Your body adapts quickly and your body's fast adaptation to change is the reason you have to change your workouts more often.
Change up your routine by doing drop sets, supersets, negatives and slow reps are all classic examples. Other ways you can increase the intensity of your workout are decreased rest times, circuits, forced reps etc. When you’ve been using the same routine for a while it’s easy to get stuck in a rut, you think you’re training hard but your intensity level has been dropping slowly without you knowing it.
Change the order of your exercises
If you were doing cardio first before weight training switch to cardio after weight training. Your body will adapt to your normal routine so change it up. Switch up your exercises.
Change the number of days you train
Build more muscles: In muscle building, less is more. If you want to get bigger you don’t workout more. This is one of the most common mistakes of new lifters. Dropping back to 3 days from 4 or 5 will mean you build more muscle. Your body can really benefit from the extra rest.
Slimming down: Try different workouts for 5 days a week. Push yourself to your real limit. Try new classes at the gym that take you out of your comfort zone. Run, walk, jump, swim, plates, yoga, kickboxing, are just a few things that you can try.
You’re under too much stress
The stress response system is subconscious; it responds to stimuli and nothing else. Emotional stress, physical stress, financial stress, relationship stress – I hesitate to even make these distinctions, because the body does not differentiate between sources of stress. They all cause the body to produce cortisol, the fight-or-flight hormone that catabolizes muscle, worsens insulin resistance, and promotes the storage of fat. For 200,000 years, stress meant a life or death situation. It was intense and infrequent, and the cortisol release was arresting and extreme enough to improve the chances of survival. Today, our body responds to a stack of paperwork the same way. Traffic jams are like rival war bands. A nagging boss is like a rampaging mastodon, only on a daily basis. Take a step back from your life and take stock of your stress levels – they may be holding you back.
You need to watch your carb intake.
Carbs are key, as always, especially when you’ve got weight to lose. Veer closer to the bottom of the curve, taking care to avoid all processed food (hidden sugars). You might also try skipping fruit.
You’re eating too much.
Low-carb isn’t magic. It reins in wild hunger and tames insulin, but calories do still matter – especially once you approach your ideal weight. In fact, those last few pounds often don’t respond to the same stuff that worked so well to get you to this point. Eating nut butter by the spoonful and hunks of cheese without regard for caloric content may have gotten you this far, but you’ve got to tighten things up if things aren’t working. And that’s the real test, isn’t it? There is a metabolic advantage to eating according to the PB, but if the weight isn’t coming off, something’s up – and calories may need to come down.
You’re not getting enough sleep.
Chronic levels of sleep deprivation cause the release of cortisol, our old fat-storing friend. The biggest spike in (fat-burning, anabolic) growth hormone plasma levels occurs in deep sleep. And a recent sleep study showed that truncated sleep patterns are linked to weight gain. Get seven to eight hours of sleep a night.
You’re eating too much dairy.
Some people just react poorly to dairy. We see this time and time again listed in the forums; dairy just seems to cause major stalls in fat loss for a good number of folks. There are a couple speculative reasons for this. One, folks coming from a strict paleo background may not be acclimated to the more relaxed Primal stance on dairy. Reintroducing any food into the diet after a period of restriction can have unintended consequences on body composition. Two, dairy is insulinogenic, which is why it’s a popular post-workout refueling tool for athletes. Does a non-strength training PBer need to drink a few glasses of milk every day? Probably (definitely) not.
The best way to manage weight gain from hypothyroidism is to control the condition. If you get your metabolism back up to speed, the weight shouldn't keep adding up. You'll also have more energy, which can help motivate you to exercise.