Here I’m going to talk very generally about why weightlifting has weight classes, what they are and how to decide which one you should be in. My opinions here are very much my own thoughts only. 

Weight classes are part of the reason people like myself rabbit on about weightlifting being a sport for everyone; they enable a broader range of physical sizes to be competitive in the sport. If you think about a sport like basketball, you immediately imagine tall athletes. Weightlifting? You can be tiny or massive and all good, get amongst. Having this range also enables the sport’s global reach, as the relative physical norms of all countries can be accommodated (e.g. speaking very very generally, we see relatively more Asian nations competing in light weight classes and European nations competing in heavier weight classes). 

So the point of weight classes is to offer a comparatively level competition playing field for the greatest possible number of athletes. What they are, is more of a bodyweight window you can sit within.

There are 10 weight classes available at all age grades of the sport. These differ between males and females, and are scaled down for youth age grades where athletes are still growing and typically lighter. 

The Youth weight classes are as follows;

Female: 40kg, 45kg, 49kg, 55kg, 59kg, 64kg, 71kg, 76kg, 81kg, >81kg

Male: 50kg, 55kg, 61kg, 67kg, 73kg, 81kg, 89kg, 96, 102kg, >102kg

The Junior and Senior (and IWF Masters) weight classes are;

Female: 45kg, 49kg, 55kg, 59kg, 64kg, 71kg, 76kg, 81kg, 87kg, >87kg

Male: 55kg, 61kg, 67kg, 73kg, 81kg, 89kg, 96kg, 102kg, 109kg, >109kg

What weight classes are available to you as a youth (an athlete between the age of 13-17) in any given competition is going to be dependent on what age categories are recognised at said event. Confusing? Yes it is here’s why.

The young age categories in weightlifting all overlap. Each year, the following is at play

A youth athlete is anyone who turns between 13 and 17 that year

A junior athlete is anyone who turns between 15 and 20

A senior athlete is anyone who turns 15 or older

The 15/16/17 year olds overlap three categories, which is why what the event recognises is relevant. For example in New Zealand we allow 13 and 14 year olds to enter the North and South Island Championships, even though only Junior and Senior categories are recognised at these. This means for the purpose of those events all youth-aged athletes are considered as juniors and sorted across the Junior/Senior weight classes. In contrast, our Secondary School Championships only recognises Youth weight classes, even for senior students who turn 18 that year and technically have aged out of Youth. 

Fun isn’t it. 

Which weight class are you?

In the truest sense, your weight class is the one within which your body weight sits when you weigh in to compete. For example for adult females the lightest class is 45kg. That means at weigh in (which takes place between 2 and 1 hours before competition officially starts) every participating athlete in that class must jump on the scales (in their suit) weighing no more than 45.25kg (as 250g is alloted for the suit). From there the window is between the the heaviest and lightest limit (the lightest dictated by the class below), e.g. females the 49 class must weigh in between 45.01 and 49.25kg, in the 55 class between 49.01 and 55.25kg, and so on, until the supers (>87kg) where you must weigh 87.01kg or more, with no upper limit. 

Often, an athlete will walk around pretty comfortably within a weight class. If my bodyweight sits consistently between 66-68kg, then I am squarely within the 71kg class (between 64.01 and 71.25kg). It gets a little less clear if as a male my weight sits between 95-97kg, and I could realistically be a full 96, or a very light 102. 

If new to competing the biggest thing here is to be aware of what you normally weigh, including your normal range (as it’s more likely to move up/down on a day to day basis than to be exactly the same). This is particularly important for those females who experience noticeable weight fluctuations across their menstrual cycle that might move them into a different weight class at different times.

Whether you naturally sit within or across a couple of weight classes, there are a number of factors which might mean you compete in multiple weight classes over the course of your time in the sport. I’m not going to talk about rapid weight loss (‘cutting’) strategies here, just the things that can influence what body weight you walk around and therefore the weight class you would sit within without any pre-comp manipulation. 

Natural influences on bodyweight/weight class

Body Composition

One of the pathways to being stronger is to increase muscle fiber size (i.e. bigger muscles). All else being equal, more muscle will make you heavier. In some cases as athletes get into weightlifting they will not experience weight gain, or may even slowly become lighter as a result of concurrent fat loss/leaning out through training. The size of the effect here is going to be related to how much muscle and fat mass you had before you started weightlifting (let alone energy balance, training stimulus, age, genetics, recovery etc etc).

