When you're determined to meet your weight loss goals, you might think that hitting the gym hard is the fast track to your dream body.
But now an expert has revealed that too much exercise could in fact inhibit your efforts to slim down, due to the hormones that lengthy or high-intensity sessions release.
According to hormone specialist Sara Gottfried, the optimum amount of exercise to do is 20 to 30 minutes a day, four times a week, Byrdie reports.
And she says that rather than sitting in a chair all day and then hitting the gym hard for hours, it's better to do less intensive - but more regular - movement.
Try using a standing desk or incorporating short walks into your day, instead of cramming all your movement into a single, full-on workout, she says.
And when you do go for a workout, she recommends barre classes, yoga and Pilates which exercise the entire body and tone you up - without causing excess stress.
According to Dr Gottfried, intense exercise puts stress on the body which prompts the release of corticotropin-releasing hormone (CRH) and cortisol.
Balancing stress hormone levels
Dehydroepiandrosterone or DHEA is a steroid hormone made in our adrenal glands, reproductive organs and the brain.
As DHEA comes into play when minds and bodies perceive 'danger' has passed, it's associated with how well we cope with challenges.
To build up your levels, include plenty of healthy fats in your diet to create cholesterol from which we make both cortisol and DHEA.
Nuts, seeds, oily fish, avocados, free-range (preferably grass-fed) meat, organic eggs, butter and Greek yoghurt, coconut and olive oil all add up to a healthy range of the building blocks for good stress coping mechanisms and brain chemistry.
Keep sugar to the minimum and have protein for breakfast to start your day from a stable mood.
"CRH increases the permeability (or leakiness) of the intestinal wall as well as the permeability of the lungs, skin, and blood-brain barrier," she said.
Meanwhile, high cortisol levels can block digestion and hinder blood flow to the gut, which is certainly not what you want when you're trying to shed those pounds.
Professional athletes actually take supplements to combat these issues, but if you're not training for the Olympics then there's no need to do exercise that puts your body under such intense stress.
It's particularly crucial not to up your stress levels with high intensity exercise if you're already feeling under pressure in other areas of your life.
Having high levels of cortisol - dubbed the stress hormone - causes people to reach out for comfort foods, experts believe.
And those products high in fat, sugar and calories are damaging their waistlines.
While the hormone also determines where fat is stored in someone, with those stressed more likely to get flab around their stomachs.
Those classified as obese also had particularly high levels of cortisol, a study published in the journal Obesity found.
Study author Dr Sarah Jackson said: "These results provide consistent evidence that chronic stress is associated with higher levels of obesity.
"People who had higher hair cortisol levels also tended to have larger waist measurements, which is important because carrying excess fat around the abdomen is a risk factor for heart disease, diabetes, and premature death."