My answer? Why do you want to?
Mine has been mostly 80/50 most of my life. It got to the "normal standard" when I was pregnant, and went up slightly(85/55-90-60) after I gave birth, but stays relatively low.
The adding salt to the diet is a double edged sword, as it can permanently raise BP, and if after he tapers off his medication(only by a doctor, as incorrect weaning will also mess it up), will raise it to too high.
Natural "sports" drink.
One lemon wedge(squeezed slightly into the glass),
one teaspoon of blue agave nectar or a packet of stevia powder(I use truvia),
one pinch of salt
Place into a 32 oz container of water. Mix well.
Lemon balances out the super sweet of stevia(a little goes a long way, and you may find he needs or wants less), and also balances out the slight maple-like taste of agave nectar(a better and sometimes cheaper alternative to pancake syrups, as a little goes a long way), and both sweeteners are natural, and if they are diabetic friendly, not harsh on a growing body, so yeah, no artificial sweets or colours or flavours.
He's going to need to learn how to GET UP SLOWLY. My one issue was if I sat down for a while, then got up quickly, I'd get dizzy.
When working out, your BP will elevate, but when I was younger, my body would quickly try to return to low. I had to learn to cool down and stretch a bit longer than most(hence my taking yoga) after running to prevent after workout dizzy spells. He will need to learn how his body reacts, and cool down longer than most.
Caloric intake. Healthy foods--fresh veggies and fruits(or flash frozen prepared properly), Whole Milk, Whole grain breads and cereals, sensible , lean meats and fish.
Teenagers and young adults, especially an athlete like your son, needs a slightly higher caloric intake to "feed" his muscles, as they are taking the most of his food intake for conversion. BTW, unless his metabolism is Superman awesome, weight gain will occur as muscle weighs more than fat. If you don't feed the muscles, yup, you guessed it, dizzy from lack of calories.
When I ran a lot, My intake went from the standard 2,000 calorie intake to 2,800 calories. I was sensible, and ate healthy fats(as you need about 600 calories a day from fat to feed your body). I also had healthy snacks. I drank smoothies with whole milk, tofu, and used frozen fruits instead of ice. I ate home made "trail" mix made from things like cheerios, unsalted nuts, dried grapes and cranberries and other fruits we dehydrated ourselves. I drank lots of water and barley tea(handful of roasted barley boiled in a pot of water).
One thing to remember about medication...it takes about a month for your body to adjust to it, and your body to discover how to metabolize it. It's not until then that you can decide if the pros and cons balance each other out.
Looking at the doctor's comment on blood volume...
When at the doctor's, have your son's hemoglobin count looked at. Liquid Chlorophyll(commonly recommended to boost pregnant women's blood volume) might assist in increasing blood volume if he is slightly anemic(also a dizzy spell trigger). It's a natural plant iron supplement available at most health food stores. Pricey, but a bottle typically lasts me four to five months, so spending $20 on a bottle is not bank-breaking. Two tablespoons in his morning OJ. It has no negative issues if you opt not to use it later, as it's just a green supplement.
Hope these help.
Agree or disagree, as always, it's...
Just my 2cp.