After a few minutes of running around the track, Sam was delighted to see the team come to a stop for a water break. One by one, they each filled a cup with the tainted water and drank it all. Like yesterday’s “experiment,” the effects wouldn’t be visible immediately, but would speed up once more of the water was consumed. Sam settled back and waited for the fireworks to begin as the team started running once more.
After several laps, Sam began to notice small differences in the runners. Pecs a bit larger, quads a bit thicker, shoulders a bit stronger, nothing too noticeable yet. The changes were most visible in Liam and Kristian, as they were already decently muscular to begin with. Sam quietly laughed with excited as they stopped yet again for a water break. Pour, drink. Pour, drink. Pour, drink. As the team set off once more, things began to pick up.
——-
“Damn, my singlet feels tighter than normal today,” the blond, lean Chase complained to Kristian as they ran side by side.
“Do you think that could have something to do with the fact that your dick is over twice the size it used to be?” Kristian panted, his own monster cock flopping back and forth in his overtaxed singlet.
“Not there,” Chase persisted, his brow furrowed. “Everywhere. It’s like my singlet is one size to small now. Huh.”
Unconsciously, he flexed his biceps as they quietly began to swell.
—A few minutes later—
“Water break!” Will called.
Everyone came to a stop by the cooler. As they drank their usual cups of water, Liam focused on Will. The attractive brunette was already in great shape, but he could swear that his back seemed a bit broader, his pecs stuck a bit further out, and his legs seemed a bit more muscular.
“Have you been lifting weights or something?” he asked Will.
“What?” Will responded, swallowing another gulp of water.
“I said have you been lifting weights?”
“Not at all actually. I’ve been so busy that I don’t have time to work out outside of track practice,” Will shrugged. “Why do you ask?”
“I don’t know... you just seem... bigger.”
“Huh,” Will wondered, looking down at himself. “I guess I have put on some muscle.” He looked back up at Liam. “As a matter of fact, I think you have too!”
“Really?” said Liam. “I haven’t been to the gym in months.”
“Huh,” they both thought to themselves.
——
Sam smiled as he watched the field. Now that the team had finished their third water break, things were really picking up. Singlets were definitely getting tight. Round biceps, heavier pecs, powerful legs, and thicker butts were all beginning to show themselves. Because of the runners’ increasingly tight singlets, Sam could even see defined abs rapidly coming into existence. And the runners were finally realizing it.
——
“Kristian something feels wrong,” Liam muttered. “I feel like my singlet is getting tighter really quickly and I don’t like it.”
Kristian nodded in agreement, trying to ignore the feeling that his body was... swelling. “Yeah, I think something’s up. Could the heat be shrinking our uniforms?” he asked hopefully.
“No,” Liam countered. “It’s hot, but not that hot.”
“Water break!” Will called again.
They all came to a stop, seemingly in a hurry to get their water. No one was willing to admit it, but they were all anxious.
Will looked around, beginning to feel nervous. His team looked... different. Bigger. Stronger. But that couldn’t be. Muscles didn’t grow that fast. Of course, neither did penises, but he tried not to think about that. His thoughts were interrupted by a loud ripping noise. Everyone looked over to see a tear through the ass of Chase’s singlet. He had bent over to stretch, but his thicker butt had made other plans. Will’s eyes got wide. Chase was definitely a lot bigger. His slightly hairy chest was straining against the front of his singlet, practically ready to split it open. As Chase nervously drank a gulp of water, Will could see a powerful bicep swell up, one that hasn’t been there earlier. The rest of him had gotten bigger too. His shoulders were broad and powerful, something that wasn’t very characteristic of the previously lean Chase. His legs were stronger too, straining the fabric of his track singlet. He knew it too. Will could tell that Chase was scared. But Chase was looking at him.
Scared, Will looked down, and realized the worst. The same had happened to him. He was big. Really big. His singlet didn’t look like it would last much longer. His mind was reeling as to what could have caused this, but he had no answers. “Let’s go!” he yelled.
Panicked, the team tried to continue onwards, trying to outrun their growing fears. But after a water break, they wouldn’t get very far. 3/4 of the way around the track, Liam stopped. The rest of the team quickly did as well.
“Okay! We obviously all know it!” Liam yelled. “We’re growing again, but this time it’s our muscles!” His singlet emitted painful stretching noises as it was pushed to the limit.
“What do we do!?” Chase yelled. “We’re huge and we’re still growing!”
Will shrugged his strong shoulders. “I don’t know guys! There’s nothing I can do! All we can do is wait and hope it stops.”
They were all startled when the tearing noises began. Small rips began to appear in everyone’s singlets. Everyone diverted their attention to Kristian as he groaned and growled in discomfort.
“There... it... goes-RIIIP.” Kristian exhaled in relief as his heavy pecs split through the front of his singlet. Attention then shifted to Chase, who was having his own issues. “Ah fuck!” Chase growled in pain as his growing quads tore the bottom of his singlet.
But nothing compared to Liam, who had a habit of drinking more water than most. He groaned as his arms swelled again.
“It won’t... last... much... longer!” he yelled as his pecs swelled out once more. Everyone watched in fear as he continued to rapidly grow, his upper body quickly packing on powerful muscle, followed by his lower body swelling with power as it tried to keep up.
Another spurt of growth wracked the redhead’s body as he clenched his teeth. “THERE IT GOES-aaah,” he sighed in relief as the straps of his singlet finally snapped. The others watched, speechless as his tattered singlet slid down off his body, revealing his strong pecs, defined abs, and massive dick which now swung between his legs, free of any restraint.
The redhead looked down in shock at his body, but quickly looked back up as the others finally caught up. Snapping noises alerted the runners as singlets tore and bodies were freed. Kristian was next, as his overtaxed singlet practically exploded off, revealing the tall, buff Swede in all his glory. After a few others, Chase came next, the formerly lean runner staring down in mute shock as he took in his powerful muscles and enormous cock. Finally, after all the others, Will groaned and finally tore out of his spandex restraints, shedding them on the track.
The 15 runners looked around in silence, awe, and fear as they took in the torn, white spandex on the ground, the huge, hanging cocks which had been well-known but not seen by everyone, and the strong, powerful bodies of their formerly lean teammates. They practically looked like gymnasts.
“Holy FUCK!” Chase shouted, not that there was anyone to hear it except his teammates (and the very turned-on Sam). “We’re fucking huge!”
“Holy shit,” Kristian said breathlessly, running his hands through his long blond hair.
Liam looked at Will in shock, taking in the larger version of his captain. After a moment, he smiled, then chuckled. “Can we call practice early?” he asked through a grin.
Will thought for a moment, then burst out laughing. Everyone followed, and finally had a much-needed laugh.
“Sure,” Will laughed, slapping Liam’s broad back. “But lets find some clothes first.” He began to walk towards the locker room, and the others quickly followed.
“This is gonna be a hard one to a explain at the meet,” Chase laughed.