@<b><u><a href="http://www.pakgamers.com/forums/members/mac007/" target="_blank">mac007</a></u></b> I don't have extensive headphones experience but what I have used I can recommend from that
Sennheiser HD598 Closedbacks ... Really love them, usually retail at 120-150 but they were selling for as less as $99 in last week, easy to drive, MacBook iPhone n HTC M9 make them scream easily and I'm sure with a decent amp like FIIO E10k they would sing better (just 23ohms) but I'm not sure if they will be useful during workouts
I also have Marshall Monitor I think they have just beautiful sound, love EQs and the lows, they have just better lows than 598s. Last night I was listening to a few songs of A perfect circle and felt some mid lows which 598s couldn't deliver. Costs just around $100 and build quality is top notch, clamping force is decent and for normal ear size person they r over ears and will definitely be good during workouts as they r not easy to shake-off ur head
Sennheiser Urban XL can also be a choice
I would recommend any wireless solution like Momentum 2 or Bose soundtrue or QC25 (If QC35 is too expensive) cause wired headlines will be difficult to manage
Vmoda crossfade wireless can also be a good option but $250+
If ur friend has decent budget ask him to try if he can buy these planner magnetics ... Monoprice M560, they have amazing build quality and one of the best features is they can be open backs or closed backs ... And cost just $199 at the moment but will increase ... If I had not purchased HE400i I would have gone for these ...
Easy to drive and sound well plannars can do anything, but for workouts ... Hmm not so many reviews out yet but they have not that strong clamping force ...
Check this video as well
Monoprice M560 - Review - YouTube
[video]https://www.youtube.com/shared?ci=ffwBydKxesg[/video]