You want to do weight training but aren’t sure where to begin. You search Google for guidance – but all you find are fitness influencers pushing the idea of lifting big.
That may sound daunting and disheartening to many people. Like with most things, exercise and health are not that simple.
I’m a certified fitness trainer and specialist in exercise therapy who researches resistance training, a workout form of lifting weights. Many studies show that workouts using smaller weights and doing more repetitions (or, in gym parlance, “reps”) can be an essential key factor – but it all depends on your goals.
In short, lifting heavy is an effective way to build significant strength and bone density. But for those who can’t lift heavy or it’s not your thing, don’t think lifting lighter weights is a waste of time.
Hang on: let’s understand what is ‘heavy’ or ‘light’ in this context.
What’s heavy for one person may be light for another.
In resistance training, the load or “heaviness” of weight is generally expressed as a percentage of a “one rep maximum” (shortened to “1RM”).
A one-rep maximum is the maximum weight you can lift once successfully.
Around 80% of your one rep maximum is typically defined as “high intensity” or heavy lifting. This would allow you about eight reps of lifting 80% of your one rep maximum.
Around 40% or less of your one rep maximum is generally defined as “low intensity. With a lower weight, you can do more reps. However, the more reps you do, the less accurate the relationship becomes.
Some research studies recommend doing approximately twenty reps at 60% of your one-rep maximum (but it varies depending on the person).
Keep in mind that due to age, fitness level, or just being new to workout, it’s not possible that everyone can lift heavy. Don’t assume that if you cannot lift heavy now, you can never lift heavy down the line.
But the critical thing is this: when you train at a lower intensity, for example, 40% of your one rep maximum, you’ll have to do a lot of reps to have a positive benefit.
The benefits of lifting heavy
Doing weight training ranging from 40% to 80% of your one rep max has been found to bring out growth in muscle mass (hypertrophy). However, research studies have also shown that weight training at higher intensity can maximize gains in muscular strength.
High-intensity resistance and weight-bearing exercises are probably the most effective type of workout for retaining and augmenting bone health.
Lifting lighter? Here’s what you need to know
Research has found that doing high-rep, low-intensity exercises may counteract age-related reductions in lumbar spine bone mineral density.
If you decide to use lighter weights, you should do more reps to get the same benefits as doing heavy-weight training.
Research also has found that if you’re using lighter weights, you likely need to work out all the way until exhaustion. In other words, muscular failure is probably required to bring out muscle growth.
What about burning energy?
On average, a one-hour high-rep/ low-intensity style resistance/weight workout session may burn roughly 300 calories. A heavy workout session with longer rest periods burns approximately the same calorie as a higher rep session with less rest.
There may also be sex differences in the way in which older men and older women respond to resistance/weight training. For instance, older men may benefit more from higher-intensity programs, while older women may actually benefit more from higher-volume programs (more reps).
You may be surprised to know that low-load training is, in fact, hard. Actually, it’s uncomfortable to do high rep/ low load workouts to failure or close to it (remember: “workout to failure” means getting to a point where you actually cannot do any more reps). It needs a significant degree of willingness and motivation to tolerate discomfort.
Doing with low weights is unlikely to improve muscle growth and strength significantly. Therefore, if you choose this style, ensure you are ready to put in the effort.
The benefits of light weights include that they are portable. So, you can work out in a pleasant environment such as the beach, the park, or while on holiday. They are easy to store and don’t cost as much. For many, they are also not as daunting.
These benefits will likely make it easier for some people to stick to a regular exercise routine. For others, these benefits may not outweigh some of the benefits, as mentioned earlier, of more traditional heavy-weight training.
It depends on your goal.
The bottom line of the story? Whereas it does matter which type you do and how you do it. But probably not as much as you think.
About Author: Renu Bakshi, AKA Fitness Buffhq, is ISSA Certified Elite Trainer. He passed 
Personal Fitness Trainer Course, Nutrition Health Coach course & Specialist Exercise Therapy course from ISSA, the USA obtaining + 97% marks. He shares his experience and knowledge about nutrition and effective workouts to get you in the best shape of your life, no matter how old you may be. The author says: “For me, age is just a number!”