What can 100 sit ups a day do?

Quick Answers

Doing 100 sit ups per day can provide several benefits if done consistently over time. Some key things 100 sit ups per day can do include:

– Strengthen and tone the abdominal muscles
– Improve posture and core stability
– Burn calories and boost metabolism
– Help reduce body fat, especially around the midsection
– Build endurance in the abdominal muscles
– Improve sports performance for certain activities

However, simply performing 100 sit ups per day alone is not enough for well-rounded core strength or fat loss. A comprehensive fitness routine that includes additional core exercises, cardiovascular training, and a healthy diet is ideal.

How Sit Ups Work Core Muscles

The sit up primarily works the abdominal muscles including:

  • Rectus abdominis – long muscle running down the front of the abdomen
  • External obliques – muscles on the sides of the abdomen
  • Internal obliques – muscles underneath the external obliques

As you raise your torso off the ground during a sit up, these muscles contract and shorten. The rectus abdominis flexes the spine to lift the torso. The internal and external obliques work together to rotate and laterally flex the spine.

Sit ups also secondarily engage the hip flexors and lower back stabilizers. However, the brunt of the exercise is borne by the rectus abdominis.

This abdominal muscle contraction needs to happen repeatedly through a full range of motion to see strength and hypertrophy gains. Thus, doing 100 reps per day can promote abdominal development over time.

Strength and Toning Benefits

Done properly and consistently, 100 sit ups per day can lead to several benefits:

Increased abdominal strength

Sit ups performed daily will gradually strengthen the abdominal muscles. As the muscles adapt to the frequent loading, they can better produce force and torque during each contraction.

Enhanced abdominal muscle tone

The repetitive flexion of the abdominals causes the muscle cells to grow larger through sarcoplasmic hypertrophy. This increases muscle size and causes the toned, firm look most people want in their midsection.

Full range of motion gains

Many people only go halfway up when doing sit ups. Doing 100 full ROM reps daily trains you to use the abdominals through their fullest potential excursion for strength across the entire motion.

Core stability improvements

When performing sit ups, the abdominals must contract isometrically to stabilize the pelvis and spine. This trains core stability that can transfer to better posture, balance, and agility.

Muscular endurance growth

Working up to 100 sit ups improves the endurance capabilities of the abdominals. Just like training for a marathon builds cardiovascular endurance, high rep training boosts muscular endurance.

So in summary, consistent 100 rep sit up workouts can create visible abdominal tone and function.

Calorie Burn and Metabolic Effects

In addition to abdominal strengthening effects, daily sit up training also boosts calorie burn, both during and after your workout:

Total Calories Burned Per Workout

* 100 sit ups in 5 sets of 20 reps = around 50 total calories burned

This assumes a 155 lb person doing sit ups at a moderate pace with brief rests between sets. The actual amount will vary based on your body size and exercise intensity.

Afterburn Effect

Abdominal exercises like sit ups create an EPOC (excess post-exercise oxygen consumption) effect. Your body uses extra energy after your workout to recover and adapt to the activity.

Doing 100 sit ups daily can lead to a higher metabolism on your workout days even hours after exercise. More calories burned makes achieving a calorie deficit easier for weight loss.

Increased Muscle Mass

Gaining lean muscle requires strength training and a calorie surplus. But the muscle boost from 100 daily sit ups can slightly raise your resting metabolism since muscle burns more calories than fat.

So calorically, 100 sit ups per day complements diet and cardio for weight management. It won’t produce major fat loss on its own, but contributes.

Fat Loss Effects in Your Midsection

Performing 100 sit ups every day directly works the abdominal muscles. But this alone will not necessarily decrease belly fat. Spot reduction has been disproven.

However, sit ups can help reduce abdominal fat through:

Building abs to reveal when body fat drops

You must lower overall body fat through diet to lose the fat covering your abs. But developing the abdominals makes them more visible at a given body fat percentage.

