Episode 16 – Nutrition for Making Weight in Weight-Class Sports

Key Topics Covered

Why Do A Weight Cut

  • Having more size and muscle than your competitors is a huge advantage in weight-class sports.
  • If you can do a weight cut that has low/no negative impact on performance, then the advantages obviously outweigh the downside.

Who Should Be Doing Weight-Cuts?

Conor McGregor Weight Cut
  • Typically really only relevant for people who are competitive and compeating at a high level.
  • Arguably, they should not be done by lower level athletes.
  • That being said there are levels to this. Is it really an issue if a hobby powerlifter cuts 2% of their body weight to make a specific weight class? That is not that drastic and there are minimal downsides. There is a difference between that and a >6% cut for example.

How Much Can You Cut?

  • There is minimal research on powerlifters. But there is research on fighters showing that you can cut ~5% of body weight the week of a fight, if done well and with a good rehydration process, with no loss of performance and with only a 4hr weigh-in.
  • We work with powerlifters who have 24hr weigh-ins. This means that theoretically, 5% weight-cuts and no loss of performance is pretty realistic. That is a long time to rehydrate.
  • This is not super clear cut though. There is individual responses and not all studies have been this positive on this topic.
  • If you only have a 2hr weigh-in, it is probably not worth doing a larger cut. There is not enough time to rehydrate effectively. Even 2% weight loss due to dehydration significantly reduces performance.

Variables You Can Manipulate

  • People often overemphasise one variable e.g. water. But since >2% dehydration leads to loss of performance, we probably want to pull from other areas. Using multiple variables means we do not need to dehydrate as hard, which then makes the rehydration process easier and more likely to get back within 2% of original body weight.
  • Variables to manipulate include fibre, food volume, sodium, carbohydrate intake AND water intake.


Glycogen and Water
  • Every gram of glycogen you store, you typically store ~3ml of water. Therefore decreasing carbohydrate intake not only reduces glycogen weight and food volume weight, it also indirectly reduces water weight too.


  • Fibre does not effect performance short term. Therefore every gram of fibre is an added gram of weight that does not have any role in performance. It makes sense to go low fibre during a weight cut.
  • The caveat to this is that you still obviously need to avoid constipation, since that adds weight.


  • Sodium also makes you hold onto water. But there is a lag effect. If you increase sodium rapidly, you hold onto more water. If you decrease it rapidly, you excrete more water.
  • If you go high sodium for a while, this becomes the new baseline. Your body starts excreting water as per normal and makes the assumption more sodium is coming in. If you then drop sodium, you continue excreting water as if your body was expecting sodium to come in and offset this. Basically, it can make sense to go high sodium for a bit, and then drop it a few days out. It’s kind of like “tricking your body” into excreting more water.

Food Volume

  • Obviously food has weight. If you eat more food, that weight is sitting in your digestive tract until it is excreted. This impacts scale weight.
  • Lowering food volume in the days before weigh-in obviously will reduce scale weight.

Thoughts on Other Options

  • Saunas can be an option. We prefer to do it through these other variables, but a sauna can be used if needed. Dry saunas are more effective for this than wet saunas, since they encourage more sweating. Obviously aim to do this as safely as possible.
  • Adding in cardio and active sweating is detrimental and ideally should be avoided. You have ideally done a good peak, so it does not make sense to add fatigue if we can avoid it.
  • Laxatives are likely going to hurt performance more than help. Stool softeners like Osmolax can be helpful if used a few days out from comp for somebody who is prone to constipation during weight cuts.

Example Protocol for a Large Weight Cut

Sunday– Low carb (<30g)
– Normal, healthy fibre intake
– Relatively high sodium intake
Body weight (in kg) x 10%
Monday– Low carb (<30g)
– Normal, healthy fibre intake
– Relatively high sodium intake
Body weight (in kg) x 10%
Tuesday– Low carb (<30g)
– Normal, healthy fibre intake
– Relatively high sodium intake
Body weight (in kg) x 10%
Wednesday– Low carb (<30g)
– Normal, healthy fibre intake
– Relatively high sodium intake
Body weight (in kg) x 10%
Thursday– Low carb (<30g)
– Low fibre intake
– Very low sodium intake
Body weight (in kg) x 10%
Friday– Low carb (<30g)
– Low fibre intake
– Very low sodium intake
Body weight (in kg) x 1%
– No food/drink before weigh-inZero before weigh-in


  • Ideally, get back to the same weight you were at the start of the week. There is no real advantage to exceeding this mark, and there is potential downside to doing so e.g. just not feeling good. There is a clear disadvantage to being >2% dehydrated still by the time the competition comes around.
  • Rehydration protocol: 250ml protein shake (30g whey protein or equivalent) + 3g creatine, 500ml Gatorade/Powerade, 250ml Hydralyte. Sip on these slowly over the course of an hour. But you can/should do this for multiple hours if it was a large weight cut.
  • This is designed to maximise glycogen synthesis AND hydration.
  • After that it makes sense to move onto food, with an emphasis on carbohydrate rich foods.

Relevant Links/Resources

Useful Blog Post

Useful Studies