"Hey Vic, I left my towel at home. Help me out."

Comparing one's progress to that of the others at a new gym was a very easy pitfall to fall into. Especially when you first walked in the door and saw everyone else at work.
Jaeger was really feeling that particular struggle at PFP (Push For Perfection). But he was going to power through those nerves. This was the best option he had for working out. It was the nearest gym to him, the first class was free, and he wasn't picky. From the website's sharp, stark, black-and-red design, he knew the place was going to be a bit full on.

He definitely wasn't expecting everyone around him to be twice his size, though.
The Shikoku Inu, with fur the colour of dark brown bark, was in good shape, well toned, well defined. He took care of himself. But everyone else was massive. Washboard abs, biceps the size of grapefruits, the works.

The other thing that made Jaeger feel a little uncomfortable was the, uh… furniture.

Alongside those who were currently working out, and the coaches roving around to check their form, there were a fair few who were just… standing there. Stock-still. Some were just spotting the exercisers. Not that weird. But some of them had towels draped over their faces and shoulders. Jaeger even spotted a cat whose physique was a lot like his. He was rigid as a board, parallel to the floor, getting bench-pressed by a yolked white rat. 

Each and every one of them, as far as he could tell, wore wide, contented smiles on their faces. They also all wore a tight red shirt, with black text emblazoned on it:

VOLUNTEER.

…Interesting vibe.

"What's up brother?!" Jaeger got a clap on the back that almost made him faceplant on the squishy mat beneath him. 

"Agh! H-hey!"
He wheeled around with a yelp to see a steel-blue shark towering over him, his skin glistening as brightly as his smile. 
"Welcome to PFP! You're Jaeger, right? I'm Vic! We were texting!"
Oh yeah… Vic was Jaeger's first point of contact when he signed up. Now he had a face to the name. 

…He was also wearing one of those red Volunteer tees.
Come to think of it, he didn't see anyone here who wasn't a Volunteer, or a gym-goer…
"So, first things first." Vic's hand pushed between Jaeger's shoulderblades. "We gotta get you weighed in, check your mass, body fat, all that stuff. It won't take long at all."

"Sounds great…" Jaeger choked hoarsely.
The shark pushed a little harder, nudging Jaeger off balance and forcing him to start walking. 
"Ah-whoa-okay."
"So, what brings you here, buddy?" Vic asked, his voice sharp and friendly… like a Good Cop.
"I just wanted to get out a bit more," Jaeger said, glancing up to make a little eye contact before he brought his eyes back front. "I'm in pretty good shape, but I wanna see if I can push myself a little-"

"Just in here," Vic interrupted.
"-bit… oh, okay…"

It was a small room, just big enough for a chair, and what looked to be a very fancy weighing machine. A large screen sat on a white, aluminium plinth, and there were two large dark paw shaped spots on a platform at the base.

"Cool, right?"
Jaeger looked at the shark, whose grin did not seem to have relaxed at all.
"Mm-hm…" the dog said, nervously wagging. "What's this for?"
"It's just gonna scan you… it measures all the usual stuff - weight, muscle mass, body fat - buuuut, it goes a bit deeper than that. It can tap into your brainwaves - hold still-"
A claw-shaped helmet was pushed into the back of his head - one claw going up over the top between this ears, the other two resting on his cheeks.
"-And using what it picks up, it'll make suggestions for what duties you can volunteer for!"
"Wait… I didn't say I wanted to volunteer-"
"Well, you don't have to, but you'll get a free class credit every time you do a shift!" Vic was giving a very hard sell, and truth be told Jaeger was starting to feel a little intimidated. He could be talked into one shift, maybe. Just one.

"Just put your hands on the markings on the railing," Vic said, "And it'll all make sense when I start the scan."
"…Ok, got it…"
Jaeger did as requested…
And he swore he could feel something his paws rested on the dark, slightly rough markings.
Jaeger wasn't sure if he was hallucinating it, but he felt like there was something vibrating beneath his feet and on his hands. 
…And on his head, for that matter. The small square screen came to life with a soft flicker and chime. 

He couldn't pull his paws away - it was like they were magnetised, clenched claw-like on the railing. The same went for his feet. They stayed rooted.
Jaeger's head felt fuzzy. The harness on the back of his head felt like it was pressing - no, massaging him. Like something was probing around inside him, dusting, fixing… re-arranging.

Images began to flood his brain. The curvature of thick muscles, clenched and tensed to keep weights aloft. Bulging, cresting jockstraps bouncing as their owner skipped rope rapidly. The crevices beneath flexing arms and between thick thighs, seemingly designed for a snout to be nested into.
He drowned in them. He felt like he could smell them, taste them…

Jaeger groaned, his eyes dilating and going unfocused as he stared down at the little screen. The strobing progress bar continued its rightward journey. He watched closely, following it, trying to keep track of it through the constant onslaught of pulsating images, beamed directly into his fragile mind. Each new image made his cock throb in his pants, add another lug of pre-cum to stain his already soaked underwear. 

"There we go! All done!"
Vic's hand clapped Jaeger's shoulder again, though the dog didn't even so much as flinch. He was slumped, eyes like marbles, staring down at the screen as drool oozed from his slightly-parted muzzle.
"Now that that's done, the machine's gonna tell you what your best volunteer role is gonna be!"

"Uh-huh…" Jaeger grunted. He couldn't make any other sounds from his slack, open throat.