Creating a mild calorie deficit

The extra energy expenditure from daily sit ups as explained earlier puts your body in a slight calorie deficit if intake remains the same.

Motivating clean nutrition

Training abs can psychologically motivate people to make smarter nutrition choices to enhance fat burning and achieve an aesthetic midsection.

So in summary, 100 sit ups per day will not directly burn belly fat. But it can complement weight loss efforts to reveal toned abdominal definition.

Effects on Posture and Core Stability

The abdominal muscles play a key role in stabilizing the lumbar spine and pelvis. Strengthening them improves static posture and dynamic core stability.

Spinal stabilization

When contracted, the abdominals compress the front of the spine to maintain proper spinal curves. This combats poor posture from long periods of sitting and slouching.

Pelvic tilt correction

Overly tight hip flexors can tilt the pelvis forward, causing lower back arching. Stronger abs help posteriorly tilt the pelvis to correct this.

Balance and stability

The constant isometric contractions during sit ups improve core stability for better balance during mobility and sports performance.

So in short, developing abdominal strength through daily sit up training fosters superior static and dynamic posture.

Improving Sports Performance

A strong and stable core is vital for optimal performance in many sports and activities.

Here’s how daily sit up training can translate to better performance:

More powerful punches

For combat athletes, stronger abdominal contractions can transfer more force to the upper body for more powerful punches.

Increased running efficiency

Better spinal stability keeps the back aligned and engaged during runs, improving running economy.

Enhanced sports posture

Proper posture helps athletes master proper technique and movement mechanics in their sport.

Better lifting form

Weightlifters can brace their core harder during lifts like squats and deadlifts to lift heavier weights with a neutral spine.

Faster swing speeds

Force generated by the abdominals can contribute to faster swing speeds in baseball, golf, hockey, and other sports.

So daily sit up training forms a strong athletic core for transmitting power, proper technique, and maximizing safety and performance.

Optimal Sit Up Technique

To receive the full benefits of daily sit up training, utilize proper technique:

Lay flat on your back

Start lying down with your back flush on the floor, knees bent, and feet flat. You can place your feet under something for anchorage.

Hands behind or across your head

Place your hands lightly behind or across your head without pulling on your neck. Avoid crossing arms across your chest.

Initiate with your abs

Lead the motion with your abdominals contracting instead of passively swinging up using momentum.

Raise your back off the floor

In a controlled motion, raise your entire upper back off the floor, keeping your low back pressed down throughout.

Full range of motion

Reach the fully upright position before slowly lowering back down until your shoulder blades touch the floor to complete one rep.

For variation, twist slightly side-to-side to engage your obliques. But always move through a full range of motion while keeping proper spinal alignment.

Common Sit Up Mistakes

Take care to avoid these common sit up errors:

Partial range of motion

Only going halfway up works the abdominals through a partial ROM, failing to train full muscular development.

Pulling on the head and neck

Hands should rest lightly on either side of the head without pulling for proper head alignment.

Arched lower back

Overarching from using hip flexors creates risk for vertebral hyperextension and low back injury.

No full shoulder blade return

Failing to lower fully back down shortens range of motion and muscular activation.

Bouncing off the floor

Excessive momentum turns the exercise into an ineffective waist wiggle that yields minimal benefits.

By performing sit ups with deliberate technique and full range of motion, you’ll safely maximize abdominal activation.

Complementary Exercises

While beneficial, 100 sit ups per day should not be your sole abdominal exercise. Complement sit ups with additional core-focused exercises:


Planks excel at training core stability through constant isometric contractions with little to no movement.

Leg raises

Leg raises target the abdominals dynamically while also increasing flexibility through full hip flexion.


Crunches enable higher rep sets due to their limited range of motion compared to full sit ups.

Russian twists

Russian twists are an effective rotational exercise to train the obliques for a toned waistline.

Hanging knee raises

Hanging variations like knee and leg raises challenge core stability since you can’t use your lower body for compensation.

