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Greenville, SC

Trimarni is place where athletes and fitness enthusiasts receive motivation, inspiration, education, counseling and coaching in the areas of nutrition, fitness, health, sport nutrition, training and life.

We emphasize a real food diet and our coaching philosophy is simple: Train hard, recover harder. No junk miles but instead, respect for your amazing body. Every time you move your body you do so with a purpose. Our services are designed with your goals in mind so that you can live an active and healthy, balanced lifestyle.


What our athletes are saying.

James Whitsett




Crossing paths with Marni 5 years ago has been a life changing experience for me.

I’m age 53, married with a son and daughter in their early adulthood and live in Clearwater Florida.

I would have to say, I have not had the healthiest lifestyle in the past. I have tried to change this over the years and have made some progress, but until I ran across Marni and started listening to her philosophy, I finally was able to put together a lifestyle that makes me more confident and content with the person I want to be. Even though I am the same person, working with Marni has opened up my eyes in a way that I think and act completely different from my past.

Marni has formally been my triathlon coach for the last 2 years. However, I have followed her blog site for the last 5 years. During this time, she has educated me on nutrition, training and living a balanced lifestyle and has demonstrated how this is done in the way she lives her own life.

The thing I love most about Marni, is she lives by her own philosophy. She is a real life example on how it is done.

So if you are looking for a life changing opportunity, hooking up with Marni as your coach will take you down a path you will never regret.

Stacy Schrunk


As a full-time working mother of two teenage boys my goal to finish Ironman Wisconsin was a lofty one. I wanted to work with Marni because I knew her method of "train smarter-not longer" is exactly what I was looking for. I previously worked with Marni on my nutrition which helped me understand the importance of fueling my body for performance. I purchased the 10 week pre-built Ironman training plan. The plan allowed me to plan each week accordingly and balance work, family and training. Each week I felt myself become stronger and build confidence in my ability as an athlete. I finished Ironman Wisconsin on Sept 8th with no GI issue, no leg cramps, and injuries. I have many happy memories of that day I will carry with me forever. I've inspired so many family members and friends with my accomplishment but I thank Marni for her support as a coach and a friend. Her ability to share her knowledge as a athlete and professional is a invaluable.

Doris Steere

Palo Alto, CA


It's hard to find words big enough to describe how truly incredible Marni is. She genuinely cares for her athletes and goes above and beyond to give us all the tools and preparation to achieve our goals. I fully trust in her methods and never question her tactics. I feel confident in saying that she's made me stronger, more confident, and more balanced. I think what I love most about Marni is that she practices what she preaches and lives by her words.

I challenge you to find anyone else who puts so much of her own heart into her coaching.

Ryan Rager


I started with Trimarni as a nutrition athlete a year and a half ago. After seeing some great changes due to learning about nutrition and practicing it almost every day, I then became a coached athlete. The gains I've made in triathlon and overall fitness in general have been very measurable, including getting me successfully to the starting line and finishing IMFL last year. The most amazing part to me has been having a coach that works with me and the randomness of life and making workouts work around those events, which took the guesswork out of changing missed workouts or altering training plans if an injury came up. Also, the biggest decision in going with Trimarni coaching was that she's a proven winner as an athlete herself, has the wealth of knowledge, education and experience in triathlon/athletics, training and nutrition all in a "one stop shop", so it was a no brainer! Lastly, her demeanor and approach to working with athletes has been great. She isn't someone that is going to stand around cracking a whip and guilt you for not doing something just right or missing a workout, but is honest and clear in communicating what you need to hear. Add it all up, and it's a 'win win', no matter how you look at it!

Nick Hegarty


I purchased and worked with Marni on her pre-built 10 week Ironman training plan. Marni put together a great plan that I was able to follow and understand. The plan put me on a path for a successful and enjoyable Ironman experience. Marni's guidance and expertise were a key part to my success and to my ultimate goal of becoming an Ironman. I look forward to continuing to grow, improve my fitness, live healthy and work with her on my future racing and training.