What type of volunteer would he be best at being?

A thumping electronic beat reached his ears next, conducted through his skull. 
A voice came through too. It wasn't Vic. But his cadence was the exact same peppy, vaguely aggressive tone.

"Every Gym worth its salt's gotta have some passionate volunteers! The coach and the managers can't be the only ones running things… That's what makes PFP special. That's what makes our Volunteer Vics special. You gotta be like family. Vics gotta look out for their brothers… not just when you're spotting, but all the time. Vics need to see what your brother needs, and be ready to give 'em just that. 

"Greet your brothers at the door, show them what Perfection looks like…"

There was Vic - the shark Vic, at least. He looked just as huge as ever. Jaeger was nowhere near as big. He wouldn't work as that kind of Vic.

"Make sure his posture's just right as you get lifted…" 
A stiff Vic, this one a bat, had a smile as stiff as his body, as he was deadlifted by the wrists and ankles by a burly rhino.
Jaeger's heart sank. He wasn't tall and long enough to be that. 

"Be his Towel…"
Towel?
Yes… Of course! All the images he'd been shown were making his mouth salivate, his nose twitch… those senses were his strongest, the ones that the rest of his body was in thrall to.. There was no purpose more perfect. 
He could picture it now…
All those damp, sweat covered towels hanging over him, his arms, his face… 
The Vic on the screen looked scrawny. Jaeger couldn't even see what their species was, their face was rammed so deep into a musky-looking armpit.

"Or even a Towel Rack!"
A Vic appeared, absolutely covered in towels - and shirts, and jockstraps, their face hidden beneath them all. An outstretched thumbs-up was the only sign of life beneath the mound of musky clothes…
Yes, yes, yes, yes, yes… he could already taste it. He wanted it - NEEDED it so badly. Imagining it was enough to get his whole body wiggling even as his feet and hands remained rooted to the rail and the panel.

"Look at that tail go!" Shark-Vic laughed, though the laughter barely cut through the noise of the dog's vivid hallucination. "Looks like we've got you figured out… Now, we gotta get you fitted for your shirt. You can start with a volunteer shift today, then we can see if you wanna join one of our classes! You didn't have any plans today, did you?"
He did. But he couldn't remember what they were. They were hardly important.

Jaeger got into a routine quicker than he ever had at any gym… or anything he'd ever put his mind to, really. It felt like a calling.

At first, it was three days working out, then two days as Vic. The dog never felt the ache after working out when he was carrying out his duties.
After a month, once his gains were starting to show, it became two days working out, three days Volunteering. Once he hit that all important plateau, nice and buff and ready to be displayed… just one day's working out was needed. Volunteering was what kept him coming back to PFP.

Life just didn't feel quite as rewarding when he wasn't at the gym. He wore the VOLUNTEER shirt underneath his clothes at all times, as if he needed to whip it out on short notice. It was really just to have a constant reminder of what he was good at, and good for. He loved putting on the visor and letting those colours wash and pour over him like a post-workout shower. His tail would wag, his mouth would drool, and the outside world was gone. It was just him, and his Voluntary service, and all the brothers he could help.

"Great workout, brother!" The Volunteer said, each time someone passed him towards the showers. His inflection never changed; as close as someone could get to sounding pre recorded. His fist was outstretched enough for them to give him a quick bump as they passed - each bump like a little rewarding jolt of electricity.

As their one hand bumped his fist, their other hand threw their sweat-soaked jock over his face, or his shoulders. His blank eyes and big smile were covered over by pouch after pouch. He marinated in their moisture and scent, each whiff its own reward.

"Great workout br-mrrnh!"
The Volunteer kept greeting each brother as they passed, though now his voice was muffled by the cotton jock in his mouth, the strap sticking out like an un-swallowed noodle. Each "grrm wrkmr brrmmr" squeezed out the sweet salty nectar onto his tongue. His tight shorts pulsed, his needy cock throbbing within the round null-bulge pouch it had been nestled into. The thick plug in his hole pulsed, too, a further reward for his hard work.

A hand grabbed it, fondling it like a just ripened fruit. The sweaty fabric was yanked out of the Volunteer's mouth, and he looked up. The Volunteer saw a shark smiling down at him(even with the mass he'd put on, the dog was still dwarfed). 

"Hey Vic," the shark said. "I left my towel at home. Help me out."

"Sure thing, Brother!"
Vic loved being a towel. He loved being covered in a brother's sweat, its salt matting his fur and its scent spiralling around in his nostrils. Whatever aches he had drowned in the sweat as his Brother wiped the dog's snout against his arms, his abs, his pits, his ass…

While one hand had Vic buried under the shark's pit, his other hand slid down past the tail, to his butt crack. The shark grabbed and tugged, pulling the plug free with a wet, satisfying pop. 
Vic wasn't left un-filled for long. His vision spun from the shark's underarm to the tiled wall of the shower. His muscles were well toned, very relaxed, so both of the shark's dicks practically glided inside him.
"Hell yeah b-brother!" Vic yipped, relaxing his walls just as he'd been trained.
He pushed his face against the tile wall and pushed his ass right back against the hemi-dicks, squeezing them tight and making sure he'd be stuck there. No way.

The best Vics got to be cocksleeves too, got to fuck their brothers to help them let out some steam. And his hole was well-used. Well-trained. His own version of perfection.