Golf Science – Ph.D.’s and the New Bryson

Golf Science – Ph.D.’s and the New Bryson

Bryson DeChambeau, the man who wants to “conquer” golf, is the name on every golf fan’s lips these days, because golfers are always endlessly fascinated by ball speed and how to increase it. While the average ball speed on the PGA Tour is 170 mph, Bryson has changed his diet and exercise regimens and made changes to his golf swing to have a measured ball speed during competition of up to 195 mph (resulting in drives of about 340 to 350 yards) , while in training he has even reached 200 mph (Mike Purkey, June 16, 2020 in Morning Read). Lots of golfers have asked, “Is this sustainable? What might be the long-term effects of all this on his overall health and with respect to injury? Can he win on a consistent basis with the increased distance?” The only scientific manner in which to respond to such speculation is by asking the experts.

The New Diet

Based on statements to the media by DeChambeau (Dylan Diether, June 30, 2020, He follows what he terms an “Overlying principle of a two-to-one carb-to-protein ratio”. His breakfast is typically four eggs, five pieces of bacon, some toast and two Orgain protein shakes. He snacks on GoMacro bars, a peanut butter and jelly sandwich, or a protein drink. On the golf course and after the round he has 2-3 protein drinks. His dinner consists of steak, potatoes and two protein shakes. His daily diet thus includes 6 – 7 Orgain shakes. Overall he estimated his caloric intake to be 3,000-3,500 calories per day, since October 2019.

DeChambeau in 2018

Expert Opinion by 

Nancy M. DiMarco, PhD, RDN, CSSD, FACSM 

Professor Emerita of Texas Woman’s University, Department of Nutrition and Food Sciences. Former Director of the Institute for Women’s Health. Former Director of the Master’s Program in Exercise and Sports Nutrition. Board certified specialist in Sports Nutrition (Academy of Nutrition and Dietetics).

Bryson was 195 lbs and now weighs 240. He is is 6’1” (185 cm and 109 kg). His current diet (I gave him the benefit of the doubt about portion sizes or amounts so it is probably undercalculated) is ~4200 kcals, of which 250 g carbohydrates, 345 g protein, and 209 g fat – that translates to 24% of calories from carbohydrates, 33% from protein and 45% fat. Each Orgain shake alone would add 500 kcals to his daily intake.

He currently consumes 2.3g/kg bodyweight of carbohydrates, 3.2g/kg of protein, and 2 g/kg fat per day. Based upon current sports nutrition experts, golf pros macronutrient consumption should be 3 – 5 g/kg bodyweight of carbohydrates, 1.2 – 1.7 g/kg protein and 1g/kg fat per day. Golfers are recommended to stay on the lower end of the macronutrient intake range because golf is not a high intensity sport. In fact, according to Zunzer (2013) in the Journal of Sports Sciences (Energy Expenditure and Sex Differences of Golf Playing), male golfers have an average energy expenditure of 926 kcals per 18-hole round of golf, while walking. If DeChambeau is working out on a regular basis with high intensity, then I would use the upper end of that range. 

DeChambeau in 2020

Overall it can be seen that he is nowhere near the estimations he reports, and is consuming very large amounts of both protein and fat. My thought would be that he gained a lot of weight but most of it is fat weight. He mentions in the article that he gets a ratio of 2:1 carbohydrate to protein and that is not true at all – he is getting about 0.7:1 carbohydrate to protein, again attesting to his very high protein intake and minimal carbohydrate intake. Many athletes have the misconception they need tons of protein but the body can only utilize up to about 2.2 g/kg of bodyweight protein per day. The rest of it is converted into urea and excreted as urine and/or stored as additional fat. 

It would be interesting to have him keep an accurate diet record and also have a body composition assessment done through a Dexa Scan to see what his percent body fat and lean mass are, as they would tell the story of what he has accomplished.  

Is the diet sustainable long-term? 

As he is so young, he can continue this diet for a long time but it won’t be without problems. It lacks fiber, vitamins and minerals from a variety of fruits and vegetables, including vitamin C, vitamin A, potassium – all necessary for complete health and longevity. 

What could the long-term health effects of the diet be?

