What Do You To Prevent Muscle Cramping During Games?

Personally I try to not get off the couch.

I think he's getting too much water. May be leaching electrolytes.

Also consider something like a keto mineral supplement. They help my cramping when I'm in ketosis.

I walk very deliberately through the concourse...and take my time getting up and down the stairs to my seats.  

When the time comes to stand up or sit down, I move very slowly, brace myself with at least one hand on the bench, and make a noise that is appropriate to the level of effort.  

Bananas (insert bananas cramping gif from the blue jays pitcher)

Mustard packets.  Nothing better!  Seriously.  Do some research!  Game changer!!!

If he’s cramping due to dehydration, this stuff has been a game changer for my son who suffers from migraines when he’s dehydrated.  https://a.co/d/9HN4h1G  just a capful mixed into a drink daily helps keep him regulated.

Potassium, especially if it's not included under "electrolytes".

They actually sell pickle juice (separate from jars of pickles) for this purpose, I picked one up the last time I was in Wal Mart to try it but mercifully no leg cramps for a few months.

I see a lot of ads lately for Hyland's Leg Cramps but that's another product I have not tried.

When I'm walking in the worst of the hot/humid summer days I drink LMNT - they are just salt and electrolytes but I like them. 

Not suggesting this as the end all be all, but this is an article from their web site about cramping.

https://science.drinklmnt.com/did-you-know/what-causes-muscle-cramps/

Pedialyte was a game changer for me. Not bad for hangovers too.

salt packets and more water was the military's answer to cramping.... but then again..... 900 mg ibuprofin tablets were handed out like pez, so they might not have been giving the best advice for day to day medical issues.

Pickle juice has been the #1 most helpful thing for my players over the years. We had one kid in particular who used to get terrible cramps, but once we got him on the pickle juice train, the problems went away completely. (He was the fastest player I've ever had, so it really sucked when he would cramp up and we would lose him for a stretch.)

Try Ultima. Sugar free and filled with all the neuro elements ( magnesium calcium potassium and other schtuff) it is a lot of salt. 

I usually don’t cramp until dehydration sets in Sunday. Processing a dozen land sharks during the game will do that to ya. 

Hydration should start the day before a competition. Also, as noted elsewhere, bananas.

I add Himalayan pink salt and cream of tartar to my water. I drink a gallon every day.  I also workout twice a day. Another thing I'd look into is he getting enough sleep. 

Stand up and get your arms pumping for "I Can't Turn You Loose"!

I haven't perused the responses but one really needs to start hydrating way before game time. And one wants to find that balance so that one doesn't find themselves wanting to urinate more so than often. Unfortunately, one is always behind the curve when it comes to hydration during excessive exertion.

Pro tip: do not include coconut water unless you want to add explosive diarrhea to the sidelines.

1.  Water:  Let's get something out of the way.  The whole "water toxicity" thing is a disingenuous meme.  The premise is that if you drink too much water without replenishing electrolytes, you'll throw off the mineral balance in your bloodstream, which can lead to dangerous situations.  As long as you take water and electrolytes together, in balance, there is no upper limit to water intake -- you have to do something insane like literally rupture your stomach to harm yourself.  So drink drink drink, BUT keep the water/electrolyte ratio balanced.

Speaking of which:

2.  Electrolytes, Salt, Magnesium, Pickle Juice, Bananas:  These are all the same bucket.  When you sweat you lose various ions like sodium, magnesium, calcium, and potassium:

• Calcium and magnesium serum levels are very tightly regulated by the body (bad things happen when you lose serum ion balance).  Excess is stored in bone so you won’t lose enough in any single workout to worry about.  HOWEVER, be sure to replenish through diet afterwards so you're not deficient -- because of the ultra-tight regulation, you won't feel it until you've done serious damage to yourself (albeit after months of dietary deficiency), and you can't replenish quickly.  Calcium gets the press because of the milk industry's marketing, fine, but magnesium is just as important -- literally, as in, you should be consuming magnesium and calcium in 1:1 ratio.  Mg sources:  seeds, nuts, whole grains.
• Sodium (salt) and potassium, more of it's in your blood and thus lost to sweat.  On a hot day and/or when chugging pure water, levels can drop dangerously fast.  Look for sports drinks with both.  As for food, everything has salt so just be sure replenish potassium afterwards; you don't want to put a banana in your stomach during a hard workout or it's likely to come right back up.

3.  Stretch stretch stretch.  Helps with both prevention and mitigation.  Some cramps are just working a tight muscle.  And also, when cramps do happen, it sure helps to be loose!  I've gotten a cramp on an already-tight muscle and the pain was screaming agony.  Stretching also helps prevent and attenuate contact injuries (makes sense -- you take less damage when you're bendy).

• Stretch every muscle.  Not just the ones you think you'll use.  For example, even if you're mostly running around, you use core & back muscles for stability and arms as counterweights.  I've finished a day of sports with my neck surprisingly sore -- what's keeping your noggin stable all the while?  Also you never know what'll get hit if there's contact.  Go top to bottom or vice versa so you don't miss anything.
• After stretching every muscle, go back over and re-stretch ones that are particularly tight.  Depends on the individual, but my abs and calves tend to be difficult to loosen, so I'll put an extra 20-30 minutes into those, especially if it's chilly.
• Yoga has some excellent stretches.  Don't worry about what they look like or your priorities are all out of whack.  The Michigan football team has performed yoga in public.

Organic coconut water and natural cherry juice to help with inflammation. 

Magnesium does help but it is not a cure-all. You left out stretching all of the leg muscles. This needs to be a daily thing. Before, during and after all practices. Look into buying a rolling stick. This will flush out the lactic acid that forms from exercising. I do it in the evening before bed. I took a rolling stick with me before a race which also help keep the muscle tone very loose. 

Uber leans has nothing to do with this issue, in fact, their legs are carrying less weight or the problem could be much worse.

Just google- runner's rolling stick, and a number of products should up. Also google-leg cramps or chronic leg cramps, Web MD might have some insight.

Good luck. If all of this fails, they should consult a physical therapist.