Obviously nobody can diagnose injuries based on Lemmy comments. My advice is to find a good physical therapist. I found one who specializes in my sport (powerlifting) and he fixed a nagging injury I’d had for years.

Hot packs might help discomfort but they won’t help heal anything. Warming up is certainly important. Stretching could be important but the hard part is figuring out what you specifically need to stretch, which is where a physical therapist can help.

I’m running, doing core and arm workouts and eating well, and losing weight - but I can’t seem to shift the belly fat.

Just to be unambiguous, the only thing really affecting your amount of belly fat is the amount of fat you lose. You can’t spot reduce fat by doing core workouts. It’s good for general health and fitness to work out, but training abs won’t decrease belly fat at all - you need the calorie deficit for that (which you apparently do have, so that’s good, and you should work out to make sure you don’t lose 80% muscle weight but mostly fat).

Where you lose fat just depends on genetics. For me belly fat is some of the last fat to go when losing weight and some of the first to come back when gaining - results really tend to come in at the end of a cut.

dropped 4 kg, and gone from a 34 to a tight 32 on my pants (trousers)

Sounds like there’s progress. If you want more, continue.

In general, lower belly fat is the most stubborn of all – it’s usually both the last to go and the hardest to lose during diet/exercise. Like others have said, it’s going to take time and consistency, paying close attention to a caloric deficit. With that said, calorie deficits get trickier the more fat you lose and there are two things to keep in mind:

1. The more weight you lose, the less calories your body needs to function. Because of this, the gap between your maintenance calories and your caloric deficit will start to shrink. As such, you will still lose weight maintaining the same deficit but the loss will be much slower.

As you get further and further into it you might need to recalculate your maintenance calories for your new, lower weight. At that time, you might need to lower your caloric deficit number even further, but it gets harder to do once you start creeping closer to an unhealthy deficit that deprives the body of what it needs to keep organs functioning and healthy so don’t feel like going lower will always be the answer. Sometimes you just have to deal with the slower loss per week, other times you might find yourself dealing with the second thing to keep in mind.

2. As you lose more and more weight, your body will start to get more and more efficient at running off of your caloric deficit. While it’s common for a lot of us to stall for a bit at a certain point and then slowly crawl toward our body fat goals, sometimes it finally hits a level where it needs a jump start.

Some confuse this with “starvation mode” where your body thinks it’s not getting enough calories and will desperately hang onto body fat to extend survival during a deficit instead of losing it. However, this is extremely unlikely as someone would essentially have to actually be dangerously starving to activate this survival mechanism.

What actually can happen instead is that your body just gets really efficient at running off of a deficit and therefore doesn’t feel it needs to tap into the fat to perform as you are. If this does happen, you can try a calorie zigzag (also known as calorie cycling). This only works if you are strength training (resistance training with weights or bands, etc.) two or three days a week. On the two or three days you do resistance strength training, eat just a little bit more than your maintenance calories. Then, on your rest days, cardio days, yoga days, whatever days you’re not strength training, you go back to your caloric deficit.

This essentially tells your body on strength training days to use that slight caloric surplus to rebuild those muscles you just broke down during your workout, signaling you need these extra calories for a muscle bulk cycle. Then, on the other days, when you go back to your original caloric deficit, it “tricks” your body into tapping back into the stored fat for the extra calories that it was just told it needs to rebuild your muscles. So while it seems odd, sometimes you need to take two to three days a week on a slight surplus (I strength train three days a week so I do a slight surplus on my two toughest days and then maintenance calories for the other day) and then drop back down to a caloric deficit below your maintenance calories for the other four to five days in the week.

I wouldn’t think you’d need to do this just yet, but it’s something to keep in mind. It sounds like you are just approaching point #1 where the fat loss slowdown begins and just takes more time. Be patient here but also be mindful and carefully evaluate when you need to change things up so you don’t spin your wheels without going anywhere at that point.

Note: Also make sure you are getting enough protein and essential amino acids to maintain/build your muscles during your caloric deficit. As muscle building tends to require a caloric surplus, having the right amount of protein and doing strength training will tell your body that it needs to still maintain/build your muscles during a caloric deficit. This way you make sure your weight loss is consistently fat loss and not muscle loss. If you don’t do this, your body might break down muscle even further to use the amino acids it gets from doing so in order to send them to the vital organs to function and survive. And of course, it would be using broken down muscle weight instead of solely tapping into the fat you want to lose, thereby making fat loss that much slower!

When we’re at our biggest, our skin holds everything “up.” When there’s less everything to hold, our skin sags lower due to gravity and our fat hangs a bit lower. This is why the spare tire “collects” around the lower part of the abdomen when everything used to hang higher when we were at our biggest weight.

You probably have lost some girth there in the middle. Try your non-stretchy pants that you used to wear for formal occasions and see if they fit any differently now that you have lost 4 kg. Or, an old leather belt with well-worn belt holes can show progress because we’re suddenly needing the next smallest hole to hold our pants up.

I don’t know a lot about running but that sounds a lot like majoring in the minors. When you get to be an elite level runner maybe worry about things like that but until then I’d just run when it works for you. Your muscles will be fine, although I do know some runners who do a little strength training which you can consider.

Running shoes can definitely be the problem. It’s a layer of squishy-ness between you and the ground, which counteracts the taut-ness your body will get from good form. There are tons of options for shoes that have solid, non-squishy soles, but I prefer to just go barefoot.

I would try getting up and walking around every 15 minutes or so if you can. If that doesn’t work or you can’t, I’d see a doctor or physical therapist. Diagnosing pain from a comment on the Internet is a recipe for a bad time.