How do I know when I should lift heavier weights?
First, let’s unpack WHY you’d want to go heavier with your weights…
Within reason, the heavier loads you lift, the more pronounced your fitness outcomes:
You’ll do more mechanical work and therefore burn more calories (which can contribute to fat loss)
You’ll provide a bigger global challenge to the body, which lead to a modest “afterburn” effect that increases total calories burned, as well as provides a training effect for the heart and nervous system
You’ll provide sufficient stimulus to gain muscle (if you’re eating enough food and doing enough total volume of training)
You’ll be stronger for everyday life
When your goal is general health, sex appeal :-), and happiness, we don’t need to be powerlifters. And once you’re a regular trainee, we don’t want to shoot for a personal record each and every workout. At a certain point, your strength gains will plateau unless you implement specific programming protocols that are beyond the interest of your average person just looking to be fit.
On the other hand, if we get comfortable lifting the same weights all the time, we can inadvertently lull ourselves into fitness complacency. So if you’re a non-performance focused person merely using fitness to live your best life? There’s a time and a place for seeing what gas you’ve got in the tank and pushing up your weights.
So let’s now address this question: How do you know when the weight is TOO heavy?
When you’re using a well-designed program you’ll usually have a specific number of reps to hit in a given set when weight training.
How do we know when we should stop a set and not shoot for any more reps? Generally we look for three things that suggest a set should end. While it’s helpful to have an outside eye to keep you honest, you can also look out for any of the following three signs:
The weight slows down in a dramatic fashion
The range of motion shortens/ you’re no longer doing complete reps
You’re unable to maintain solid technique*
*This last one is the most subjective, as there’s room for debate as to how much variance you can allow with technique.
On the one hand, if your technique is letter perfect on the very last rep, you are almost certainly lifting too light for a true working set.
On the other hand, allow too much slop in your movement, and you can engrain subpar movement patterns that can lead to injury over time. Furthermore, we don’t want to push every single working set to failure. (Again, this is all a bit subjective; this is why having a coach is so helpful!)
And with that, we return to our original query: How do I know when I should go heavier with my weights?
Provided you’re not seeing any of the above mentioned signs that your set should stop, the best way to know is to periodically “rep out.”
Let’s say a set is prescribed for 10 repetitions. Your chosen weight feels kinda hard, but you suspect you may have more gas in the tank. This would be a great time to take a single set and see how many reps you can do before reaching failure and can no longer complete another repetition.
If you were truly only able to do 11 or 12 reps before reaching failure? Then maybe the weight you’re using is ok.
If you were able to 27 before reaching failure? Definitely time to grab heavier weight!
REMINDER: Training to failure can serve its place in your training, but will always have a cost on the body. We usually like people to leave a rep or two in the tank most of the time for most fitness goals. So while you can and should periodically “rep out” to make sure you’re not lifting too light, don’t get in the habit of doing this on every single set forever and ever amen.
A final point: there’s a massive psychological element to the weights people choose.
In my experience working with every day people (non performance-focused athlete types):
20% of people tend to go too heavy, get too attached to numbers, and push past the point of acceptable technical degradation
20% of people tend choose the appropriate weight to create a solid training effect
60% of people tend to go too light; either because they’re not used to the discomfort of lifting with intensity or they don’t want to/ don’t feel mentally safe to push as hard as they’re capable
And at the risk of making this all even MORE complicated…
It’s important to appreciate that “too heavy” or “too light” can be assessed best in light of progress towards the goal in question. A choice of weight could be too “too light” to make you a successful powerlifter, but totally appropriate to build bone density and enough strength to live your personal best life.
Admittedly, the above 20/20/60 observation is NOT a scientific breakdown: just an observation. However, the key point is that some people do actually lift TOO heavy, and the majority probably lift too light.
Happily, now you’ve got a framework for thinking about this and applying it to your training. Go get 'em!