Age

If you’re young enough when you start weightlifting, the physical growth associated with biological maturation will result in being heavier over time. Remember this includes filling out as much as it does getting taller and is a process that can take place through to the mid-20’s. At the other end of the spectrum as we get older, athletes can slowly become lighter through a natural decline in muscle tissue and bone density (assuming fat mass remains the same).

Training Age

If over a period of years you are an athlete consistently training with the intent of lifting the highest possible number of kilos, you are going to be seeking to maximise three capacities; the efficiency of your lifting (technique and use of momentum), your neuromuscular strength (ingraining of movement patterns, ability to recruit muscle fibers) and actual available muscle to produce force. It is not unusual over a period of years as muscle mass slowly increases in the pursuit of the above that athletes will end up in a higher weight class. This is particularly common with athletes who come into the sport with comparatively less initial muscle mass (i.e. a lower general athletic training age). 

Training volume

This is an interesting one as can be a real double edged sword, and training volume changes might not happen intentionally. You could get ill or sustain an injury, you could get busy for a period of time with work or study, you could have more opportunity to train as a result of a change of circumstances, you might change clubs/coach/programme and just follow what you’ve been given. More training in theory provides more opportunities to place the body under and adapt to training stress (i.e. get better, build muscle). More training also means more training related energy expenditure and less opportunity to recover. Everyone will have a sweet spot although some athletes never find it… It’s really important to recognise that nutrition and recovery capacity are going to dictate what effect a change in training volume might have. Assuming all training is being adequately recovered from and there is no associated change in nutrition, an increase in training volume may cause no change in body weight (just changes in composition with loss of fat mass and increase in muscle mass) or weight loss (due to increased energy expenditure), while a decrease in training volume in this scenario will be most likely to cause an increase in fat mass as a result of decreased energy expenditure.

Intentional influences on bodyweight/weight class

Optimal Performance

In theory each of us has the ideal body weight/composition where we have maximal available force generating capacity (strength) without compromised mobility or speed to move around and receive the barbell. I am not sure that there is necessarily any method of determining what this is for a given person besides learning from what others have done and trail and error. An athlete might seek to gain weight in order to develop their strength/increase muscle mass, but ultimately decide they are better placed in a lighter weight class because while they might not be able to sustain as much muscle mass/absolute strength, they can move faster and ultimately lift with great efficiency. All things are a trade off and as a result body weight manipulation may take place to try ensure the collective best circumstances for the individual. 

Performance Opportunities

If I’m betting I would say that opportunities have more influence on weight class selection than finding the personally optimal body weight/class. A very obvious example would be at the elite level, the number of male athletes who have moved into the 89 and 102 classes in the last year. Why? Because these classes were not offered at the Tokyo Olympics, but they will be at Paris (while those around them, 81/96/109 will not). Other reasons might be uneven weight class stacking- if a nation has three 71kg female athletes at representation level and only two can represent in that class (which is standard in international events; limit of 10 athletes total in the team per country and 2 per weight class), it makes sense that at least one of these athletes moves down to 64 or up to 76. In a situation like this a move might be mandated by the national federation (i.e. move up or you won’t be selected). Other times, athletes might identify that they will have a better chance at a higher ranked performance or grading and will elect to move themselves (e.g. an 81 female might cut to 76 if it offered a more realistic chance of achieving an International total). 

Personal Health & Wellbeing

Sometimes athletes will choose to change what weight class they sit within for reasons not related to performance. If an athlete reaches a point where they are finding it too mentally stressful to continue managing their nutritional intake in order to stay within a lighter weight class, they might choose to move up in order to relieve this even if it results in being less competitive. The same may happen if an athlete feels like maintaining a lighter body weight is no longer healthy over time.  Aesthetics and comfort can also play a role. An athlete might have more opportunities in a higher weight class but simply feel too uncomfortable (physically and/or mentally) to be willing to stay that heavy. Equally an athlete might not enjoy the leanness associated with a lighter weight class and choose to move up. Reasons can be very individually specific and complex. 

So there you go. Not a very straight forward topic, and you’ve now read through the whole thing and realised I’ve not given you any advice whatsoever. Sorry, it’s just too personal a thing. My understanding is that there has been a fair amount of work done towards the identification of recommended weight classes to end up in based on height and anatomical proportions. I am not sure quite how far that’s gone in terms of putting out associated recommendations, but know I would be hesitant to use them as anything other than a frame of reference anyway.

At domestic level in New Zealand you will see a huge variety of physiques within the same weight class. Hopefully this piece has offered some background on what factors may have contributed to that variety ending up in there within the same body weight window, and if a competing athlete, has given you some awareness around weight class selection for yourself over time.