Rest days are an important part of any workout routine, since they help you to save your energy for future training days. But what counts as rest, exactlydo you need to avoid all exercise? Ill break down the purpose of these days and answer your questions about what does and doesnt count.What is the purpose of rest days?People say a lot of things about rest days that arent really true, so Id like to take a minute to separate myths from facts.Rest days actually do the following:They balance your workload. Your body can handle three hard workouts in a week if you balance that by giving it four rest days. Note that the number and type of rest days depends on how hard the work days are. If you did six days of relatively easy workouts, one rest day each week would be plenty.They help you fit exercise into your schedule. Most people cant hit the gym every day, just because we have other things to do with our lives. A three-day exercise program (with, yep, four rest days) is a lot easier for most of us to stick to than a six-day one.They take the guesswork out of easy days. If your program told you to alternate hard and easy days, you might find yourself working too hard on the easy days. But if its a complete rest day, you just dont show up to the gym, and now you know for sure you arent doing too much.Now lets talk about some things that rest days are often said to do, but that arent actually true:They dont prevent injury. Balancing your total workload can help to prevent injury, but as we discussed, rest days are one tool that can help in that balance. There are ways to safely exercise without rest days.They arent necessary for muscle growth. Its sometimes said that your muscles recover or grow when youre resting, but keep in mind that if you do a one-hour workout every day, your muscles have 23 hours to rest before the next one.They dont allow full recovery. The results of your workout take days to weeks for your body to fully recover from. We dont wait for full recovery each time, or else wed never get on a consistent schedule and never make any progress in training. Your muscles (and other body systems) can work even when theyre not fully recoveredwithin reason, of course.When should I take rest days?This depends on your training program. Any good training program, whether you get it from an experienced coach or download it from the internet, should be designed with a good balance of work and rest.If youre designing your own routine, here are some guidelines to help you know where to put the rest days. These are not ironclad laws, and lots of good programs will do things differently. But these are helpful rules of thumb to get you started:In a strength training program, each muscle group should get a rest day after being worked for 1 to 2 days. That could mean a full-body strength program where you lift Monday, Wednesday, and Friday, or a split where you do upper body Monday and Thursday, lower body Tuesday and Friday, and rest Wednesday and the weekend.In a running or cardio program, beginners should get a rest day after 1 to 2 consecutive workout days. That allows for a Monday/Wednesday/Friday schedule, which is very popular for beginners.For people with more experience, an easy day can take the place of a rest day. For example, a runner might run five days a week, but only two of those are hard workouts and the other two are easy jogs.Its OK to do two workouts on consecutive days, so long as your total work/rest balance stays the same. For example, if you cant do your Wednesday workout and you end up running on Monday, Thursday, and Friday, thats OK because you still have four rest days this week.Above all, if youre writing or modifying a program for yourself, listen to your body. Its unwise to jump into a five-day-a-week plan when you dont normally exercise at all. Its much better to start with three days, see how that goes, then consider adding more workouts and adjusting their intensity.What should happen on a rest day?Keeping the purposes of rest days in mind, you want to make sure that your rest day accomplishes what its meant to accomplish.In a strength training program, your rest days should give you a break from any serious strength training. That doesnt mean you need to sit on the couch all day, but it does mean that you probably shouldnt do squats again if you just did squats yesterday.On a rest day, you may keep up your baseline level of activity. If you normally get 8,000 steps, you can still take 8,000 steps. If you normally walk your dog, you can still walk your dog. If you work a job that has you on your feet or moving equipment all day, you can still go to work and do your job. You dont literally have to rest, you just have to keep your activity to your baseline level.Can I do strength training when Im resting from cardio, and vice versa?Once you get used to it, yes. Strength training and cardio are different enough that they dont give your body the same kinds of stress. In fact, lifters who do cardio may find that the cardio helps their muscles to recover. And runners who add some strength training may find that the benefits outweigh the lost rest time.Beginners should approach this cautiously, though. If youre doing couch to 5K and coming from a literal couch-potato life, give yourself a few weeks to get used to the new schedule before adding in some beginner-level strength training.That said, remember to listen to your body. If youre a relatively active person, and youve just started strength training, you may not find it fatigues you at all to add a little light jogging. Just pay attention to how that goes, and make adjustments as needed.Consider keeping hard days hard and easy days easyHeres another not-ironclad rule: some coaches advise that its better to stack two workouts on a hard day to free up some rest time on a different day. That could mean doing a run and a strength workout on Tuesday so that you can take a true rest day on Wednesday. If youve been ramping up your exercise volume and find yourself longing for a rest day, try this approach and see if it feels better to you.Can I walk on my rest days?Yes, because walking is light enough exercise that its not likely to fatigue you too much for the training to come. If you dont normally walk much, start with just a short walk and see how that goes. If you normally walk a lot, you can pretty much walk any amount you want on your rest days.Can I do yoga on my rest days?Yes, if you keep it relatively light compared to your harder workout days. A rest day is a good time for gentle flexibility work, light strength work, and just keeping your body moving a bit. If you feel like your yoga session does that, perfect.I would only recommend not doing yoga on a rest day if your idea of yoga is a really tough power yoga class, or if it involves an extreme level of stretching. In that case, you should classify it as a hard workout and make sure that you get some rest from those hard workouts as well.Can I do active recovery on my rest days?Depends what that means to you, but probably! Mobility work, foam rolling, light yoga, walking, and easy swimming can all fall under the umbrella of active recovery. Just remember that active recovery isnt defined by what kind of thing you do, but by how hard it is on your body. If youre a swimmer and find it relaxing to do a few easy laps, then yes, that can absolutely be a recovery activity. But if youre new to swimming, and you find yourself flailing in the water gasping for breath, that is not a recovery activity. Use a little common sense and youll be able to figure it out.