I didn't always lift weights. I followed, for a long time, the popular opinion that any free time I had at the gym should be spent doing cardio in order to get fitter and burn fat. If I did any weight bearing exercises they were usually with very light weights and high repetitions.
A couple of years ago I wanted to add variety into my exercise regime and I thought I'd give weight training a go. I started with a personal trainer to help me with form and technique and since then I've never looked back. In 6 months of weight training my body changed far more than years and years of doing only cardio. I increased my lean muscle mass, lost body fat and most importantly I felt great.
Many women feel that lifting heavy weights will make them bulky and too muscular. Let me tell you now that is definitely not the case! Building big muscles takes a huge amount of effort including lifting heavy weights many times a week, along with a strict diet of high protein intake and supplements. Remember too that you need a fair bit of testosterone hormone to look bulky. Women have ten times less testosterone than men therefore they are physiologically unable to look like a bodybuilder (not that there's anything wrong with that!) without a LOT of hard work.
So, for optimal fat loss and lean muscle gains it's important to include strength training into your routine and even reduce the amount of cardio you do. Let's look at this in a bit more detail.
WEIGHT TRAINING HAS A MORE POSITIVE EFFECT ON METABOLISM THAN CARDIO
A key factor when it comes to weight loss is a healthy metabolism.
Muscle is a very "metabolically active" tissue which means the more you have the more efficient your metabolism will be. One of the key things to note here is that when you are doing a cardio-based workout you burn energy only while you are doing it. With weight training you continue to burn energy even after you've stopped working out. Why is this? It all comes down to your BMR or Basal Metabolic Rate - the amount of calories your body needs for basic functioning. When you weight train you essentially 'damage' or tear the muscle fibres in your body. Repairing these fibres involve a lot of energy from the body which means burning more calories for longer periods of time - the average muscle repair process takes 1-2 days so that's energy being burned up to 2 days after you finish a strength training session! You don't get that same result from cardio alone. In fact, excessive cardio can actually promote muscle loss. This can lead to a lower resting metabolic rate and a reduction in important hormone production.
A study by the Journal of American College of Nutrition showed that test groups who engaged in aerobic exercise lost body weight but also lean muscle mass; the same group had a reduction in their resting metabolic rate at the end of the study. The test group who performed resistance training (strength training) 3 days a week increased lean muscle mass and resting metabolic rate.
So how does this equate to fat loss? After a weight training workout when your muscles are in recovery mode your body will be forced to tap into stored body fat for the recovery energy. So it's a win-win!
HOW STEADY STATE CARDIO CAN ACTUALLY PREVENT FAT LOSS
Steady state cardio, ie, aerobic based exercise, running, cycling, dancing, and so on is a great way to burn calories and is beneficial for the heart. However, aerobic exercise is a catabolic activity (a biochemical reaction that breaks down molecules) therefore it can actually burn or breakdown the muscle. Weight lifting on the other hand, is an anabolic activity which builds up muscle. When we start to lose muscle tissue (ie, the muscle is being used for energy) the body enters a form of "survival mode" and starts to store body fat as a result.
As study from the Journal of Applied Physiology found that participants who completed regular resistance training reduced their body fat percentage by double the group that only engaged in aerobic training. The same study showed that strength training increased lean muscle mass by an average of 1kg where the aerobic training group actually lost lean muscle mass.
Another downside to steady state cardio is that eventually the body will start to adapt to use energy more efficiently during aerobic exercises meaning it becomes less effective for weight loss. Unless you increase your intensity, run faster or cycle for longer you will inevitably reach a plateau.
What about hormones? Excessive cardio can also elevate the body's cortisol levels - a hormone that is involved in the body's metabolic processes. An excess of cortisol can wreak havoc on the body. For example, high cortisol levels influence your cells to become resistant to insulin, making it more difficult to break down fat stores. Furthermore, elevated cortisol can lead to an imbalance in hormones that regulate hunger, making you prone to sugar cravings. And we all know there's nothing like that feeling of guilt when you overdose on a sugary sweet when you've just spent hours working out at the gym!
