Calories Burned Doing sit-ups at 55 kg — 209 kcal per Hour
Doing sit-ups at 55 kg (110–132 lb) burns about 209 kcal per hour. That figure comes from the activity's MET value of 3.8 in the 2011 Compendium of Physical Activities, multiplied by body weight: 3.8 × 55 kg × 1 hour = 209 kcal. This page works the numbers out in full — for 15, 30, 45, 60 and 90 minutes, across all four weight bands, and against four comparable activities at the same weight — so you can plan sessions with real figures instead of guessing.
Sit-ups are the classic abdominal exercise: lying on your back and curling your torso up towards your knees. The Compendium's closest published value is calisthenics at a moderate effort, 3.8 METs.
They suit people adding core work to a session, though modern training usually pairs them with planks and other core exercises rather than relying on sit-ups alone. The headline number to remember is 209 kcal per hour at 55 kg, or about 104 kcal for a 30-minute session. Everything below is an estimate: MET values are population averages, and your own burn will vary with fitness, technique and conditions. That does not make the numbers useless — it makes them a planning tool, and a good one, as long as you treat them as approximate.
Calculate your own numbers
Use the Calorie calculator to work out your own burn for doing sit-ups at your exact weight and session length. Enter your weight, pick the activity and set the duration, and the tool applies the same MET formula shown below. You can also try the calorie calculator to see how this session fits into your total daily energy use.
Related pages in this section:
Calories Burned Calisthenics at a vigorous effort at 55 kg — 440 kcal per Hour
Calories Burned Doing a bodyweight workout at 65 kg — 325 kcal per Hour
Calories Burned Weight lifting at a light effort at 85 kg — 255 kcal per Hour
The formula, shown and cited
The standard way to estimate the energy cost of an activity is the MET formula from the Compendium of Physical Activities (Ainsworth et al., Medicine & Science in Sports & Exercise, 2011; 43(8): 1575–1581):
Calories (kcal) = MET × body weight (kg) × duration (hours)
One MET is the energy you use sitting quietly at rest — about 1 kcal per kilogram of body weight per hour. An activity rated at 3.8 METs therefore uses 3.8 times as much energy as resting. The Compendium's MET values come from published studies that measured oxygen use during each activity, so they are measured averages, not guesses. Where no exact Compendium entry exists for an activity, the data file uses the closest published value and says so — the value used here, 3.8, is the one recorded for doing sit-ups in the FitCalc activity data.
Worked through for this page:
- MET for doing sit-ups: 3.8
- Body weight: 55 kg (the midpoint of the 50-60 kg band, 110–132 lb)
- Duration: 1 hour
- Calculation: 3.8 × 55 × 1 = 209 kcal
For a 30-minute session the same calculation is 3.8 × 55 × 0.5 = 104 kcal. Nothing else is hidden in the maths — if your weight or duration changes, only those two numbers change.
Your numbers at 55 kg
| Duration | Calculation | Calories burned |
|---|---|---|
| 15 minutes | 3.8 × 55 × 0.25 | 52 kcal |
| 30 minutes | 3.8 × 55 × 0.5 | 104 kcal |
| 45 minutes | 3.8 × 55 × 0.75 | 157 kcal |
| 60 minutes | 3.8 × 55 × 1 | 209 kcal |
| 90 minutes | 3.8 × 55 × 1.5 | 314 kcal |
That is about 3 kcal per minute of doing sit-ups at this weight. A short session still counts: even 15 minutes burns 52 kcal, and three 15-minute sessions across a day add up to the same 157 kcal as one 45-minute session.
How the burn changes with body weight
The MET value stays the same — it describes the activity, not the person — but the calorie total scales with weight, because a heavier body costs more energy to move:
| Body weight | Calories per hour | Calories per 30 minutes |
|---|---|---|
| 55 kg | 209 kcal | 104 kcal |
| 65 kg | 247 kcal | 124 kcal |
| 75 kg | 285 kcal | 142 kcal |
| 85 kg | 323 kcal | 162 kcal |
Two people doing the same activity for the same time can therefore burn quite different amounts, and that is expected — it is physics, not a mistake in the formula. If your weight sits between two rows, your figure sits between the two values.
How doing sit-ups compares
Here is doing sit-ups against four other activities at the same 55 kg, all using the same MET formula:
| Activity | MET | Calories per hour at 55 kg |
|---|---|---|
| doing sit-ups | 3.8 | 209 kcal |
| weight lifting at a light effort | 3.0 | 165 kcal |
| doing a bodyweight workout | 5.0 | 275 kcal |
| walking briskly (4 mph) | 5.0 | 275 kcal |
| calisthenics at a vigorous effort | 8.0 | 440 kcal |
Use this table to choose, not to judge. A higher number means a harder session, not a better one: the activity you enjoy and repeat three times a week beats the activity that burns more per hour but that you quit after a fortnight. Mixing intensities across the week — one harder session, two easier ones — is usually more sustainable than doing the hardest activity every time.