Christine McKnight

Gansevoort, N.Y.; Finisher, 2013 Ironman World Championships, 65-69 Age Group


Trimarni provided me with invaluable nutritional guidance as I prepared for the 2013 Ironman World Championships in Kona, Hawaii. In the weeks leading up to the race, we used food logs to analyze and fine-tune my training nutrition and then put together a realistic and practical race-day fueling plan. There was a lot of give and take, both by telephone and e-mail. Trimarni gave me a wealth of specific, research-based information that I felt was vital to my success as a 65-year-old athlete. On race day, it all came together. My well-thought-out fueling plan kept me going strong for more than 16 hours of racing. I found Trimarni to be affordable, personally accessible, and most important, enthusiastic about me and my goals as an older athlete. 

Nicole Callan

Fort Collins, CO, 4 time Ironman Finisher and 2 time Ironman World Championship Finisher


After qualifying for Kona for the second time, my fourth IM, I decided I needed additional help with my nutrition. After reading one of Marni's articles, I decided to e-mail her and see if she was a good fit to assist me with my nutrition goals. After going back and forth with her on a few e-mails we decided to schedule a time to talk. Marni was very encouraging and easy to talk with, so I decided to ask her for some 'race day' nutrition assistance. I completed my nutrition logs and sent them to her. She was very fast at responding with helpful tips. After reviewing all her notes multiple times, I was ready to make the necessary changes to boost my performance. After making these changes, the next couple of workouts went extremely well and had a ton of energy after the workout. After the next few log reviews, I started to incorporate more of her recommendations into my race day nutrition and overall lifestyle. After seeing improvements with my racing and training, I was sold So, after racing to a 27 Kona PR, I've decided to continue working with Marni on my 'day-to-day' nutrition. I'm excited to see what I can accomplish with Marni's nutritional assistance. Can't wait to see my new PRs in 2014!!!

Gayle Baldwin

I have no great athletic accomplishments to boast about, no great wins, that is. But I am happy to say I bike, swim and run on a regular schedule. I used to run marathons, and did my training on an empty stomach, sometimes up to two hour runs! I did the same with biking. Of course that left me pretty exhausted. When I contacted Marni through her website! my eating patterns were all over the place. Being a Master's athlete, injuries were becoming multiple and recovery more difficult. With her help, I learned to balance my nutrition to support my activity. She got me through shoulder surgery and foot surgery on top of that.

I have made the mistake of trying out other plans and working with other so-called "nutritionists" which has made me appreciate her balanced and personal approach even more. The two outstanding things about her are her undying enthusiasm and positive support and her appreciation of the joy of food as well as it's function. Let's face it, if somebody tells you to eat five meals a day, each one being chicken, brown rice and green beans, is that fun? Food is a part of culture and the aesthetic of life as well as fuel. One look at her Facebook adventures in Hawaii and Eastern Europe, and you can see what I mean. Finally, Marni will work with each individual, not provide a homogenous plan that everyone has to doggedly follow. Oh, which brings me to the last point...she has a dog who things Mom rocks and dogs are always right about people.

Amie Beasley

Simple. Encouraging. Effective. These are three of the words I use to describe Marni. She uses an approach to nutrition and fitness that anyone can benefit from. I am a mother of three children, wife, PE Teacher, Personal Trainer, and Runner. My most recent marathon was my best yet due to her nutrition counseling and training advice. She gives you small steps to take each day that yield big results in the end. I highly recommend her. She has inspired me to dream big! 

Sara Lane


I began working with Marni a year ago as a nutrition client and cannot believe how much she has helped me. At the time, I was recovering from an injury and wanted to keep my nutrition in check while I was unable to exercise. I worked on nutrition with Marni for three months and was able to return to exercising. She not only provided sound nutrition advice, she guided me with knowledge of what foods would best help me during my recovery. 

