Have fun and create a plan

“I think one mistake people make is doing something they don’t enjoy,” says Jo. “That is probably the quickest way to quit something.” For instance, she says, if you have a goal of increasing your stamina by walking more and yet you hate walking in your neighborhood, it’ll be difficult to muster the motivation to get outside. Before you set your goal, try several activities this week and observe your level of fatigue during each. Then pick one you love and figure out how to add it to your existing routine. For instance, if you’re a morning person and you really enjoy kickboxing, see whether a local gym offers early classes. If you get bored easily and prefer home workouts, check out high-intensity interval classes from a few different instructors on YouTube.

Amp things up bit by bit

“No matter where you’re starting, whether you feel winded after walking up a flight of stairs or you want to run a faster 5K, gradual progression is what’s going to safely and effectively get you where you want to go,” says Jo. She suggests increasing either the time spent doing an activity or the intensity of the activity by about 10% every week until you reach your goal. Say your baseline is walking for 30 minutes—try to extend every walk to 33 minutes this week, 36 minutes next week, and 40 minutes the week after. Or if you wish to focus on speed and you normally walk a mile in 20 minutes, aim to do it in 18 minutes this week, 16 minutes and 12 seconds next week, and 14 minutes and 35 seconds the following week. Jo says a 10% change is helpful because it’s an improvement but not an overreach—your body can tolerate it. “Your body will change and adapt over the four weeks to allow you to actually get to a whole different fitness level by the time you’re done,” she says.

Be smart about rest days

When you pay extra attention to revving up your workouts, recovery time becomes even more important. “The body uses recovery days to heal and come back stronger,” says Jo. “Exercise is a stressor, and the body must adapt and get ready for the next stress you’re going to place on it—if you never take a day of rest, it doesn’t get a chance to do that.” Resting also gives your mind the break it needs to keep you from burning out. Jo recommends taking a recovery day after every day on which you do your chosen activity, but that doesn’t mean sitting on the couch. For a marathoner, rest might be a walk, and for a walker it might be gentle yoga. Being active, even lightly, on off days will keep oxygenated blood flowing to muscles and help joints stay lubricated, she says.

Tweak your other habits

First up: the food on your plate. “If you think about nutrition as fuel for your activity, being low on nutrition quality or quantity could impact how you feel,” says Jo. “It could affect your energy levels and not only how you feel when you’re doing the activity but also your motivation to get started.” She recommends loading up on vegetables, fruits, lean protein, whole grains, and water. And it probably comes as no surprise that the other big lifestyle habit that can affect your stamina is sleep. Your body needs at least seven hours of high-quality sleep every night to perform at its best.