Why Am I Exercising & Not Losing Weight?

Hamster on wheel

Are you having trouble losing weight even though you’re exercising regularly? It may come as a surprise, but it’s a fairly common issue. People usually fall into two groups:

  1. Too much cardio, not enough intensity.
  2. Too much intensity, not enough recovery.


This is probably the most common pitfall when people are exercising for weight loss. Many people know aerobic zone exercises – jogging, elliptical, cycling and brisk walking are good for fat burning. What they might not know is that longer cardio sessions are less effective for weight loss than shorter workouts with intense, anaerobic bursts i.e. sprinting, explosive movements and weight lifting. This kind of training is called concurrent training or high-intensity interval training (HIIT) and has been shown to burn more calories during and after a workout than aerobics alone. It also suppresses appetite, where lower intensity exercise tends to stimulate appetite.

If you are doing 45 minutes or more cardio on a regular basis and not reaching your goal weight, I recommend adding high-intensity intervals to whatever cardio you’re doing. The idea is a 30-90 second high-intensity interval followed by a low-intensity interval that lasts twice as long. You can start with 4-5 repetitions and work up to as many as 25-30 minutes of intervals at a time. I find people don’t need more than 3 sessions of HIIT weekly to have a significant impact on their weight. This doesn’t mean it’s okay to be a couch potato the rest of the time. Active rest is a great place for more moderate, fat-burning exercise like yoga, brisk walking, biking to work or hiking with your family, but you don’t necessarily have to try to get an hour of cardio every day to lose weight.


On the other hand, too much prolonged high-intensity exercise can also be a barrier to weight loss. When you exercise too long, too hard, too often, you start burning muscle and negatively impacting cortisol and even thyroid levels. Cortisol is a hormone that is released during stress and exercise. At healthy levels, cortisol increases blood sugar to keep muscles supplied with fuel and activates our nervous system to give us energy. At chronically elevated levels, it contributes to anxiety, insomnia, inflammation and increased belly fat.

You probably have high cortisol if:

  • You feel stressed or anxious a lot of the time
  • Can’t sleep because your mind won’t shut off
  • Need coffee to function
  • Experience strong sugar or carb cravings
  • Your energy drops in the afternoon after lunch
  • You have a spare tire or excess belly fat

If you have one or more of the above symptoms, you are someone that would benefit from switching 1-2 prolonged high-intensity sessions for walking or yoga to reduce stress hormones and belly fat. If you are addicted to CrossFit and spinning multiple times weekly, restricting calories and not taking active rest days, this could make all the difference in your weight loss goals.

Adequate nutrition is also essential for recovery. If you are reducing calories to lose weight, you still need to make sure you have adequate carbohydrates and protein for muscle recovery. According to Peggy Walton, fitness and BodyPump instructor at Fitness SF in San Francisco, “Generally a weight training session such as BodyPump relies exclusively on blood sugar for energy. When your overall energy starts to go, it's because the body has to keep sending sugar to the brain and can't tap into its energy stores (liver, muscles, and lastly body fat) until you stop lifting the weights. I recommend a smallish amount of a quickly digestible carb (love my bananas) to signal the brain that sugar is coming, along with a low glycemic carbohydrate to keep the engine running and protein for muscle repair.” If your body doesn’t get the right nutrients, your muscles will have a harder time recovering, and it will be more challenging to reach your weight loss goals.

Post-workout snack ideas

  • Greek yogurt with berries
  • Banana with almond butter
  • Smoothie with whey or pea protein powder, dark leafy greens and blueberries
  • Smoked salmon and fresh vegetables
  • Quinoa salad with tomato and cucumber

Need more information about nutrition, exercise and hormones for your weight loss goals? Dr. Claire Graser supports patients with comprehensive, individualized functional medicine plans at San Francisco Natural Medicine. Call 415-643-6600 for a free 15-minute consult!