Alex,
its funny that you and i are working on energy/excerising.. I am on GNC protein powder.. since August 10th..
well.. when i got new puppy last August 7th, she is very active.. so she helped me alot to get out of here and go for walk.. I mean LONG fast walk.. mornings and evenings... Dang, i was sore stiff and overdo :-/ .. after hard confiendce walks for 3 days.. I am still in moviation and want keep on going but my energy drain me.. so I went to GNC.. ask some questions before I purchase because of health reasons.. found out it cuts down chorestrol, burn fats, reboost energy too.. will less crave.. so I went for it.. of course first few days, my tummy went gases.. and runs (flush out the system).. last night and today, alot less gases and bubbles in my tummy.. feel great and my energy still on run... so.. I lost 9 pounds already since Aug 7 till now.. :fruit: my goal to lose 100... I am not in rush but.. just want stick with daily walks...
whats more.. Rocky and Molly behave alot better and less restless.. 
so Alex.. go for it.. unless it fits your health needs.. Good Luck ! 