Hello,
I am a 50 year old male, it pretty good shape (i have worked out most of my life), I have a degree in Exercise Sports Science, I am a blue belt, and I need to lose weight.
Currently I attended TKD with my daughter twice a week for 2 hours per session.
I need advice from some experienced people please. It is true I have a university degree in Exercise, but I have never been 50 before nor doing Martial arts heavily like now. It is putting unique strains on my body. Weight just is not shedding and I have read so many article and books....
So what do you suggest I do as a workout for the 2-3 days I am not in TKD? Weight training, yoga, Cardio, interval training????
Yes, I am aware diet is important and that is already changed.
Please, any advice would be great.
First and foremost, if you have not already had a good, thorough 50-year old health checkup (yes, that means going in from the top and the bottom

) get it done. Make certain there are no extenuating circumstances making things harder than they already are.
I am going to give some of my answers in the form of questions and observations of your post, so the observations are based on very limited information.
I am 58 so I fully get the 'I have never been 50 before' comment.
My experience with sports science was with my trainer when I made my Olympic run. He was very good at understanding there is no one set of metrics that work for everyone and he took the time to figure out what worked best for me. The parameters were different; we were working on S&C while maintaining weight (slight gain). But he always talked about how important it is to determine the inputs and subsequent results to know what is and is Not working. In other words, don't waste time doing things that have little or no effect. You will figure out this includes the foods you eat.
Some of my comments come from your othr posts.
You said you are doing MA's with your young daughter. Is this literal? Are you taking the same class? If so, do you truly believe you are working out at a level that nets results for your body size/type? An adult and a kid workout are two very different animals. Some schools/instructors can merge the two together and make it work for everyone, some do not.
Even though I feel two-hour classes are better, they are becoming less and less frequent. The key question is how much of each 2-hour block are you actually working out? For how long are you able to have a measurable increase in heart rate and cardio? Don't be guilty of thinking a light sweat constitutes cardio. I see this all the time.
Is your work/lifestyle sedentary? This is very important. As you know, the body is akin to a hydraulic system, including a logic controller and a power source. The greatest efficiencies in any system like this are netted when the machine operates for a long(er) time. Running in steep peaks then steep valleys leads to all kinds of problems. The same is true with the body. Going from full start to full stop gets SO much harder as we age. Jumping into an exercise program from a baseline of near zero (sedentary) is simply harder. Doable but harder. It is very important to recognize this and set expectations accordingly.
***Disclaimer*** I am not trained in exercise science and only know what I have experienced firsthand and have seen. I do know everyone's 'engine' performs differently. The system is quite complex. When someone figures out how to truly modify the logic controller to affect weight loss they will be a go-zillionaire.
What is important to reconcile is that none of this matters for you. I wonder if you are basing your personal results off your 'established' norms from you education. That dog just will not hunt.
1.) because they were partly or mostly wrong in the first place (way too broad)
2.) because you are 50. Deal with it.
Have you ever applied your education and knowledge? Actually pressure tested them? Taken it beyond the classroom? Because this is exactly where you are right now.
Create a plan around the measurables you are seeing from your current exercise work. No, I doubt they will necessarily follow what you were taught. Whether that is surprising or not does not matter. But you should have the knowledge to understand and process the known inputs to determine what is working and what information is missing. This may sound complex but it really is not.
If you are like me when I passed 50 keeping my strength has been much harder. So smart strength training with weights is a very important part of the recipe. As you can, add incremental cardio and interval training. I have very, very messed up legs and one of the best exercises I still do are bleacher runs (walks for me). They pretty much take care of everything. Balance, coordination, lower body strength, cardio conditioning, spatial conditioning, But do what you can; Yoga is great for everything I mentioned except the cardio.
All in all, I really feel you are looking at yourself and expecting your body to react like it did when you were 25. Ain't gonna happen.