I have decided to write this post in response to a question from a friend of mine. She is concerned that she is gaining size on her legs and butt through the exercise she is doing, and doesn’t really want to. There are different types of exercise that can cause you to see an increase in size and it can be pretty complicated to give a straight answer. So I am going to try to be as clear as possible without skirting round the issues. I have to give credit (or blame!) to my husband, Pete, who is a strength and conditioning coach for elite athletes, for a lot of the information in this article. He is more of an expert than me when it comes to the intricacies of weight training!
First and foremost, there are a number of factors that can impact how you respond to exercise and training. These include:
- The type of exercise you currently do
- The volume of exercise you do (how much of it)
- Your somatotype (this is your natural build. Training can impact and change this, although a tendency remains towards one particular body type)
- Whether you are a novice, intermediate or advanced trainer
- Your age
- Your sex
- Your exercise history (the types of sports or exercise that you have done in the past)
- Your injury history
- Your nutrition
I am not going to look at all of these variables, but I will present a few key ideas that will include a number of them.
Figure 1. and figure 2. show the difference in responses to weight training between novice trainers and advanced, well-trained individuals. When novice trainers train with heavy weights but low repetitions, they generally lose weight and therefore the girth of their legs decrease. This is due to the high calorie burning effect of this type of exercise. When advanced trainers train with heavy weights and low repetitions, however, they generally gain a bit of muscle mass slowly over time. This is because they are lifting relatively heavier weights than novice trainers (because they are stronger), and they have already experienced the early adaptations that novices experience, and therefore, put simply, growth is the next adaptation to happen. One way to slow down this growth is to keep the volume of heavy lifting low. This means that you still lift heavy for few repetitions, however, you will not do multiple sets. The total amount of work done will be less. If you wish to continue lifting heavy for the strength gains, you should do something like 3 sets of 3 repetitions instead of 5 sets of 5 repetitions for example. That way you can keep the load high but the volume low.
Lifting moderately heavy weights for 10-15 repetitions is the best way to get muscle growth. These are the typical parameters used by body builders. The reason you get maximum growth in this rep range, is that the muscle is under tension for a long period of time, with the addition of a heavy load. This means that the maximum amount of damage is done, and if you recover properly, the maximum amount of growth occurs. “Time under tension” is one of the keys for muscle growth. Therefore this is the type of training to avoid if you do not desire size increase.
When lifting light weights for high repetitions, you do not experience the same physical adaptations of muscle growth despite the fact that the muscle is under tension for a long time. The reason is that the weight is not high enough to cause a large enough stimulus for growth. Less damage is done with a lighter weight, so less growth occurs as a result. The time under tension may be high, but the light weight means the degree of tension is much lower.
Nutrition plays a key role in muscle growth too. By reducing your overall calorie intake, you will get less growth as a result of training. Be aware though, that training at a high volume and high intensity, on a low calorie diet is not sustainable for long. When bodybuilders train on a reduced calorie diet in their pre-competition “cutting” phase, they are not able to train at the same intensities or with the same volumes as when they are feeding well in a growth phase. If you are smart with your nutrition and training, however, you will be able to find a balance where you can train hard and lift quite heavy, and still not grow. Make note, cutting calories does not necessarily mean cutting down on volume of food. By making smart choices, and eating plenty of vegetables, you can still reduce your amount of calories without going hungry.
If you are a relatively advanced trainer, like my friend who asked the question, perhaps you still want to lift weights but do not want to continue to see significant muscle in your thighs and butt (or anywhere!) you have a few options:
- Lift light weights for high repetitions. That way, the exercise becomes more aerobic, with the weight not being high enough to stimulate growth
- Lift heavy weights but keep the volume low. This can either mean reducing the number of sets performed in a session (as stated above), or keeping the number of sessions per week low. If you limit yourself to 1 session of heavy lifting a week, to maintain strength, and your other exercise sessions are non weight training activities, the stimulus from the one heavy session, compared to the stimulus from the multiple other sessions of different activities will not be high enough to elicit a huge amount of muscle growth. The thing you do the most of, will have the biggest effect. So if you do 1 weight training session, and 4 other sessions, the other 4 sessions with have a greater effect on your physical adaptation than the 1 weight training session.
- Lift heavy but learn to manipulate your diet to minimise the amount of growth through calorie reduction, timings of meals, and macronutrient manipulation.
I hope you find this useful. Keep trying new things but most of all, enjoy your training! Give me a shout if you have any questions