The overall long term health effects may include increased risk for cardiovascular disease because of the reliance on bacon and also steak as major sources of both fat and protein. But without details of his exercise regimen, especially the intensity of the workout, I can only speculate. I am really more concerned about long term effects of lack of these other nutrients in the diet – especially vitamins A, C as they are involved in immune function, wound healing and sight. The lack of potassium in the diet is problematic long term and may put him at increased risk of hypertension.

Which aspect of his new regimens helped him gain 30-40 yards of ball distance?

That is definitely a function of his training – he gained lean body mass as well as fat, but without knowing his actual body composition, again I can only speculate as to what caused the increase in strength gains.

The New Exercise Regimen

Based on statements to the media by DeChambeau (including to Dylan Diether and Luke Kerr Dineen, June 30, 2020,  He completes 1.5 workouts per day, at least one hour per session. His focus is on his core as he has a bad back. He works through a full range of trunk flexion and extension, rotation, and side bending movements to be able to tolerate any amount of force. He has acquired an entire range of exercise machines which allow him to reach end range of motion to maintain his flexibility, stability and motion for the golf swing, bilaterally, and with slightly lighter loads. His fitness advice for the past two years has come from Greg Roskopf who has developed Muscle Activation Techniques (MAT). He also works on training each muscle in isolation, does some body weight exercises and even works on strengthening his grip.

Expert Opinion by 

Keith Baar, PhD, MA

Molecular exercise physiologist at UC Davis. Works with elite athletes. Has a specific interest in the molecular response of the musculoskeletal system to nutrition and loading as a function of age. Scientific advisor to numerous professional and Olympic organizations, advising on protocols to maximize the effects of training for both endurance and strength while minimizing injury.

As with many things in the health and fitness world, there is little evidence behind any of the claims made. This looks to me like a series of endorsement deals wrapped up in a nice package.

As with many fitness claims, there is a small amount of truth at the base of all of the trappings/embellishments that are added to provide the marketability. 

The true part is that being strong through the full range of motion is important for decreasing injuries. The thing about his program that might allow him to do this is that he is isolating muscles using machines. With any machine (not just the brand this golfer is hocking) you can better address weaknesses in specific muscles and together with training and practice this can improve performance. It is far better than when people focus on “functional moves” such as squats and deadlifts, where technique becomes really important and it is very hard to get strength through the full range. As for MAT, I don’t know enough about this to say what it would do for an athlete, but the idea that a muscle is not contracting is something that a lot of people say, without any evidence. 

As far as the adding 40 lbs of muscle in 4-5 months, this would be really hard to do for anyone who did not start off in an underfed state. I added ~30lbs in a couple of months in my twenties, but I went from someone with an eating disorder who was extremely underweight to eating tons of everything and lifting really heavy weights with one of the best football teams in the world. I added a lot of muscle, but also a good amount of fat. From the pictures of DeChambeau that I found online, that might be what happened here. Gaining muscle and strength is quite an addictive activity. So, best case he started eating a ton (as he purports to have) and lifting weights to failure, and got big naturally. I’d prefer not to theorize as to the worst case.

What specifically caused his performance improvement of 30-40 yards of increase in ball distance? 

I would think that the increased performance is the result of increased strength and possibly a small amount from the increase in range of motion.


What would be the injury risks of the diet and exercise regimen he followed to achieve what he has?

If done properly, for an athlete like this who is using machines, loading through the full range, lifting a heavy weight and going to failure, there would be minimal risk of injury. Injury would result more from lifting heavy weights with poor form using Olympic and/or power lifts.


What about the fat gained and the potential for any long-term health issues?

One long term concern might be whether he can drop the weight when he is done. If he can maintain his muscle a lot of the fat will be lost over time, given the increase in basal metabolic rate with the extra muscle.


The New Golf-Related Changes

Based on statements to the media by DeChambeau (including to Dylan Diether and Luke Kerr Dineen, June 30, 2020,  Bryson has always had specific theories of the golf swing that he would hold to, no matter what. Previously it was having his club shaft on a single plane from address to impact. Currently, according to Kerr Dineen, he wants his arms locked into an end-range-of-motion position from which they will not rotate anymore. In a Swing Expeditions episode, discussing this with golf instructor Chris Como, he said this was in order to avoid pulling left, something he wishes to completely eliminate from his swing. Additionally, DeChambeau is trying to add movement to increase swing momentum as he tries to hit the ball further and further. He presses into the ground with his lead foot to move his body mass away from target during the backswing so that he can load it going back and thus load it going through. Bryson has additionally changed his driver swing to be approximately 5° on the upswing at impact to maximize launch conditions and thus ball distance.

