Do a quick search for "fitness" on Pinterest and scroll through and you'll likely see tons of pins that have been circulating for years with thousands of share that promote the same fitness rules: never miss a Monday, never go 3 days without exercise, and work out at least 3 days a week (oh, and there's a fourth one that's more of a motivational tool and less of a rule: never give up).
But the question is, do these rules actually work? And if so, why are they so important? Here's what you need to know about the science and reasoning behind them:
1. Never miss a Monday workout.
There are actually several factors that go into this idea of regular Monday workouts — a lot of it is about having a routine and creating habits, but there are also some physical benefits to. According to Daily Burn, Monday workouts give you a clean slate to start the week with and make you more likely to work out for the rest of the week, too.
Monday workouts can also kickstart your self-control, plus exercise in general can help you sleep better (and what better way to kick off the week than with a good night's sleep?). If you can get a morning workout in on a Monday, you're off to an even better start—since exercise releases endorphins, you're much more likely to be in a better mood all day than you would be if you skipped the gym.
2. Never go more than 3 days without exercise.
Much like rule No. 1, this is less of a biological thing and more of a habit-forming thing. When you stick with something long enough (and better yet, keep it scheduled in and don't skip out on it), it'll eventually become a habit that you don't ever have to think much about. This goes along with what author and expert Gretchen Rubin told Daily Burn about Monday workouts—it can be really powerful and motivating if you don't "break the chain." Biologically, nothing will really change if you go 3 days or more between workouts, but if you're trying to get yourself to consistently exercise more often, putting it off for too long will make it harder to turn it into a habit.
3. Work out at least 3 times per week.
The idea that you should work out at least 3 times per week is is largely based on recommendations from medical professionals (and trainers, too)—but it also really depends on what kind of exercise you're doing when you're working out. According to the American Heart Association, to improve your overall cardiovascular health, you should get 150 minutes of moderate exercise per week, or 75 minutes of vigorous exercise per week (or a combination of the two).
The AHA suggests breaking it down into 30 minutes of moderate exercise each day for 5 days a week, or 25 minutes of vigorous activity 3 times per week in addition to 2 days per week of moderate muscle-strengthening workouts (SELF suggests a similar breakdown). The AHA also recommends 40 minutes of moderate to vigorous activity 3-4 days per week for lowering blood pressure and cholesterol. Really, this one depends on your needs, but 3 moderate to vigorous exercise sessions throughout the week seems to be a good start based on these recommendations.