When it comes to exercise, everyone has certain strengths and weaknesses in different areas. Often, I have been asked, “Why is lifting weights so much easier for me to do than cardio?”
Or, the reverse, “Why is cardio so much easier for me than lifting?”
Both resistance training and cardio have many health benefits and will help you in your journey to lose weight or improve your health. In fact, combining the two will give you the most well-rounded results.
It is important to note that these two types of training use different energy systems; we have a tendency to repeat doing the things we are naturally better at. So, if you enjoy lifting weights more than doing cardio, and feel strong in doing it, you are utilizing the anaerobic system. If you are more of a runner or cyclist who loves cardio, you are using your aerobic system for the majority of your training.
So, what is the difference?
Aerobic exercise, what most people categorize as “cardio,” is known as physical activity that increases the heart rate and promotes increased use of oxygen in order to improve the body’s overall condition, generally performed continuously or in a steady state. This type of training builds your endurance and improves your cardiovascular system and respiratory function and is known as being the “oxygen” system. With this type of exercise, energy in the form of ATP is used to carry oxygen to the skeletal muscles in order to perform. Aerobic conditioning, therefore, is measured by finding someone’s VO2 max, or peak oxygen consumption, most commonly measured using a treadmill protocol accompanied by a consumption analyzer or using mathematical formulas.
Anaerobic exercise is “without the use of oxygen,” and is short-lasting, high-intensity exercise where the demand of oxygen exceeds the supply that is available. This requires the body to use energy that is stored in the muscles as glucose, causing micro tears and the buildup of lactic acid. The micro tears that happen while lifting weights repair themselves and result in the growth of muscle mass, as well as contributing to that soreness you feel one or two days after completing a tough resistance training workout. The build-up of lactic acid that occurs during anaerobic training is what leads to muscle fatigue while performing your training routine, which your body acclimates to as you continue to improve your training.
The body being able to handle a higher capacity of lactic acid leads you to be able to perform more reps, or heavier weight without that fatigue stopping you.
