Purpose-driven programming
Every session has intent. Training is a system designed around your goals, background, and constraints, not a collection of random workouts.
Online Triathlon Coach & Endurance Coaching
Where purpose is forged into performance.
Premium 1-on-1 personalized triathlon and endurance coaching for athletes who want structure, clarity, and purpose guiding every aspect of their training.
Triathlon coaching, USA-wide
A triathlon coach in your corner, wherever you train.
Foundry Athletics Co. is an online triathlon and endurance coaching company led by Coach Sean Fenoff, a USA Triathlon Level 1 certified triathlon coach based in Bethlehem, Pennsylvania.
We coach triathletes, runners, and endurance athletes across the USA, from a first sprint triathlon to a full Ironman and World Championship qualification. Every plan is built individually in TrainingPeaks and adjusted week to week through direct communication with your coach, not a template or an app.
Training in Pennsylvania, New Jersey, New York, or New England? See triathlon coaching for the Northeast.
The Foundry difference
Coaching built with intent.
Foundry Athletics Co. is built on one belief: performance isn't rushed. It's forged, through consistency, clarity, trust, and open communication.
Communication first
Coaching is collaborative, not automated. Honest feedback and real-time adjustments keep the plan evolving with you.
Built for longevity
We develop resilient athletes, not short-term fitness spikes, so you can train consistently and perform year after year.
Coaching services
Support that fits the athlete.
Coaching designed around each athlete, not a template. Every service is built for clarity, accountability, and long-term development.
Personalized Coaching
Fully customized coaching for triathlon, running, or single-sport endurance athletes, built around your goals, experience, and lifestyle.
Best forAthletes who want structure, accountability, and long-term progression.
Youth & Development Coaching
Building strong athletes from the ground up, with a focus on technical skill, consistency, and long-term development over early burnout.
Best forHigh school athletes seeking extra structure alongside Cross Country, Track, or Swimming.
Swim Form Analysis
An in-depth look at your stroke, by video or in a 30-minute in-person session, with a written breakdown and improvement plan.
Best forAthletes with direction in their training who need help with swim technique.
Meet your coach
15+ years in endurance sport.
Coach Sean Fenoff founded Foundry Athletics Co. to build a coaching environment defined by structure, communication, and long-term athlete development.
- Kona2× Ironman World Championship qualifier, raced once
- 2×Age-group wins at the Ironman distance
- NationalMultiple USAT Points Race championships & All-American honors
- 5+ yrsHead Coach, Saucon Valley Swim Team
Foundry Files
Latest from the blog.
Foundry Files No. 005: The Adaptation of Adversity
Lessons from a rough Ironman Lake Placid before Kona: why adaptability, not the perfect race, separates good endurance athletes from great ones.
Read the post →Foundry Files No. 004: Start Your Season Strong
No-nonsense triathlon race tips for your first race of the season: pre-race habits, swim, transitions, bike and run pacing, and race strategy.
Read the post →Foundry Files No. 003: The Cost of Racing
Racing is one of the biggest stressors in a training cycle. Why racing too often stalls fitness, and how to choose races that support your build.
Read the post →How to get started
Four steps to your first block.
Reach out
Send a text, an email, or the coaching application.
Intro call
Coach Sean schedules a call to talk through your goals, experience, and what you want in a coach.
Onboarding
Sign the coaching agreement and get set up on TrainingPeaks.
Train
Welcome to Foundry Athletics Co. coaching.
What does a triathlon coach do?
A triathlon coach designs and adjusts your swim, bike, run, and strength training around your goals, schedule, and current fitness, then guides race planning, pacing, and nutrition. At Foundry Athletics Co., Coach Sean Fenoff builds each week individually in TrainingPeaks, reviews your sessions, and adjusts the plan as training and life change.
Do you offer online triathlon coaching anywhere in the USA?
Yes. Foundry Athletics Co. coaches athletes across the United States online through TrainingPeaks, text, and Google Meet. Coach Sean is based in Bethlehem, Pennsylvania, and athletes within about 90 minutes of the Lehigh Valley can also join in-person group training sessions held 2-3 weekends each month.
Do you coach beginner triathletes?
Yes. Foundry coaches triathletes from their first sprint race through full Ironman, as well as experienced age-groupers chasing PRs and World Championship qualification. Plans are built around your experience, so newer athletes get structure and skill development without doing too much too soon.
What is endurance coaching?
Endurance coaching is individualized training guidance for sports like triathlon, running, cycling, and swimming. Foundry Athletics Co. offers 1-on-1 coaching for triathlon, running, and single-sport goals, youth and development coaching for high school athletes, one-time performance consults, and swim form analysis.
What qualifications does Coach Sean have?
Sean Fenoff holds the USA Triathlon Level 1 Coaching Certification, has 5+ years of coaching experience, and has coached athletes to World Championship qualification. He also brings 15+ years of his own endurance racing, including two Ironman age-group wins and two Ironman World Championship qualifications, racing the World Championship in Kona.
Ready to train with purpose?
Let's build an approach around your goals.