I answered a media query on the benefits of cardiovascular exercise vs weight lifting for Medical Daily. To expand upon it, here’s my take:
Weightlifting builds bone density in the bones of the muscles worked. Squats can help build hip bone density, but not wrist bone density, which would require stress on the wrist from an exercise such as a chest press or forearm exercise.
Weight lifting is effective for increasing glucose sensitivity (blood sugar sensitivity). This means that some people, such as a person who is diabetic, may not need as much insulin as usual or that the person can consume more carbohydrate without negative effects on their body.
Resistance training also builds physical strength, improves muscle coordination, and is a stimulus to the body to increase lean mass. Because of increases in lean mass, weight lifting is effective in improving body composition (lowering fat mass % and increasing lean mass %), which can improve self esteem and body confidence. Being stronger can make daily tasks easier, makes you more athletic, and allows you to push your body more intensely during other exercises.
Cardio in the light to moderate intensity range stimulates the body to increase overall blood volume, thereby increasing the amount of red blood cells if the behavior is maintained for over a month (the time it takes to remake blood cells).
This happens because cardio can stimulate an increase in overall blood plasma volume, the watery component of blood. With more blood volume, the density of the red blood cells in the blood is diluted. The kidneys recognize this and secrete erythropoetin, a hormone that acts on the bone marrow to produce more blood cells to match the new blood volume.
Cardio is helpful for reducing blood pressure acutely. This could be due to relaxation of the blood vessels due to exertion, a loss of fluid and sodium from the body, an increase in nitric oxide production (dilates blood vessels), or a combination of these. Cardio in the light to moderate intensity range also creates adaptations in the peripheral cardiovascular system, such as increasing capillary density and overall efficient circulation.
All cardio will increase the blood circulation by utilizing the muscles of the body to pump blood that is in the veins back to the heart. This is called the muscle pump, and it only works when you are moving. This reduces the work the heart must do to pump fresh blood throughout the body. It also increases the stroke volume of the heart–the amount of blood pumped per heart beat. This can result in lower heart rates due to greater heart efficiency.
Most people can expend the largest amount of energy (calories) with light to moderate cardiovascular exercise when performed to exhaustion compared with weightlifting or intense cardio when performed to exhaustion, which is important when balancing dietary intake of calories.
Light to moderate cardio also does not spike caloric needs for repair as much as weight lifting or intense cardio due to less muscle breakdown, which is helpful for not slowing down the weight loss process (due to increases in lean mass, some people consider the “afterburn”).
To clarify, often people think that more exercise is better for weight loss. This is not true. If your body is broken down, caloric needs increase. If needs are increased while you are not consuming enough for repair, your body won’t lose weight.
Instead, it will stall until it is healed. It’s like, why would it lose weight if you are telling it to gain lean mass. Lean mass gains and weight loss at the same time can be conflicting goals that will take twice as long to achieve either goal. It is important to focus one’s goals.
Think about it. How many people actually lose weight from a marathon? Some people gain weight from it. How does that make sense other than the explanation above? Back to cardio…
Intense cardio can improve VO2max, the maximum amount of oxygen a person can consume and a measure of cardiovascular fitness. Intense cardio improves cardiovascular fitness the best. It burns the most calories per unit of time so is great for maximizing your workout time, if time is limited; however most people fatigue (beginners or athletes) before it would burn an equivalent amount of calories of moderate cardio to exhaustion or even sub-exhaustion.
For me, I know I can burn 600-700 Calories on a treadmill on an incline at a moderate pace in 35-40 min. If I push myself and do intense cardio (mile time speed or sprint intervals), I burn out in 15-20 minutes and have only burned 200-400 Calories. Yes, there is an afterburn, but I think that is overhyped. We don’t talk about the afterburn from weight lifting–we call it soreness or delayed onset muscle soreness (DOMS).
Intense cardio should be performed for the aerobic fitness stimulus and not viewed soley as a caloric energy dump. Successful weight loss clients use exercise to build skills and use larger volumes (sets, reps, time) of exercise to keep it off after the weight loss process is over but not during the process.
Why would you commit to 6 days of exercise for the purpose of weight loss in an unsustainable manner? Are you planning to exercise for 6 days a week for the rest of your life? It’s just asking for an injury. People who request this are often given it by trainers because it can be lucrative, or they don’t know any better themselves.
Listening to a real exercise professional will save you some money and hard work. I do not support these sorts of weight loss endeavors. Diets are there for a reason. It’s all about the dietary caloric deficit. Check out the cool graph on this post, in case you missed it! You’d be surprised how little I exercise to maintain a great physique. Nutrition is very important, and focused, purposeful, goal-oriented exercise also is very important.
Intense cardio also improves central cardiovascular functions (heart, and forced inspiration and expiration muscles) more than moderate cardio, but it is often more physically and psychologically stressful. For this reason, I recommend doing it only when you are rested and recovered (from a leg and cardiovascular workout history standpoint). Cardio will also improve blood sugar sensitivity of muscle at any intensity just as weight lifting will.
If you have any questions about what you are actually doing with a particular form of exercise, I’d love to hear in the comments below. I focus on physiological parameters to improve when designing exercise programs for my clients and me. If you like this post, please comment, subscribe to my newsletter for new articles and updates, and share on social media 🙂 If you want to work with me, check out my services.