Hi Soberish,
I definitely find it gives me a boost altho its only been the last few days where I have started to feel really good after a workout, (33 days now) first couple of weeks were extremely difficult with little / no energy but pushing myself through.
Cardio isn't really my thing for long - steady state I just find boring but do enjoy HIIT on some cardio machines and get a great boost from it, have a few niggling injuries that I have to be careful with one being a herniated disc which means running, something I enjoyed for a while is a no go and I also need to be careful lifting, especially leg workouts.
Nowadays I'm trying not to over do it, as with anything I do it seems to get to the point of obsession - eating plans etc - trying to relax myself but not the easiest - drive the wife nuts with things - however I've switched my obsession at present to not drinking or doing drugs - glad to say that's working tho !!
Anyway back to training - why not try and swap it about a bit, cardio can become boring and you really don't need to be in there for hours on the treadmill to reap the benefits.
My routine at present which I have adjusted to try to ensure injury free has reverted back to machines mainly rather than free weights but it's working for me - 6 to 10 min warm up on the cross trainer then stretching. Then 3 sets of 10 - 12 reps on various machines - all upper body plus some ab work (leg raises / planks at the end) and then to finish off Tabata on the bike - gruelling but it gives you such a boost - basically warm up for 1 min then 8 sets of 20 secs giving it as much as you physically can and 10 secs rest - 5 mins in total but boy do you know you've done it - head spinning and feeling quite sick if you've done it properly - especially the first couple of times.
There was a documentary on about it a while ago here in the UK regarding the Tabata workouts and that the 5 min is enough daily - doesn't feel like that would be enough for me but you know you've done it.
I then throw in a 1 or 2 days on the recumbent bike doing HIIT but on high levels of resistance to try and work the legs a bit - found I am staying injury free this way and not getting any back problems.
Other thing I was doing recently was a lot of bodyweight work again HIIT but oh does it blast the body fat (along with a good diet) and gives you massive energy boosts.
A really good diet is key too I find - eat 5 -6 meals a day (cut sugars / all processed foods) only proteins and veg (no root or fruit / dairy) for 2 weeks, it's tough but works then re-introduce fruits and other complex carbs slowly over the next few weeks) - Oh and the biggest one no alcohol - but we've got that one covered ;-)
I'm not going as obsessive as usual about it at present but when completely clean and the sugar & rubbish is omitted from the diet the boost is huge and your general wellbeing and feeling is hard to describe how good it is. I definitely do see sugar as a problem for moods and general fatigue - cut it and out and it improves so much - however its also enjoyable and I realise I have to live a little too.
5 weeks prior to my last binge that made me realise its time to stop the drink and drugs this was exactly how strict I was and to be honest I was absolutely flying.