Additionally, in late 2019 DeChambeau was reported to be hitting a Cobra King SpeedZone driver with a 4.8° loft (Jonathan Wall, December 12, 2019,

So what should one make of the multifactorial approach Bryson DeChambeau has taken to increasing ball distance in his game?

Expert Opinion by 

Kiran Kanwar, PhD, MS

MS in sports science and nutrition, PhD in biomechanics and anatomy. LPGA Master Professional (Thesis in “types and causes of golf swing-related injury”). Special interest in researching golf swing postures and movements that improve performance and reduce injury, with over 27 years of research in the field.

To begin with, it must be said that few in sports would have the sheer determination and motivation to follow through on so many major changes. Greater strength and a lower-lofted driver will certainly increase distance. And driving distance is highly correlated with better scores. However, Bryson DeChambeau also had a high strokes-gained score for putting during the Rocket Mortgage Classic that he won in July 2020 indicating that he improved his putting as much as his off-the-tee shots. What caused him to miss the cut the very next week, when Jack Nicklaus set up his Muirfield Village course to be extremely challenging during the Memorial Tournament?


In high ambient temperatures it is known that body heat production increases with higher protein intakes – could there have been some discomfort involved during many hours on the golf course in high-summer? Moreover, there is known to be a higher metabolic cost for walking in obese (body mass index > 30) people compared to normal weight individuals (and Bryson’s is now in the obese category at 31.7) – has that aspect been considered, as professional golfers must walk for several miles during a round of golf?


Bryson’s exercise routine does not seem to have addressed (or may have increased) the kyphosis (forward curve) in his thoracic spine (mid-back). This might be an issue in generating trail shoulder external rotation during the backswing, which may in turn affect his ability to deliver the club to the ball adequately from the inside.

Anxiety, Arousal and Personality

It is known that in conditions of high arousal, perception becomes less effective and attention to sensory cues may be lost. This would be most relevant with a swing that requires downswing thoughts for its successful execution, as a downswing lasts only 1/3rd s for average golfers, and much less for faster, more athletic golfers.

One author has suggested, based on the inverted-U hypothesis of arousal and performance, that the peak of a golfer’s inverted U should be at lower levels of arousal, which also makes sense based on the loss of perception, especially if it is proprioceptive in nature, telling the golfer where his body is in space, and allowing for some last-minute swing changes. What is DeChambeau’s level of arousal, especially during the last few holes of a 72-hole event, when he appears to be dropping some shots? Additionally, sports-related anxiety is known to lead to an increased risk for injury and a delay in the time required for rehabilitation after injury. 

The stress response interacts with physiological and attentional aspects and results in increased muscle tension, narrowing of the visual field and increased distractibility. When combined with specific personality traits this can lead to performance issues. What are Bryson’s personality traits?

Golf Swing

While many in the golf media have remarked upon DeChambeau’s considerable accuracy given his substantial driving distance, this aspect can change under conditions of pressure/arousal/anxiety. It only requires a small change in motion for directional inconsistencies to arise, and both slices and pull-hooks can result at random, mainly from torso positioning. A slight “hanging back” during the downswing will result in a slice, and conversely, excessive torso rotation towards target can result in a forearm that is pulled into exaggerated supination and rotates the club closed for a hook. 

A solution that would apply to all professional golfers is to manage the proximal parts (torso) better. While it is true that downswing “weight shift” is essential to the creation of some starting momentum for the swing, a very large away-from-target backswing weight shift, if slightly mistimed, might cause excessive hanging back and a slice. Simply moving the arms away from target during the backswing can create adequate backswing weight shift!

At the same time, the only way to prevent an excessively leftward shot is to have the trail side of the torso, specifically the trail shoulder joint behind the trail toe at impact, and thus the lead shoulder pointing down the target line and not left of it (for a right-handed golfer). It is not enough to merely position the lead arm in a specific position to avoid the pull or pull hook shots. Many golf swing theories lack adequate research or even a sound theoretical foundation based on human structural capabilities.

In conclusion, it is essential for a golfer (especially a “Mad-Scientist” who is endlessly fascinated by science) wishing to maximize performance gains while reducing injury risk to work with researchers who bring to the table many years of relevant knowledge acquisition as well as research in their fields of expertise.