Aim for 2-4 sets of 10-15 reps of 2-3 different core exercises 1-3 days per week for balanced abdominal strength.

Nutrition for Visible Abs

Without proper nutrition, performing even 100 daily sit ups will not reveal visible six pack abdominal muscles. Follow these diet tips:

Maintain an overall caloric deficit

You must burn more calories than you consume consistently to reduce overall body fat.

Prioritize protein intake

A high protein diet preserves lean mass when cutting and supports muscle growth from training. Shoot for 0.5-1 gram per pound of body weight.

Reduce refined carbs and sugar

Lowering refined carbohydrates and sugars will decrease calories and lower visceral abdominal fat storage.

Up your fiber intake

Eating more fiber from vegetables, fruits, and whole grains helps regulate appetite and digestion for better body composition.

Stay hydrated

Proper water intake aids digestion, boosts metabolism, and prevents bloating for better visible abs. Aim for 3-4 liters per day.

No single exercise can reveal six pack abs. But combined with proper nutrition, 100 sit ups per day can effectively target abdominal muscles as part of a comprehensive fitness regimen.

Possible Drawbacks of 100 Sit Ups Per Day

Despite the potential benefits, exclusively doing 100 sit ups daily long-term may cause issues for some:

Risk of overuse injuries

High repetition of a single exercise pattern can potentially irritate lower back or abdominal tissues through overuse.

Limits muscular diversity

100 reps leaves less time for working other body parts. Balance with other exercises for well-rounded fitness.

Reduced results over time

As your body adapts, 100 sit ups may provide diminished strength and hypertrophy gains compared to varying your training.

Time commitment

Workouts with only one exercise can become boring and unsustainable. Most benefit from varied, time-efficient total body training.

Lack of cardiovascular training

Sit ups provide negligible cardiovascular benefit. You still need additional cardio for optimal heart health and fat loss.

Should You Do 100 Sit Ups Per Day?

Here are some general recommendations on performing 100 sit ups daily:

Try it short term

Commit to 100 daily sit ups for 2-4 weeks. Assess your abdominal progress and how you feel.

Use it to establish a habit

The frequent training can help make core work a daily habit even if you don’t stick with 100 reps long-term.

Split up the volume

Break up 100 reps into smaller sets spread throughout the day for easier recovery.

Vary your training

Periodize sit ups by cycling lower and higher rep ranges and alternating other ab exercises.

Listen to your body

If you experience pain, soreness, or burnout, reduce volume and frequency.

While 100 sit ups per day can be effective, integrate it strategically into a balanced and sustainable exercise plan.

General Abdominal Exercise Guidelines

Here are research-backed recommendations for safe and effective abdominal training:

Train abs 2-3 days per week

Allow at least a day of rest between ab workouts for proper recovery and adaptation.

Use a controlled range of motion

Safely move through a full range of motion using your abdominals instead of momentum.

Include variety

Perform a mix of crunches, planks, leg raises, twists, and focused exercises like sit ups.

Maintain proper form

Bracing your core and maintaining spinal alignment optimizes results and prevents injury.

Utilize high reps

Aim for relatively high rep ranges like 12-20 for muscular endurance. But vary rep schemes.

Add weight progressively

When bodyweight becomes easy, add resistance progressively with small 5-10 lbs plates or dumbbells to increase intensity.

Monitor for overtraining

Watch for excessive soreness, consistently declining performance, and lack of progress.

Following these evidence-based guidelines will build a strong, functional core and sculpted midsection using sit ups and a variety of ab exercises.


Performing 100 sit ups every day can strengthen and tone the abdominal muscles, enhance sports performance, and compliment nutrition and cardio for fat loss over time. Make sure to use proper technique and combine sit ups with other core-focused exercises for balance. Done strategically, 100 daily sit ups can be an effective tool as part of comprehensive fitness programming. Just be sure to listen to your body and adjust as needed based on your specific fitness goals.

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