Popular fitness coach Justin Mihaly just put bodybuilder Will Tennyson through one of the most brutal arm workouts of his career—and it didn’t involve heavy weights or impressive numbers.
In a recent training session, Mihaly demonstrated his signature “lengthened partials” method, combining strategic exercise sequencing with time-under-tension techniques that left Tennyson grimacing through sets with just 7 and 12-pound dumbbells.
The approach represents a dramatic shift from traditional bodybuilding protocols, prioritizing muscle stimulus over ego lifting.
And for Tennyson, who’s recovering from a minor tricep strain, the timing couldn’t have been better.
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The Injury That Changed Everything
Tennyson opened up about how a recent injury forced him to reconsider his training approach entirely.
About a week ago, I had a couple nights of rough sleep, was dehydrated, was doing bent over rows, and I felt my tricep was like a little sore. I need to learn because every single time I’ve ever injured myself, it’s been the same thing. It’s lack of sleep, high stress, dehydrated.
He described feeling a “velcro-like” sensation in his tricep during the movement—a warning sign he’d experienced before but sometimes pushed through.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
The pattern was undeniable. Poor sleep, dehydration, and high stress created the perfect storm for injury, even during exercises that shouldn’t stress the affected muscle.
Rehabilitation Through Controlled Tension
Rather than complete rest, Mihaly prescribed active recovery using adjustable cable machines that allowed Tennyson to control resistance precisely.
This thing is beautiful because you control the tension with your other arm and mentally you feel it. So if I start to hurt a little bit, I just let go off the other arm and I keep moving and I’m strengthening and retraining my brain that it’s not injured and it can get stronger and heal.
The psychological component proved just as important as the physical stimulus. By maintaining movement without pain, Tennyson could prevent the mental association between exercise and injury that often prolongs recovery.
Deconstructing The Chest Protocol
Mihaly’s chest training philosophy centers on accentuating different portions of the strength curve across multiple exercises.
The sequence moved strategically from lengthened positions to shortened positions, ensuring complete muscular fatigue.
Think of this as the bottom of an incline press. That’s what we’re emulating with this. So it’s lift, stretch, big stretch in the upper chest. This one’s two to four working sets, but realistically like three is going to be the sweet spot.
The tempo work was unforgiving. Each repetition followed a strict cadence—five-second squeeze, four-second squeeze, descending all the way down to one-second contractions until failure.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Why Range Of Motion Matters Differently
Throughout the session, Mihaly emphasized controlling range based on the exercise’s purpose rather than chasing full extension every time.
For lengthened-position work, maximal stretch took priority. For shortened-position exercises, peak contraction mattered most.
The instruction “don’t worry about stretch, just max depth on the squeeze” appeared repeatedly, highlighting how different exercises serve different mechanical purposes within the same workout.
The Four-Phase Bicep Destruction
Mihaly’s arm specialization protocol divided bicep work into four distinct phases, each targeting different strength curves and muscle actions.
- Phase One: Fully lengthened position with accentuated stretch for 15-20 reps
- Phase Two: Standing supinating strict curls for 8-10 reps (mid-range emphasis)
- Phase Three: Cheat-up, controlled-down repetitions accentuating the eccentric
- Phase Four: Partial reps in shortened position with arms against sides for 15 neutral-grip contractions
The instruction during phase two captured the progression perfectly.
Supernating curl strict until we can’t. Don’t cheat it yet. Just squeeze. Good. Now we’re cheating. Here we go. Good. Don’t let the chin drop. Try to shorten all the way. Cheat it to all the way shortened.
Each phase systematically fatigued different portions of the bicep’s strength curve, preventing any area from being undertrained.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
When Seven Pounds Feels Like Seventy
Tennyson joked about the optics of struggling with ultralight weights, but the joke revealed something deeper about training culture.
Be a crazy thumbnail to have like grinding it out through a set with 7 and 12 pounds just like grimacing. This is what it’s come to.
The comment exposed how social media fitness often prioritizes impressive numbers over effective stimulus. True muscle growth doesn’t always look impressive on camera.
Controlled tension with light loads frequently produces superior hypertrophy compared to heavy weights moved with poor form or incomplete ranges.
Tricep Training Through Injury
The tricep protocol became both therapeutic and growth-promoting, addressing Tennyson’s injury while maintaining training stimulus.
Mihaly structured three phases: pushdowns for 20-30 seconds maximal tension, skull crushers for another 20-30 seconds, then high-rep finishing work targeting approximately 45 seconds time-under-tension.
So it’s going to be a ton of burn. We’re not accentuating as many portions of the strength curve, but you’re getting good tension and good programming there. And then we shove a ton of blood into it.
The approach prioritized continuous tension over heavy loading, allowing Tennyson to train through discomfort without risking further damage.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
The Fifteen-Second Rule
During the final tricep movement, Mihaly’s coaching revealed where real muscle growth happens—not in the easy reps, but in the painful final seconds.
Fifteen seconds. Good squeeze. Good squeeze. These are the fruitful reps. This is where you can get a really good stimulus. So just control it. Good intention.
The mental challenge became as significant as the physical one. Maintaining perfect form and tension while muscles screamed required focus most lifters never develop.
The Ten-Minute Back Squat Finisher
After demolishing Tennyson’s arms, Mihaly prescribed what he called a “Tom Platz special”—ten minutes of continuous back squats.
The protocol called for selecting a 10-12 rep maximum weight, then performing ten sets of 10-12 reps with only 20 seconds rest between sets.
That’s over 100 total repetitions in slightly more than ten minutes, with descending loads as fatigue accumulated.
It’s like one of my favorite—you’ve got five minutes, what can I do that’s going to… Same thing for calves, which most people don’t want to do that for calves, but if you do a 10 to 12 rep max, 10 sets with 20 seconds in between.
Mihaly explained the method works because load remains high enough to recruit fast-twitch muscle fibers—unlike low-intensity activities like walking that never generate sufficient mechanical tension.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Controlled Tempo Under Extreme Fatigue
Even as exhaustion mounted, Mihaly demanded strict adherence to tempo: one second up, two seconds down, zero momentum.
The coaching cues came rapid-fire as Tennyson’s form began deteriorating.
Really push the arms away. Try to keep the shoulders depressed. Right back up. Right back up. No pause. One more. You have 12. You have 12.
Between sets, Tennyson had exactly 20 seconds—barely enough time to catch his breath before the countdown restarted.
Lateral Raises: Death By A Thousand Cuts
The session concluded with what Mihaly called “spam lateral raises”—high-repetition shoulder work that proved deceptively brutal.
After everything that came before, even basic lateral movements became agonizing as accumulated fatigue prevented proper recovery.
Tennyson acknowledged how different this training felt compared to his usual content.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
Feel like I haven’t trained like hypertrophy in a while. Everything is just so like burny. Feel like I owe my YouTube a sincere apology for the lack of fun training and intensity.
But Mihaly reframed the perspective, noting two distinct training populations exist—those seeking maximum intensity and those in life seasons requiring modified approaches.
Training For Your Season Of Life
The philosophical shift matters more than the specific exercises.
Effective training doesn’t always mean maximum weights or Instagram-worthy performances. Sometimes the most productive sessions involve injury recovery, technique refinement, and metabolic stress with lighter loads.
Tennyson finished with a “nasty pump” despite using weights far below his capabilities—proof that stimulus, not absolute load, drives adaptation.
The session demonstrated how strategic programming, controlled tension, and mental fortitude can produce remarkable results regardless of the numbers on the weight stack.