Since then, I have used two of her training plans to execute a 10K PR and a sprint triathlon PR. While using her plans, I emailed Marni with questions and race results. I found that she offered a huge amount of support and encouragement, along with excellent nutrition suggestions for pre-race and race situations. My very first response after completing a race would be, I can't wait to share this with Marni!!

Most recently, she has helped me as a mother of two teenage athletes. We have worked together to optimize their nutrition so they can be well fueled for their sports, which is a bigger challenge than one might think.

Over the past year, Marni has motivated me to dream big. She lives by that example and has given me tools not only to race and eat effectively, but to have a few PR's in the process. I couldn't have done it without her thoughtfulness, knowledge, and positive energy.

Jordi Vidal

Fuzhou, China; 45-49 Age group triathlete


In June 2012 one of my students challenged me to do something really difficult for me so they could also have an inspiration to learn language. I am 5'51 tall and at those time I was 210 pounds heavy. I could hardly climb stairs without stopping every minute or so. My student challenged me to lose weight.....that was all. I preferred to focus on a healthy body and healthy lifestyle.

I started by running in the mornings and keeping an almost 100% vegetarian diet. Since I like swimming and riding the bike I decided to sign up for a pre-built training program offered by an online coaching company in Spain. As I trained, and as I read more and more about triathlon online, I noticed that something was missing; nutrition. I sent an email to that coaching company but they answered that they could only provide the exercises, not the nutrition. I joined my first 70.3 in May 2013 in Taiwan. I managed to finished but I suffered with the fueling pre-during and post race. That's when I started to take nutrition seriously and that's when I came across Trimarni Coaching and Marni Sumbal. I read thru many articles and watched and listened to many of her lectures and thought it all made sense so I decided to have a try and write an email to her. I never thought she would answer since she seemed to be really busy. I was positively surprised by her warm answer. I first started booking a nutrition log program with her, followed by a 12 week pre-built tri program. Last August I run the Yeppoon 70.3 Ironman in Australia. I improve my PR by an astonishing 25 minutes and that includes riding the last few miles of the bike on an almost flat rear tire! 

Now I am preparing my first full Ironman which will be in Taupo, New Zealand on March 2014. I could not think of anyone else to guide my steps towards it. Marni is not simply a coach....Marni is an inspiration and someone who gets into your inner self letting you discover that "new person" that we all have within.


Los Angeles, CA


My nutrition journey with Marni began when I happened to come across one of her articles written for the USAT email newsletter. Her article demonstrated a very balanced approach to food and life, one that I was looking for myself. As a recreational triathlete and someone who struggled to have a healthy relationship with food, Marni helped me to both improve how I fueled my body around workouts as well as giving me the knowledge I needed to change how I thought about food during the rest of the day. I not only saw an improvement in how I performed and felt during training and racing, but, more importantly, was able to carry the healthier approach to food through my first pregnancy. I actually felt stronger and more at peace with my body during that time than I ever had before and I attribute the positive change to the guidance that Marni provided. Best of all, I have a very healthy baby girl as a reminder of how amazing the body can be when given the respect and fuel it needs. The benefits I received from my work with Marni will no doubt continue to have a positive effect on my life for many years to come.

Zuzana Blackwood


A couple years ago I decided to go back to school to pursue my dream of becoming a pharmacist. There were many pre-requisites that I had to take to satisfy admission requirements.  I have a type A personality and I like everything in my life to be a certain way. I like a clean house, a weed free garden, a fridge stocked with healthy foods, I like to work out 6 out of 7 days, and I like good grade. After a few weeks of trying to juggle everything I started having acid reflux issues. First, I thought it was coffee so I cut it out. Then I thought it was tomatoes, then peppers, and then chocolate, you name it. After a few weeks of cutting things out I realized that I couldn’t eat anything without getting reflux. Unfortunately, medication did not work for me so I started looking for another alternative. At that point I had been following Marni on Facebook and her blog for a while. I was inspired by how healthy, happy, and positive her outlook on life was, so I decided to contact her and hire her to create a new eating plan for me. Marni’s approach worked great for me. She was very  detailed in gathering information about who I was, how I lived, what my eating habits were, what I liked and disliked, what were the important things in my life. I especially appreciated that the changes we made were gradual. I started incorporating one thing at a time. What I really appreciated was that it was not about cutting things out. Marni explained that there were no good foods versus bad foods, as long as they were eaten in a right proportion at a right time. 