IF YOU CHOSE CARDIO - GO HIIT (High Intensity Interval Training)
"But I feel like I've worked harder if I'm really sweaty at the end of a workout."
I hear this a lot. Sure, there's nothing quite like the sweat dripping off you to make you feel like you've worked your butt off! It's like proof of your self-accomplishment. But trust me - when you are banging out those last few sets of squats or deadlifts your heart rate will be pumping and the sweat will be running!
However, if you are going to do cardio activity, chose interval training or exercises that promote muscle building over steady state cardio. Let's look at some of the science behind this.
There are two main types of energy systems in our bodies: one using anaerobic pathways (weight training / interval training) and the other using aerobic (traditional cardio). Aerobic refers to the presence of oxygen whereas anaerobic refers to the lack of oxygen. Aerobic respiration (ie, what happens when we are running, cycling, etc) is aimed at burning excess glucose first and then excess fat in the body. Anaerobic respiration on the other hand, (what happens when we sprint for example) burns glucose but also stimulates the release of hormones such as testosterone, human growth hormone and epinephrine. These hormones favour muscle building and fat burning after you've finished a workout.
Good examples of anaerobic style exercise include exercises that are short-exertion, high intensity movements such as sprints, interval and Tabata style workouts.
OTHER BENEFITS OF WEIGHT TRAINING
Weight training isn't just about losing fat. There are numerous benefits to including a strength program into your regime:
1. Injury prevention
Weight training is a great method of injury prevention for a number of reasons. Firstly as the movements are more stationary in nature it gives your joints a break from constant impact that comes from running or other high impact exercises. Secondly it strengthens the connective tissues around bones and joints which helps prevent the risk of injuries to muscles and ligaments. Last year I tore both a tendon and ligament in my right shoulder. I tried physiotherapy, sports massage and various anti-inflammatory treatments but nothing worked. I struggled with the pain for 6 months until I developed a weight training program to strengthen the muscles around the site of the injury. After following the routine for 4 to 5 months the pain completely disappeared and I've noticed far less minor muscle injuries in general as a result.
2. Prevention of osteoarthritis and osteoporosis
From the age of 30 we start to lose bone mass. This is even more evident with post-menopausal women due to a decrease in estrogen levels. This in turn is associated with an increased risk of osteoporosis - a condition in which the bones become brittle and more prone to fractures. Weight bearing exercises are one of the best methods to increase bone density.
3. It makes you stronger
This seems like I'm stating the obvious but don't underestimate the benefits of building strength. Ok sure, you can have bragging rights about deadlifting twice your bodyweight but think about how this transfers into your daily life. Everyday tasks like lifting, carrying and walking uphill (what we Hong Kongers know all too well...) much easier.
For optimal fat loss and lean muscle gains prioritise strength training over cardio
If you still enjoy cardio opt for interval training over steady state cardio
More muscle = higher metabolism, therefore when you begin to build muscle you'll be burning more calories even when you aren't at the gym
Weight training brings many benefits, not just fat loss
TRY IT AND SEE!
So, if you have noticed that you've reached a plateau with your current exercise routine or are wanting to shed those last few stubborn kilos why not give weight training a try?
Of course it's also important to remember here that what you eat is key to fat loss. I'm not saying you can lift weights and eat anything you want and expect to lose weight.
Not sure where to start? Check out your local gym and look for qualified personal trainers who can help you with an initial training plan. Aim for a minimum of 3 days a week of strength training and a healthy diet. For more detail on heathy eating guidelines check out the Nutrition section of my website.
Boutcher, S. H and S. L Dunn (2009) Factors that may impede the weight loss response to exercise-based interventions. Obesity Reviews 10.
Bryner, Randy W et al. 1999. Effects of resistance training versus aerobic training combined with an 800 calorie liquid diet on lean body mass and resting metabolic rate, Journal of the American College of Nutrition, Vol. 18, 115-121.
Willis L. H (2012). Effects of aerobic and/or resistance training on body mass and fat mass in overweight or obese adults. Journal of Applied Physiology 113, 1831-1837.