (you don’t have to constantly replenish carbohydrate energy stores.
#5: Reduced Blood Pressure
Exercise is the most effective lifestyle habit available to reduce blood pressure. Both regular strength training and aerobic-style training can reduce blood pressure in the long-term.
However, weight training, especially heavy training with straining exercises like a heavy squat or deadlift produce a large increase in peripheral resistance. Blood pressure goes pretty sky high during a lifting set and people who already have high blood pressure need to avoid this.
They are going to get best results by favoring exercise that trains muscular endurance. The blood vessels dilate quickly to get working muscles the oxygen necessary, and the alternate muscle contraction and relaxation of more repetitive exercise result in large beneficial adaptations in systolic blood pressure.
For example, you could try what Brazilian researchers did in a study with older hypertensive women with an average age of 61. They did a weight training workout with 90-second, walking rest periods, which led to a significantly lower acute blood pressure response. The aerobic nature of the rest periods increased blood flow and activated the mechanisms of shear stress, resulting in an increase in the production of nitric oxide that dilates the blood vessels.
Final Words: How To Achieve A High Aerobic Capacity Without The Negatives of Aerobic Training
By now you’re familiar with the valuable benefits of a high aerobic capacity, but what about those negatives you’ve heard about? How does aerobic training go wrong and what can you do about it?
A glance at hormone levels in endurance trainees shows that compared to sedentary people, they have better insulin health, glucose tolerance, and a greater sensitivity to the stimulating catecholamine hormones. But there are some serious hormonal downsides to regularly training the aerobic system, especially with high volume or intensity.
Endurance athletes experience reduced androgen hormones and high cortisol levels. For example, male endurance athletes generally maintain resting testosterone levels between 60 and 85 percent of values for sedentary men. Trained females have altered follicle stimulating and luteinizing hormones, which often leads to altered menstrual function and health complications.
Resistance-trained and power athletes tend to experience the opposite hormone profiles: Higher androgens and better cortisol balance. These differences highlight how intense, frequent aerobic training can be detrimental to health. Here are a few key take away points for anyone who wants to achieve the best of all worlds:
* You don’t need to choose between achieving a high aerobic capacity and strength. Instead, you can train both throughout the year.
* You can significantly improve aerobic capacity and achieve all of the cardiovascular benefits described above from only a few months of training that challenges the aerobic system. Depending on initial fitness, duration, and intensity, just 4 to 8 weeks of training can get your aerobic energy system in gear without compromising power and strength.
* You don’t have to do continuous boring cardio to develop these benefits unless you enjoy it. You can do aerobic intervals: Try doing four 3-minute intervals at 85 percent of maximal (just below “Hard” on an RPE scale) interspersed with 3 minutes of rest. Finish with two 2-minute intervals at the same intensity with 2 minutes rest.
Or try this: Do ten 1-minute intervals at 90 percent of maximal (“Hard” on an RPE scale) with 1-minute active rest intervals (jog or cycle). Work up to completing 15 reps.
* These recommendations don’t necessarily apply to competitive strength or power athletes. Aerobic training that is performed more than three times a week for longer than 20 minutes can compromise strength and muscle mass adaptations.
Interval-style aerobic training is an alternative to steady state models for such athletes who need or want the beneficial energy system adaptations of a high aerobic capacity.