Are you into strength training, cardio, HIIT or yoga? While all movement is good movement, each has it’s own unique benefits for your body’s fat, lean mass and bone density.

A kind of blueprint for your health, body composition is a breakdown of the core components of your body: fat, muscles, bones, connective tissue, and water. In the health and fitness world, body composition is often used to reveal your body’s proportions of fat mass (essential and non-essential or stored) and fat-free or lean mass (muscles, bones, tissues, and organs—everything in your body that isn’t fat).

Compared to traditional measures like body mass index (BMI), body composition delivers a more accurate blueprint of your overall health. Tracking your body composition over time can reveal changes in your fat mass, lean mass, and body fat percentage in a way that the scale can’t.

Your body composition is influenced by a number of factors, including several determinants beyond your control—like genetics, age, ethnicity, and hormones. However, there are two powerful ways you can build a healthy body composition: nutrition and exercise.

Second only to nutritional changes, physical activity and exercise are the most critical components for changing your body composition. Depending on the type of exercise, you can build muscle, burn fat, or both. In this article, we’ll review the origins of four of the most common types of exercises and compare and contrast their effects on your body composition.

Strength training

Humans have been practicing strength training for centuries. Resistance exercises were performed by the ancient Egyptians, whose tombs reveal people lifting, swinging, and throwing bags of sand and stone. Though strength training exercises were practiced by ancient Egyptian, Chinese, and Indian civilizations, they are often credited to the ancient Greeks, who established the weightlifting competitions that predated the modern Olympics. Over the years, strength training has evolved to include dumbbells (1700s), kettlebells (1800s), and resistance machines (1970s).

What is strength training?

Also known as resistance or weight training, strength training is a type of exercise that causes a specific muscle or muscle group to contract against external resistance or force as a means to improve muscular strength. External resistance or force can come in many different forms, including free weights, weight machines, resistance bands, and your own body weight.

The benefits of strength training

Until recently, we primarily relied on strength training to increase muscle size and strength. However, a growing body of evidence suggests strength training has additional benefits for fat loss, bone growth, and overall health.

The benefits of strength training on body composition include:

Builds lean muscle mass. Strength training increases the size of major muscle groups, thereby building lean muscle mass. Building lean muscle mass improves athletic performance as well as your ability to perform daily activities. Research has found that ten weeks of strength training can increase lean muscle mass by around three pounds.

Strength training causes micro-tears to muscle fibers, after which the body repairs by synthesizing new muscle mass during periods of rest. Each time this healing process occurs, your muscles adapt by growing bigger and stronger.

Counteracts age-related muscle loss. At around age 30, you typically begin to lose around three to five percent of your lean muscle mass per decade. The loss of lean muscle mass translates to a decrease in strength and mobility, increasing your risk of falls and injuries. Strength training helps counteract age-related muscle loss by helping preserve or build lean muscle mass.
Strengthens bones. Much like muscle loss, age-related changes and inactivity can result in a reduction of bone mass at a rate of one percent per year after the age of 40. Bones that are brittle are more vulnerable to fractures and breaks. Fortunately, strength training can help prevent bone loss, and some studies even suggest that it can build stronger, denser bones. Strength training places stress on the bones, triggering bone-building cells into action. Strength training is particularly effective for strengthening hip, spine, and wrist bones—the bones most likely to experience fractures.
Keeps burning fat after your workout. Aerobic exercises like running and cycling have long been heralded as one of the most effective ways to torch calories and shed extra weight. However, strength training is also a powerful way to cut down fat mass and improve your body composition. When you increase your lean mass, you boost your resting metabolic rate (RMR), or the rate at which your body burns calories during daily life. Research indicates ten weeks of resistance training could increase your RMR by an estimated 7 percent. In addition, strength training workouts boost your excess post-exercise oxygen consumption (EPOC), or the calories your body continues to burn after exercising. Compared to cardio, strength training keeps your metabolism burning hotter for longer after working out. This helps prevent the calorie surplus that causes your body to store excess energy in fat cells and leads to a gain in fat mass.

While strength training has many benefits for your body composition, there are a few potential drawbacks to keep in mind. Working out with improper form, too quickly, or with too much weight can cause injury. In addition, not getting sufficient rest between strength training workouts depletes your glycogen stores and can cause muscle fatigue while denying your muscle fibers sufficient time to heal and grow back stronger.

Aerobic exercise/cardio

Although we have been practicing cardiovascular activity since humans have existed, aerobics wasn’t popularized as a physical fitness concept until the late-20th century. That’s when Kenneth H. Cooper published “Aerobics” (1968) and ”Aerobics Way” (1977), highlighting the importance of regular cardio for a healthy life. Cooper’s research leads to the development of a slew of aerobics workouts, like jazzercize (1970s), Jane Fonda- and Richard Simmons-pioneered video fitness classes, and group exercise classes ranging from hip hop to boxing (1990s on.)

What is aerobic exercise?

Also called steady-state cardio and endurance training, aerobic exercises provide cardiovascular conditioning. Aerobic means “with oxygen,” as your breathing and heart rate increase during aerobic exercise. Unlike anaerobic exercises that involve quick bursts of energy, aerobic exercises are performed for a sustained period. Examples include spin, cycling, and swimming, as well as weight-bearing exercises like jogging, dancing, and jumping rope.

What are the benefits of aerobic exercise?