Fitting doing sit-ups into your week
| Sessions per week | 30 minutes each | 60 minutes each |
|---|---|---|
| 2 sessions | 209 kcal | 418 kcal |
| 3 sessions | 314 kcal | 627 kcal |
| 5 sessions | 522 kcal | 1,045 kcal |
Ten minutes of sit-ups burns about 35 kcal at 55 kg, which shows why nobody does sit-ups for the calorie burn — the value is in core strength and control. As a rule of thumb, 150 minutes of moderate activity a week is the widely used target for adults; at 3.8 METs, doing sit-ups counts as moderate activity, so it contributes directly towards the 150-minute target. Build up gradually — add 10% to your weekly total at most, and keep at least one rest day.
How to use the result
Keep the movement controlled, exhale on the way up, and stop if your lower back hurts — a crunch or a plank is a better choice for many people. Use the numbers on this page to set realistic expectations rather than to chase a daily total. If you are tracking food as well, add the session's calories to your total daily energy expenditure for that day, and remember that the figure is an estimate with roughly 10–20% uncertainty. Do not eat back every calorie the calculator shows: activity trackers and MET estimates both tend to overstate slightly, and a small margin keeps a weight-loss plan on track. If you are aiming to lose weight, keep the deficit modest — 300–500 kcal a day is a common, sustainable range — and keep your total intake above the safety floors of 1,200 kcal a day for women and 1,500 kcal a day for men unless a healthcare professional advises otherwise.
What the number does NOT tell you
The MET formula is honest about what it measures and silent about the rest. It does not account for your fitness level: a fit person burns fewer calories doing the same activity than an unfit person, because their body is more efficient. It does not account for body composition — two people at 55 kg with different amounts of muscle and fat will burn slightly different amounts. It does not include the afterburn (excess post-exercise oxygen consumption) that follows hard sessions, it does not measure strength, flexibility or balance gained, and it says nothing about how the activity affects your appetite, sleep or mood. It also cannot tell you whether the activity is safe for you: if you have a heart condition, joint problems, asthma or any other health concern, check with a healthcare professional before starting a new, intense activity. Use the calorie figure as a planning estimate, and judge the activity by how you feel doing it and whether you keep doing it.
Frequently asked questions
How many calories do I burn doing sit-ups for 30 minutes at 55 kg?
About 104 kcal. The maths is 3.8 METs × 55 kg × 0.5 hours = 104 kcal. That is an estimate from the Compendium average — your real burn depends on your fitness, your pace and the conditions. If you weigh more or less than 55 kg, use the weight table above to read your own figure.
Is doing sit-ups good for weight loss?
It can help, but only as part of an overall calorie deficit. At 55 kg, an hour of doing sit-ups burns about 209 kcal, which is a useful contribution — roughly the energy in a modest meal — but weight loss still comes from the total balance of food and activity across the week, not from one session. Aim for a gradual loss of 0.5–1% of body weight per week, and never drop below 1,200 kcal a day (women) or 1,500 kcal a day (men) without medical supervision.
How does doing sit-ups compare with walking briskly?
At 55 kg, doing sit-ups burns about 209 kcal per hour against 275 kcal for brisk walking. If the number is higher, doing sit-ups is the more intense activity; if it is lower, brisk walking burns more. The best choice is usually the one you will actually do several times a week — consistency matters more than a small difference in the hourly rate.
Does the calorie burn change if I weigh more or less than 55 kg?
Yes, directly. Calories = MET × weight in kg × hours, so the burn scales with body weight. At 55 kg the same hour of doing sit-ups burns about 209 kcal; at 85 kg it burns about 323 kcal. The MET value itself does not change with weight — it describes the intensity of the activity.
How accurate is the 3.8 MET value for doing sit-ups?
It is a population average from the 2011 Compendium of Physical Activities (Ainsworth et al.), which compiled measured energy costs across published studies. Individuals vary by roughly 10–20% around the average because of fitness, body composition, technique and conditions. Treat 209 kcal per hour as a planning estimate, not a precise measurement of your own body.
Estimates only, not medical advice. Minimum safe intakes: 1,200 kcal/day women, 1,500 kcal/day men — consult a healthcare professional before a very-low-calorie diet.