Heavy vs Light Weightlifting - Which Is Better for You? | Earth Science

Over to Dr. Chris Van Palleken, who has the latest research. The problem that lots of us have with lifting weights is that there's so much conflicting advice out there about exactly how much weight to lift. So there's an old weightlifting adage that goes, go heavy or go home. But recent headlines suggest that in fact lifting lighter weights might be just as effective. So what's the truth? The answer comes from a study published last year from McMaster University in Canada. 49 weight trainers were split into two groups. One half lifting heavy weights and the other lighter ones. The other key difference was the number of repetitions or reps each group performed. Now when we lift weights, sooner or later, no matter how heavy they are, we reach a point where we just can't lift any more. And that's known as failure. But it's not a judgement on your level of effort. Technically speaking, failure is to do with motor units, groups of muscle fibres controlled by a nerve that make our muscles contract. When we lift weights, lots of motor units are activated and as they get tired, more need to be used. Eventually, all our motor units become exhausted and that's when we can't lift any more. Now with heavy weights, you might reach failure after just a few reps. With lighter weights, you'll still get there, it just might take a bit longer. The key thing about the McMaster study was that because both groups lifted to the point of failure, they could be compared. So the team found that the group using the lighter weights actually gained as much strength as the heavier weight group. Now this doesn't mean that you always need to lift to failure. For most of us, the crucial thing is that you do need to push your muscles a little bit beyond what's easy. If you want to use a lighter weight, that's fine, but you're going to have to do more reps. The important thing is to have a training programme that's safe. So if you haven't done weights before, make sure you take instruction from a suitably qualified person. And if you're going to go really heavy, make sure you get medical advice before you start. So for most of us, unless you're going to be a bodybuilder or a powerlifter, don't worry too much about weights versus reps. The important thing is just to push yourself a little bit out of your comfort zone.