Should I do weight training after not getting enough sleep?

Just one bad night's sleep can make you feel tired, stressed, and slow-thinking. All of this will make you question whether you should be lifting weights after getting little sleep, even if you don't intend to.

What a bad night's sleep does to your body

Before delving into how a poor night's sleep affects your body, it's important to understand how much sleep you really need. After all, you may have been sleeping poorly for a while and thought you were getting enough.

That said, the American Sleep Foundationpublished a report based on the most recent literature on how much sleep you should get based on your age:

Teenagers (14-17) → 8-10 hours per night.Young adults (18-25) → 7-9 hours per night.Adults (26-64) → 7-9 hours per night.Seniors (65+) → 7-8 hours per night.

So what happens to your body after a bad night's sleep? Studies have found that just one bad nightcan cause symptoms like:

More anxiety  → One study found that after a poor night's sleep, participants reported a 30% increase in anxiety levels.More stress → A poor night's sleep can cause stress in your body and can cause cortisol levels (the "stress hormone") to remain elevated for longer. And if your cortisol levels are high, your body won't be able to burn fat or build muscle as effectively as possible.More hunger → When you get too little sleep, your body produces more of the hunger hormone ghrelin, making you feel hungry even after eating. One study found that sleeping 5 or fewer hours a night can cause you to consume about 385 more calories per day.Less satiety → Poor sleep can increase levels of leptin, the hormone responsible for making your body feel full after a meal. A poor night's sleep will make you feel less full, even if you eat enough throughout the day.Less focus → Lack of sleep will decrease your attention and reduce your reaction time. This makes you more prone to exercise-related injuries and accidents.When NOT to do weight training after little sleep

If you've been sleeping poorly for several nights in a row and are feeling exhausted, it might be wise to skip your workout that day. As mentioned, lack of sleep can affect several important areas of your body. So if you've had several bad nights, it might be best to simply rest rather than accumulate even more fatigue.

Plus, if you're feeling stressed, that's just another sign it's best to skip your workout. Constant stress can leave you with elevated cortisol levels, which, as we know, is bad for the body, causing weight gain, a weakened immune system, and more. And one of the best ways to lower your elevated cortisol is by getting more sleep.

When to do weight training after little sleep

If you generally get restful sleep but have had a random bad night, there's not much reason to skip your workout if you want to go even if you feel tired.

In this context, and only in this context, you may experience unexpected benefits.

For example, if you're feeling tired in the morning and decide to workout, it can provide a similar boost to a cup of coffee. A University of Georgia study found that exhausted participants who did a morning workout experienced a more powerful boost in alertness than 50mg of caffeine.

However, research has found that there are certain guidelines you should follow to ensure your workout after poor sleep is still beneficial for your body. When doing a morning workout after a poor night's sleep, you should consider the type of exercise you'll be doing and the time of day you'll be exercising.

The type of workout you do after a bad night's sleep can impact the effect on your body.

A study conducted by a team of Australian researchers examined how a sleep-deprived body is impacted by different types of workouts.

The team compared strength and endurance training to training that requires complex skills, such as archery or tennis.

The results showed that insufficient sleep decreases complex skills by up to 23%, while endurance and strength decreased by only 5–8%. This means that going for a run or lifting weights should be fine after a random night of poor sleep.

The time of day you exercise after a lack of sleep also matters. If you jump out of bed and head straight to the gym, the effects of sleep loss will actually be minimized.

The researchers found that athletic performance on complex skills decreased by 16% if the workout was done in the morning, but by 25% if the workout was done in the evening. Similarly, tired participants who lifted weights in the morning performed 2% worse, while those who exercised in the evening performed 5% worse.

Researchers also found that the detrimental effects of exercising while tired were stronger among exercisers who lost sleep by waking up too early compared to those who went to bed too late.

This decline in athletic performance throughout the day is likely related to the body's circadian rhythm. When we wake up in the morning, our bodies release adrenaline at the sight of morning light.

Additionally, a chemical called adenosine increases in quantity as the day progresses. The more adenosine in your body, the more tired you'll feel and the harder it will be to get in a good workout.

Conclusion

Whether you work out after a lack of sleep depends on the context and your personal preference. Sleeping poorly for one or several nights will make you feel tired and stressed—this is a fact of life. However, if you've only lost one night of sleep, you can still train and even reap some benefits.

However, chronic sleep deprivation—not sleeping well for several nights—is a terrible situation for your health and should be addressed as soon as possible. In this context, if you feel constantly tired due to frequent poor sleep, it's best to skip training and perhaps use this time to take a restorative nap.