C
Clarity News Hub

Why have I put on weight since running?

Author

Mia Kelly

Published Jan 13, 2026

A new exercise regimen puts stress on your muscle fibers. This causes small micro tears, also known as micro trauma, and some inflammation. Those two conditions in your muscle fibers are the reason you may gain some weight.

Why am I gaining weight when I started running?

It's not uncommon to gain a few kilos when you start ramping up your runs, like when you're training for your first marathon. Your muscles respond to the elevated effort level by storing more glycogen, which binds with water in your muscle cells to keep you fueled and can tick the scale up by one or two kilos.

Is it normal to gain weight from running?

You're Gaining Muscle

When you ask, Can you gain weight from running? the answer is yes. But that's not always a bad thing. If you're doing a lot of HIIT-style run workouts like hill running, or additional strength strengthening, you will be building muscle alongside the cardio you get from running.

Why have I gained 10 pounds since working out?

“When you start exercising, your muscles start gobbling up fuel called glycogen,” says Krista Scott-Dixon, Ph. D., Director, Headspace Adjustment Bureau, Precision Nutrition. Since glycogen stores water, you could gain up to 10 pounds in water weight alone, says Scott-Dixon.

Why am I gaining weight instead of losing while working out?

Muscle mass is denser than fat mass and you will undoubtedly gain weight from lean muscle gains. While your clothes may feel looser, the scale may tell you otherwise. This is a win! You're working a well-rounded program that includes both strength and conditioning and now you're reaping the reward.

41 related questions found

What is runners belly?

Runner's stomach occurs when our digestive system experience a large amount of agitation from the act of running or high-endurance exercise.

Is it normal to gain weight before losing?

You'd think that going on a strict diet and exercise regimen would help you drop pounds quickly, but most people actually gain weight at first. If this has happened to you, don't give up on your goals just yet.

How many times a week should I run to lose weight?

Burning Calories

If your goal is to lose weight generally, you should run about 3 or 4 times a week on alternating days for about 45 minutes. On rest days it is still crucial to engage in some form of exercise. Moving and burning calories are key! Most people overestimate the calories they burn on a run.

Will running reduce belly fat?

Studies have found that moderate-to-high aerobic exercise like running can reduce belly fat, even without changing your diet ( 12 , 13 , 14 ). An analysis of 15 studies and 852 participants found that aerobic exercise reduced belly fat without any change in diet.

How long until you start losing weight from running?

Significant weight loss and muscle gains will take approximately eight weeks to see, however, even though you're not seeing muscle definition, the benefits going on in your body and mind are considerable.

How long does it take to see results from running?

If you're just starting a new running routine and were previously inactive, you can see improvements in your cardiorespiratory fitness within four to six weeks. If you've been running for a while and you're trying to get faster, it may be a few months before you see any noticeable gains.

Why do I keep gaining weight even though I exercise and eat right?

You're Eating Right -- but Getting Too Much Sodium

Sodium dissolves in your body fluids, and the more sodium you eat, the more your body will retain water to maintain a healthy sodium balance. That means eating salty fare can add a few pounds to your weight on the scale, seemingly overnight.

Why can't I lose weight when I exercise and eat right?

One of the main reasons why burning calories through exercise may still not result in weight loss is due to overexertion, or inflammation of your body. If you exercise too hard on a daily basis, there is an excess of inflammation in your body. All the added up inflammation makes you gain more weight than lose.

How long does it take to see results from working out 5 days a week?

You're putting your whole heart and soul into the fitness regimen, going to the gym five days each week. You should be able to notice visible changes after about two weeks of training 5 days a week.

Does running tone your arms?

As running causes fat burning in the entire body, your arms will also get slimmer with time. However you cannot spot reduce the fat in your arms. If you swing your arms while running, you can help more fat burning and toning of arms and shoulders.

Does running give abs?

Helps to Build Core Strength

And for runners who don't have time to hop on a treadmill or to head outside for a run, simply running in place while activating your core muscles can be effective for strengthening all of your postural muscles, including the abs, according to studies.

Why am I getting worse at running?

Assuming you are in good health, the most likely culprits are overtraining syndrome or inadequate energy availability. However, it might be wise for you to be checked by your physician to make sure that you do not have blood, thyroid, heart or other health issues as the root cause of your change in performance.

Will I lose weight exercising 5 days a week?

Kabir Khan, fitness trainer and instructor at The Studio, Mumbai, agrees and adds that "five days a week of exercise doesn't automatically ensure weight loss." Khan says the type and intensity of exercise a person is doing will significantly impact weight.

How many days a week should you exercise to lose weight?

How much weight you lose depends on the amount of exercise you're willing to commit to and how closely you stick to your diet. If you really want to see results reflected on the scale and continue to make progress over time, you need to commit to working out at least four to five days per week.

Why have I stopped losing weight in 2weeks?

Unless your weight has been stuck at the same point for more than 1–2 weeks, you probably don't need to worry about anything. A weight loss plateau may be explained by muscle gain, undigested food, and fluctuations in body water. If the scale doesn't budge, you might still be losing fat.

Can too much cardio cause weight gain?

According to Noah Abbott, a CrossFit coach in Brooklyn, prolonged, steady-rate cardio can deplete our body's Triiodothyronine, or T3 hormone. This hormone is responsible for metabolism, and a depletion of this hormone can cause the body to go into a mode where it stores and gains more fat than usual.

Why can't I lose my stomach weight?

Unhealthy eating is the biggest driver of big bellies. Too many starchy carbohydrates and bad fats are a recipe for that midsection to expand. Instead, get plenty of veggies, choose lean proteins, and stay away from fats from red meats. Choose healthier fats in things like fish, nuts, and avocados.

Can too much exercise cause weight gain?

Weight gain

Exercising too much without resting enough in between can lead to low testosterone levels and high levels of cortisol, the stress hormone. These hormonal changes are often associated with loss of muscle tissue, weight gain, and excess belly fat.

What happens if you run everyday for a month?

Running every day may increase your risk for an overuse injury. Overuse injuries result from taking on too much physical activity, too fast, and not allowing the body to adjust. Or they can result from technique errors, such as running with poor form and overloading certain muscles.

What happens to your body when you start running everyday?

Your muscles have strengthened, keeping your metabolism boosted and your weight easy to maintain. Some studies also show that running over many years can reduce your risk of certain cancers and keep your mind and memory sharp. You have probably even lengthened your lifespan.