While 30 minutes a day of cardiovascular exercise is enough to reduce your actuarial risk of bad things like diabetes and heart disease, it takes about six hours a week to be in decent shape and ten for good shape. Do cycling, cross-country skiing, rowing, running, snow shoeing, stand up paddle boarding, and/or swimming 5-6 days a week to get to that total. The net impact on your schedule can be negligible – it’ll give you mental white space so you don’t wait as long for creative “aha!” moments, and make you sleep better so you need less. Bicycle commuting can be especially time-efficient with time riding replacing time driving – in Silicon Valley you might swap 1:20 driving both ways during rush hour for 1:50 riding. Ease into it, where adding 10% more time each week is a rule of thumb. Have balance – even Olympic athletes spend 90% of their time at low intensity. Have a lower volume/intensity week out of every four.
Get enough sleep. You need it for optimal mental and physical function. A hard stop at night and same schedule on weekends makes this easier. Go to bed early enough you wake up naturally when you want to with enough sleep instead of racking up sleep debt with an alarm clock.
Don’t eat too much. Don’t eat entire servings because they’re usually over-sized for one person. Don’t snack on free food when you’re not hungry. 10 nuts totaling 100 Calories a day add up to 10 pounds a year. Only eat enough to be sated 30 minutes after your last bite, not until you’re full because your apetite lags behind. Only eat when hungry. Always eat when hungry so you don’t get too ravenous to control yourself.
Doing that I shrunk from 205 to 135-137 pounds (at 5’9.5″ that’s professional cyclist size), dropped from a 36″ pants size (probably 40″ around) to a 26″ waist measured with a tape measure, stopped snoring, sleep 1-2 hours less, have much more energy, and am usually more relaxed than I was as a more sessile person after a few beers. I’m in better shape than I was at age 20 a couple decades ago.