Why Do I Feel Weak at the Gym Some Days? (Solved)

Have you ever noticed that you feel weak at the gym some days?

Well, as it turns out there are some extremely obvious reasons for this, as well as some not so obvious.

So, I’d like to explain why you feel unbelievably strong some days, whereas other days you can barely lift a thing.

Why Do I Feel Weak at the Gym Some Days?

There are various reasons why you feel weak at the gym some days. The most obvious of these are related to your food and water intake, as well as your sleeping habits. Basically, if you’re dehydrated, lack glycogen in your muscles, or not getting enough sleep you’re going to find it more difficult to train. Additionally, the time of day you train, and even your overall mood, can impact on your strength levels.

1. Are You Sleeping Enough?

A Man Sleeping on the Floor

I can’t emphasise enough just how important sleep is to us as human beings.

Forget working out at the gym for a moment – if you’re not getting enough sleep it will impact pretty much everything you do throughout the day.

Therefore, a lack of sleep can affect how you work, how you eat, what you eat and drink, your mood and emotions, and of course, how you train in the gym.

Sleep deprivation typically leads to the body giving up when it would normally be able to push harder.

This is especially true in the gym environment when you’re performing compound exercises.

If you haven’t got the recommended 7-9 hours sleep you’ll generally find that this can lead to a decrease in reps and sets.

With that being said, if you are going to workout on a sleep deprived day then do it as early as possible.

Basically, the longer you wait to workout, the more your performance will suffer.

As an example, let’s say that you’ve woken up at 6am after only 5 hours of sleep.

You then go to work for the day, barely able to keep your eyes open or concentrate on anything, and then you decide to go to the gym at 5.30pm.

Your tired state is simply going to be much worse later in the day, so it’s unlikely you’ll perform anywhere near the required levels.

However, getting that workout in as early as possible on a sleep deprived day will generally mean a better workout.

Plus, it could also help your day go a little better, as you’ll be on that “exercise high” for a few hours afterwards.

Something else you can do is to ingest caffeine, whether it’s a shot of espresso or a pre-workout drink, which should help you power through your workout more effectively.

2. Are You Drinking Enough Water?

Your hydration levels will have a massive impact on how strong you feel in the gym.

In fact, the Journal of Strength & Conditioning Research conducted a study in 2015.

They took participants in both a hydrated and slightly dehydrated state and measured their one-rep max for bench press.

The average one-rep max for participants who were hydrated was 118kg.

However, when the participants were tested at a later time while in a slightly dehydrated state their one-rep max bench press had decreased to 111kg.

Interestingly, the group were then rehydrated, allowed a couple of hours rest, and tested again.

This time they managed to hit an average one-rep max weight of 117kg.

So, in effect, once they were rehydrated their strength levels had pretty much returned to normal.

How much water you should drink per day can be a contentious point.

However, a good standard to aim for is one gallon of water for men, and three-quarters of a gallon for women.

This is based on the “US liquid gallon” and is approximately 3.8 litres for men and 2.9 litres for women.

Obviously, this can differ based on your activity levels.

Something that you should try to do is to drink 1 litre of water prior to your workout and another litre immediately following.

In effect, you will have consumed the majority of your water intake around your workout.

3. What’s Your Nutrition Like?

I guess it’s fairly obvious that what, when, and how you eat can have an impact on your strength in the gym.

Basically, if you haven’t eaten enough, especially carbs, it’s likely your workout will suffer.

This is due to a lack of glycogen in your muscles.

The Journal of Strength & Conditioning Research conducted another study on this very matter in 1999.

They took one female and five male participants and had them complete barbell back squats.

Initially, they performed squats with a regular carb intake.

On average, they completed 18 reps in the first set, and 12 reps in the second set.

However, subjects then had their carb intake restricted for two days prior to testing.

The average squat for the carb-depleted participants was now 13.5 reps in the first set and 10 reps in the second set.

So, as you can see, nutrition, and especially your carb intake, can have an effect on strength in the gym.

It’s advisable to always eat before you train, while ensuring you get some carbs in order to keep glycogen levels in your muscles topped up.

However, if you generally train fasted first thing in the morning then I’d advise that your evening meal the night before is quite big with a good amount of carbohydrates.

4. How Hard Are You Training?

Something else to consider is how hard you’re training.

Now, I don’t want to start talking about overtraining, as this is actually quite difficult for most of us to achieve.

However, that doesn’t mean that you may be training more than your physical capabilities allow.

Plus, going back to nutrition once more, if you are training a lot and your food isn’t on-point, you’re going to struggle with strength in the gym.

To be honest, you’re the only person that can decide if you’re training a bit too much.

Nevertheless, if you find that your performance is steadily declining in the gym then it may be time to back off somewhat.

Remember that your muscles only grow bigger and stronger if they are allowed adequate recovery time.

Furthermore, I generally like to take a complete week off from the gym every 10-12 weeks.

This allows my body to completely recover and reset.

Plus, I typically find that I come back to the gym far more motivated, and even slightly stronger.

What Too Much Exercise Does to Your Body and Brain

5. Do You Train at Different Times of the Day?

The time of day you train can also impact on how strong or weak you feel in the gym.

Firstly, your body temperature is higher in the afternoon and early evening than it is in the morning.

And there is research which suggests that strength, power, and flexibility output is much better when the body temperature is higher.

Okay, this doesn’t mean that you have to completely switch your workout routine and start training in the afternoon.

However, this is definitely something you should keep in mind.

So, if you find that your workouts don’t seem to be going particularly well first thing in the morning, try a couple of afternoon or evening workouts to see if it makes a difference.

With that being said, muscle-growth isn’t generally impacted by body temperature, but strength definitely can be.

So, armed with this information you could chop-and-change when you perform certain workouts.

Therefore, your cardio, conditioning, or hypertrophy-based workouts can be done in the morning.

Whereas, if you want to train for pure strength then aim to workout slightly later in the day.

6. What’s Your Mood Like?

The final reason you may feel weak in the gym some days is because of your overall mood.

The human mind has a funny way of being able to control us, our emotions, and even how we sometimes look at the same situation differently.

There could be days when you literally force yourself into the gym, but you’re really not in the mood to workout.

I guess there are two schools of thought here – either just power through the workout or take a day’s rest, and then come back tomorrow refreshed and reinvigorated.

Additionally, stress can be a massive strength killer.

In fact, depending on the type of workout you’re performing, and how long you’re going for, you could be increasing your levels of cortisol.

Cortisol, otherwise known as the stress hormone, is generally released into the body during the latter stages of a long workout.

If you’re doing a particularly intense workout then your glycogen stores are likely to be depleted after around 45 minutes.

So, if you continue working out after this point, the body is effectively getting more stressed.

When performing a moderate-intensity workout your glycogen stores may last for up to 2-3 hours.

With that being said, there are of course many things in life that can cause stress.

So, if there’s something that causes you pain, anguish, anger, or heartbreak it will probably have an impact on your workout.

Do Emotions Affect Your Workout?

Final Thoughts

So, as you can see, there’s a wide variety of reasons why you feel weak in the gym some days.

The most obvious places to initially look are at your eating and sleeping habits, as well as ensuring that you’re well hydrated.

Then again, how hard you’re training or even the time of day you workout can affect your strength output.

Finally, don’t forget what a powerful thing the human mind is, so your mood and emotions can definitely make you feel weaker in the gym.

I’d like to introduce you to one of my favourite workouts ever. Fitness entrepreneur and bodybuilder, Frank Rich, has created a workout program aimed at packing on muscle while keeping body fat to a minimum. You can see exactly what I thought of Frank’s workout program in my Massthetic Muscle Review.

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