Her recipes helped me incorporate different fruits and vegetables into my diet. I am happy to say that I developed a solid eating plan. School is busier than ever, so it is even more important for me to pay attention to what I put into my body. There are still many days when my time and choices are very limited, but I feel that I am well equipped with “Marni tools “to make the best choices available. If I am unsure, I just ask myself “WWMD (What would Marni do)?” Marni continues to inspire me with her blog, recipes, and just being a positive person full of vitality.

Katie Aguilar

I chose to work with Marni because she is a registered dietitian, Ironman triathlete, and a vegetarian. When I would read her blog I just felt like she was speaking to me. I knew I wanted to work with her. 

I train not for an event, but as a lifestyle. I have a long-term goal. I know I am in this for the long run. I need a long-term, sustainable life-style and not a quick solution.  She helped me place my focus towards whole foods: more whole grains, fruits and vegetables. More importantly, and where I was REALLY lacking, she helped me get a much better balance of fat, protein and carbs in my diet. Very importantly she educated me on getting that correct balance and how to achieve that balance with a busy training (and sometimes traveling) lifestyle. 

Since working with Marni, my blood work numbers (HDL, LDL, and triglycerides) have dropped. I have lost weight, but that is secondary to my feeling, training and racing stronger. I have felt energized and ready for training sessions (even with short recovery periods) and feel strong throughout training. My strength has increased and my race times have dropped.

Marni doesn’t give fast solutions, but works with you on areas where you can achieve long-term success and builds from there. 

Marni is helping me towards my lifestyle and long-term goals. I often recommend Marni to my friends and colleagues as being someone easy to speak with, and very helpful in helping people achieve their personal goals.

Rick Van Tuyl

Laguna Hills, CA

I found Trimarni on a triathlon forum asking for a nutritionist recommendation. After a phone consultation, I decided to hire her. I wanted to clean up my diet and lose a few pounds. She helped me by installing 'wise food choices' and at the same time she worked with me for my race day nutrition plan (I was getting ready for Ironman Arizona). I still use 'The Plan' for my long training days as well as my race days. I still keep in contact with Marni via Facebook and enjoy following her blog. She usually has a few nuggets that I can employ in my training or racing. If you are looking for a reliable, educated, and inspiration nutritionist, I would very seriously consider using Trimarni.  

Terry Repp

Palm Harbor, Fl; Womens 55-59 age group


TriMarni Coaching and Nutrition has benefited my wonderfully active lifestyle in so many ways! Marni was one of the first coaches I ever used to understand my nutrition needs and to train for my first 70.3 Ironman triathlon. I learned so much about having a quality training plan and qualified for the 70.3 World Championships! I love the website for the amazingly healthy recipes and tips on triathlon gear and clothing too! Marni has taught me as a masters endurance athlete to dream BIG and just last year I completed Ironman Florida in the top 10 in my age group ! Marni and Karel both inspire with the lifestyle they lead and pass on this information to us in a way that makes me want to work hard for different goals. One of the many things they teach is the importance of recovery, healthy eating and fueling for my next big adventure! I work in the Parks and Recreation field and am fortunate I can pass on this great information to the families, friends and training partners and groups I am involved with. Thank you so much TriMarni Coaching and Nutrition! 

