When it comes to exercising, there is a lot of information on whether to lift heavy weights or not – and it can get pretty confusing, fast. Some people choose heavy weights when they want to gain more visible muscle or "bulk" up, and some people are afraid of lifting heavy weights for this very reason.
Unfortunately, many women still believe in the myth that lifting heavy weights will give them bulky muscles, so they choose light or no weights and go to classes that promise "long, lean muscles" instead.
But is any of this information even true? (Spoiler alert: not really). Choosing the right weight for you to lift is all about how you exercise, not the number on the dumbbells.
Everything comes to the ropes
People lift weights with the goal of making their muscles stronger (and, for some, to get the bulky biceps or lean arms). For those who want to develop large muscles, they are likely to choose a heavier weight, while people who want to become lean will stick to something smaller.
The truth is that there is no correct strategy – both are valid choices. Lifting heavy dumbbells, kettlebells and barbell will surely make you stronger. But lighter weights can help you get stronger too – it can only take you a little longer.
Everything comes down to one important factor: muscle fatigue. This means that the goal of your workout should be to work your muscles to the point of fatigue (ie when you can no longer do another rope) no matter how much weight you use. So whether you do five dumbbells with 20 pounds or 20 reps with 5 pounds weight, as long as you get to the point of muscle fatigue, you get stronger.
And science backs this up. A 2010 study found that a group of men who lifted heavy weights to "failure" or muscle fatigue gained the same amount of muscle and improved their strength as much as the other group lifting lighter weights for more reps. This study in 2016 found the same results.
Some workouts that you can do that use light weights include a barre class, yoga sculpture, Pilates or "sculpting" classes. Or a light workout might look like doing bicep curls with a lighter weight (like 8-10 pounds) until you can't lift more with good form. At the other end of the spectrum is squatting with an Olympic barbell, which fatigues your muscles after just a few reps.
The benefits of lifting light weights
What are some reasons why you might choose to lift light weights over heavy ones? If you are new to working out or starting a new fitness program, light weights can be a good choice. "Someone can choose to train with less resistance when they learn the shape of new exercises. Then once they have got the shape and feel comfortable, they can increase the resistance," says fitness trainer Heather Marr. Other things to consider are that light weights are a good option to reduce the risk of injury – you just have less tendency to injure yourself with a weight of 5 pounds compared to 50 weights.
You can also include light weights in other types of workouts to provide more resistance and keep your heartbeatup. For example, in some of my dance cardio classes we do dance routines while we have a 2- or 3-pound weight, which gives resistance (my arms are always burning at the end) and makes cardio training harder. When I'm done with the song, my arms feel like they can't hold the weights of 3 kilos – even less something heavier.
As I said, lifting heavy has its own set of advantages and can definitely increase the challenge if that's what you are looking for in your exercise routine.
What are the benefits of working out with heavier weights?  If you are thinking of gaining muscle and increasing your strength in the most efficient way possible, lifting heavy weights is a good option for you. Gaining strength will all fatigue your muscles, and heavy weights will get you there faster. It only takes longer to get tired when curling a 5-pound weight compared to a 25-pound dumbbell. "Heavy compound exercises provide the best value for your money. You can use the heaviest load possible and work more muscle in less time, making them effective and also beneficial for weight loss," Marr said.
And if you are looking for more cardio in your routine, you can do it with heavy weights if you are strategic to your weight training workouts. "You can even execute the exercise circuit style in a row and get the added benefit of conditioning work all in one," Marr said.
How do you know when to lift heavier?
Say you've been training for a while and the 5-pound weights don't really feel like they're doing anything. What should you do? Go heavier, of course; just make sure you move at your own pace.
According to Marr, you should work your way up slowly over time and always try to challenge yourself. "No matter what rope interval you raise in your work sets, the last representative of two should be a serious challenge and struggle. If it is not, you know you have to increase the resistance," Marr said.
All scientific and training advice aside – the most important thing about your fitness and exercise routine is that you do something consistently. And the chance is that it's the most fun and engaging workout for you, no matter what kind of weights you use.