Cardio training is associated with a slew of benefits, including lowered blood pressure, a decreased risk of heart disease, and improved lung function.

If strength training is favorable for lean muscle mass gain, aerobic exercise is better known for torching fat mass. Studies comparing the two types of training found that resistance training may be most effective at helping you gain more lean mass, while aerobic exercise may be best at reducing fat mass.

Compared to strength training, cardio exercise can be more effective for burning calories and weight loss. You lose weight by burning more calories than you consume.

Because of its fat-torching abilities, aerobic exercise may be best for individuals with a higher percentage of body fat. However, aerobic exercise alone is insufficient to build muscle. And because building muscle requires a calorie surplus, the calorie deficit that comes with aerobic exercise may hinder muscle growth and even cause you to lose muscle mass.

To truly change your body composition for the better, it’s highly advisable to incorporate a combination of both resistance training and aerobic exercise into your workout. Combining those exercises can optimize the growth of lean mass and the reduction of fat mass.

High-intensity interval training (HIIT)

A relatively new fitness concept, high-intensity interval training (HIIT) is credited to 20th-century runners who would intersperse sprints with slower jogging intervals to train for the Olympics. The concept faded somewhat during World War II but re-emerged when professor Izumi Tabata introduced Tabata interval training. Originally used by Japanese speed skaters, the Tabata protocol was based on 20 seconds of high-intensity exercise followed by 10 seconds of rest. HIIT really rose to popularity in the last decade and has been consistently ranked among the top five fitness trends by the American College of Sports Medicine. HIIT principles have served as the foundation of other popular fitness trends like CrossFit and boot camp workouts.

What is HIIT?

High-intensity interval training is repeated, intense bursts of exercise interspersed with periods of recovery. A versatile training technique, HIIT can be applied to both cardio and strength workouts. From sprinting to super-fast swimming, HIIT can be applied to virtually any type of aerobic exercise. Similarly, you can turn a strength training workout into HIIT by shortening your rest periods, adding cardio between sets, cycling between high-intensity and rest periods, and focusing on full-body exercises like pushups and squats.

What are the benefits of HIIT?

The benefits of HIIT include:

Burns fat mass. Research suggests that HIIT may be the most powerful exercise type for reducing fat mass. Not only that, but HIIT has been shown to be particularly effective at reducing visceral fat. Visceral fat is found in the spaces between the organs and has been linked to conditions like cardiovascular disease, breast cancer, and dementia.
Helps maintain muscle. HIIT may not be the most effective exercise for building lean muscle, but it’s unlikely to make you lose it. One study found that HIIT can help you retain muscle, while moderate-intensity aerobic exercise can potentially come with lean mass loss.
Keeps burning fat after your workout. Like strength-training, HIIT gives you the benefit of post-exercise oxygen consumption (EPOC). Research has found that this afterburn effect can last up to 21 hours, meaning you can continue to burn calories for nearly a whole day after your workout.

There are a few disadvantages to keep in mind before trying HIIT. The full-body, complex movements and fast pace of these workouts can make it difficult to maintain good form, which can result in injury and muscle tearing. Because of its intensity, HIIT workouts should only be performed two to three times per week, experts say. And as we’ve noted, HIIT alone is unlikely to help you build lean mass, so it’s best to supplement HIIT with strength training and aerobic workouts.

Yoga

More than 5,000 years old, yoga can be traced back to the Indus-Sarasvati civilization in Northern India. Originally developed by Brahman, or Vedic priests, yoga became common practice in other religions like Hinduism and Buddhism. Yoga has since evolved from a primarily religious practice to a form of workout designed to exercise the body and mind.

What is yoga?

Yoga is a mind and body workout that combines physical postures with breathing techniques and meditation. Over the years, yoga has developed to include many different types, including the latest rendition of laughter yoga.

What are the benefits of yoga?

Depending on the type of yoga, the practice can reduce fat mass and build lean muscle (in addition to a huge array of benefits beyond body recomposition). Let’s go over the effects of different types of yoga on your body composition:

Hatha yoga. This practice focuses on building strength in your core. Because many of the postures require you to use your own body weight as resistance, hatha yoga can help increase lean mass.
Power yoga. Experts claim that power yoga is among the most effective methods for reducing fat and building muscle. Typically more intense than other forms of yoga, power yoga tends to torch more calories.
Bikram or hot yoga. Because hot yoga is performed in 105-degree temperatures, studies suggest that you may be able to burn extra calories thanks to the heat. Other research on Bikram yoga found that supporting weight during the postures may increase bone density.

When it comes to burning calories, yoga may not be as effective as aerobic exercise. Instead of relying on yoga as your only form of exercise, try mixing it up with strength training, cardio, HIIT, or all three!

At the end of the day, any type of exercise comes with incredible benefits for body composition—as well as longevity, injury-prevention, heart health, and mental health. The right exercise for you depends on your current fitness levels and goals. If you are at the beginning of your fitness journey, choosing to take the stairs or going for a walk around your neighborhood is a great place to start!

If you want to track the progress of your fitness voyage over time, it’s a good idea to get a body composition scan when you first begin. This will give you an accurate picture of where you’re starting. As you exercise more and adjust your diet, continue to monitor your body composition by getting a scan every few months. By tracking changes in fat and lean mass, you can determine if your exercise plan is working for you and make changes accordingly.

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The Big Debate: What Type of Exercise Benefits Your Body Composition Most?