Cindy Stellmach


In the few years I have worked with TriMarni, I have been able to accomplish more than I thought possible…several half marathons, marathon, duathlon, Ragnar. The key race that led me to Marni was just two short months prior to racing my first marathon, with using a program I found online that was not working for me, I was having issues with dehydration on long runs. With desperation and anxiety, I asked Marni to help me cross the finish line that I had trained so hard to get to. She graciously accepted the challenge and we were able to get me where I needed to be for race day. It was the most amazing day of my life and I have her to thank for getting me there. We have gone on to work together with nutrition, proper fueling for races, and finding balance…but most of all the emotional strength she has given me - believing in me when I didn't believe in myself. The little reminders to 'dream big' and 'anything is possible' are constantly there. 

As a runner knowing the importance of cross training, I've had the opportunity to experience Karel's expertise first-hand with the purchase of my first Trek bike. He took his time to teach me everything about the bike to include changing a flat tire! My first day on the trail with my new bike I crashed and Karel & Marni were just an email/text away to offer advice and the bike was fixed by the end of the day. They are a great team and have a genuine desire to see others succeed in life & sport. 

As a novice athlete, another aspect of TriMarni that I appreciate so very much is product recommendations. When I need something, Marni is just an email away and is very honest with her opinions on products available for whatever I need and has always been spot-on with her recommendations. This has saved me so much time sifting through conflicting research/product reviews.

TriMarni always goes the extra mile to not only talk the talk, but walk the walk. She lives the lifestyle that she encourages for others. Active, healthy, and happy -.a stellar example of how we all should value ourselves and our lives. Marni is always eager to help and her positive energy is contagious. Marni is truly a blessing in my life and I am so grateful to have her as my coach.

Laura Gersten

When I signed up for Ironman Lake Placid, I knew I wanted a coach to guide me through my first Ironman journey. I had been reading Trimarni for quite some time and knew Marni would be a great coach for me. I was right. Marni was able to guide me to successfully complete my first Ironman with not only a healthy body but also a healthy mind. Marni is a coach that not only understands the sport in all levels but her nutritional background adds an additional element to her coaching. Marni never put my dreams down and always pushed me to keep dreaming big and reach for my goals.

Gary Bonacorsi

65-69 age group triathlete
Seminole Fl.

Marni has been my coach now for about 5 years and I have aged up now to be 65 years old. We have had a lot of successes together but there is a new success that we have been experiencing and that is dealing with age related issues/injury's. Marni always provides training that is age appropriate to keep me in the game and yet performing at my maximum. We do all the preliminary things first, to strengthen my body before we work on the stresses that will improve my endurance and speed to help prevent injury. But when leg or back issues (for example) arises that may prevent me from general training, I first have the specific issue diagnosed by my doctor and then I report all the information to Marni. Marni then focuses on what we CAN do safely and has actually rewritten my current training plans that she has already invested time in. In addition, Marni takes personal interest in that specific injury issue and wants to kept current so that what we are doing, keeps us moving forward towards healing and ultimately our racing/training goals. Marni has posted great articles on her blog regarding injury based training. She has a very effective plan on how to deal with the inevitable injury that we will all face at one time or another, if you are 20 or 65 years old. Because of Marni's passion and concern for her athletes, she will unselfishly stop what she is doing and has addressed my specific training needs. I am so thankful to have found TriMarni Coaching.

Taffy Remisiewicz

Jacksonville, FL

I began working with Marni utilizing her nutrition services after developing a food allergy in 2011.    After my own research, I had a good understanding of what not to eat, and began to explore which foods were best.  Marni helped me understand the importance of eating the right foods and why they were good for me.  She helped to significantly improve my overall outlook and attitude on how to view food as nutrition and ‘fuel’ for my body.  Marni’s knowledge, motivational and inspirational outlook on nutrition and exercise helped me fit all the pieces of my own nutrition and training together.  

Rosey Atkins


I had the pleasure of working with Marni and it was an invaluable experience. With her it's not about losing weight or winning a race, it's about how you feel. How food and exercise is meant to fuel and energize your body. She teaches you how to eat in away that every day, step by step, you start to feel better and better. It gets to the point that you feel so amazing that you would be foolish not to eat plant strong meals.