Low Carb and Athletic Performance

Lots of people complain that their athletic performance is reduced with a Low Carbohydrate diet. Dr Volek contends that these issues are due to various reasons:

  1. Insufficient adaption time – it can take between weeks to months to fully adapt to the ketogenic diet. That is because the body is fueled by ketones rather than glucose.
  2. Electrolyte Imbalances – The ketogenic diet causes a shift in the body’s electrolytes and requires supplementation. This is even more the case with athletes who sweat a lot.
  3. Incorrect Amount of Protein – Too little or too much is a problem (between 15% and 25% of calories per day from Protein seems optimal).

See also, the book “The Art and Science of Low Carbohydrate Performance“.

Note that this may be limited to endurance activities rather than higher intensity activities.

…one caveat that anaerobic (ie, weight lifting or sprint) performance is limited by the low muscle glycogen levels induced by a ketogenic diet, and this would strongly discourage its use under most conditions of competitive athletics.


Exercise Equipment

Cast Iron Kettlebells



Power Cage

Hyper/Back Extension Ab Bench

I got more out of my first time on one of these benches than four trips to the Chiropractor.

Pullup Bar


Intermittent Fasting – The Science (pt 2)

Here is another study (Glucose Tolerance and Skeletal Muscle Gene Expression in Response to Alternate Day Fasting).


Glucose and insulin responses to a standard meal were tested in nonobese subjects (eight men and eight women; BMI, 20 to 30 kg/m2) at baseline and after 22 days of alternate day fasting (36 hour fast). Muscle biopsies were obtained from a subset of subjects (n = 11) at baseline and on day 21 (12-hour fast).

The results were:

Glucose response to a meal was slightly impaired in women after 3 weeks of treatment (p < 0.01), but insulin response was unchanged. However, men had no change in glucose response and a significant reduction in insulin response (p < 0.03).

Some significant results:

The protocol was well tolerated, weight loss was 2.5% of initial body weight, resting metabolic rate was unchanged, and fat oxidation, as measured by the respiratory quotient, was increased.

Subjects with type 2 diabetes were excluded.

The insulin response to a meal was not influenced by alternate day fasting in women but was reduced in men (area under the curve: 207 ± 38 to 130 ± 15, p < 0.03; Figure 1B), suggesting improved insulin sensitivity.


Furthermore, the insulin response to the meal was improved in men, suggesting that insulin sensitivity may be increased and not decreased after alternate day fasting.



Bible Fasting

Some verses to ponder on fasting:


Est 4:16

Go, gather together all the Jews that are present in Shushan, and fast ye for me, and neither eat nor drink three days, night or day: I also and my maidens will fast likewise


2Ch 20:3

And Jehoshaphat feared, and set himself to seek the LORD, and proclaimed a fast throughout all Judah.


Mar 2:20

But the days will come, when the bridegroom shall be taken away from them, and then shall they fast in those days.


Joel 2:12
Therefore also now, saith the LORD, turn ye even to me with all your heart, and with fasting, and with weeping, and with mourning:


Act 27:33

And while the day was coming on, Paul besought them all to take meat, saying, This day is the fourteenth day that ye have tarried and continued fasting, having taken nothing.


Protein Sparing Modified Fast (PSMF)

There’s a lot of scientific data concerning Protein Sparing Modified Fasts (PSMF).

Here’s one article (Nitrogen Metabolism and Insulin Requirements in Obese Diabetic Adults on a Protein-Sparing Modified Fast), ).

When this fast was applied to seven obese adult-onset diabetics who were receiving 30–100 units of insulin per day, insulin could be discontinued after 0–19 days (mean, 6.5). In the three patients who had extensive nitrogen-balance studies, balance could be maintained chronically by 1.3 gm. protein per kilogram IBW, despite the gross caloric inadequacy of the diet. The PSMF was tolerated well in an outpatient setting after the initial insulin-withdrawal phase had occurred in the hospital. Significant improvements in blood pressure, lipid abnormalities, parameters of carbohydrate metabolism, and cardiorespiratory, symptoms were associated with weight loss and/or the PSMF. For diabetics with some endogenous insulin reserve, the PSMF offers significant advantages for weight reduction, including preservation of lean body mass (as reflected in nitrogen balance) and withdrawal of exogenous insulin.

Another paper (Multidisciplinary treatment of obesity with a protein-sparing modified fast: results in 668 outpatients. A Palgi, J L Read, I Greenberg, M A Hoefer, B R Bistrian, and G L Blackburn – Full Text) showed excellent results. Here’s the abstract:

Six hundred sixty-eight obese outpatients, 71 per cent (+/- 34) in excess of ideal weight, were enrolled in a multidisciplinary weight control program. The major components of the program included nutrition, education, behavior modification, and exercise. Rapid weight loss was accomplished using a very low calorie (less than 800 kcal) ketogenic diet. Patients adhered to the protein sparing modified fast (PSMF) for 17 +/- 12 weeks and averaged 9 +/- 17 weeks in a refeeding/maintenance program. Mean weight loss was 47 +/- 29 lb (21 +/- 13 kg) at the point of minimum weight and 41 +/- 29 lb (19 +/- 13 kg) at the end of the maintenance period. Systolic and diastolic blood pressure and serum triglycerides fell significantly in men and women. Success in weight loss was greatest in the heaviest patients, those who adhered the longest to the PSMF, and those who stayed the longest in the maintenance program.


Bodyweight Exercises – Part 2

Why Do Bodyweight Exercises?

I wrote a short post about bodyweight exercises last year. Here’s a few of the advantages to doing bodyweight exercises:

  • Doesn’t take up much (if any) floor space
  • Inexpensive – no gym fees
  • Very little equipment required
  • Quicker – no travel time to the gym
  • Less embarrassing – you can do these alone without someone watching
  • Less likely to get hurt than with heavy weights/equipment
  • Muscle gains are “natural” in appearance (as opposed to looking “jacked”)
  • Not cardio focused, but strength focused (although your cardio will also improve)
  • Improve mobility and coordination

One program that I really like the looks of is the StartBodyWeight.com program.


Note – I haven’t tried this particular program myself since I am doing CrossFit but many of the elements are the same as CrossFit. The difference is instead of using heavy weights and doing Olympic style lifting bodyweight training uses the weight of your body as the weight you are lifting. Not a bad place to start since we’ve all got more than enough body weight.


The Start Body Weight program consists of seven basic exercises intended to work each muscle group. These are:

There’s also a warmup period and a cool-down period at the end of the exercises. Each exercise includes rest times between sets as well.


Since it’s unlikely that a person who is starting out can do these exercises, for each of these seven exercises there is a progression of steps to reach the ultimate form of the exercise. With the progression you start with your current abilities. For most of us untrained people that will be in the first of the progressions within that particular exercise.

Example: Pushup Progression

The progression for pushups goes through the following steps:

  1. Wall pushups
  2. Box pushups
  3. Three quarter pushups
  4. Three quarter pushups + Eccentrics
  5. Pushups
  6. Elbows in pushups
  7. Diamond pushups
  8. Uneven pushups
  9. Decline pushups
  10. Decline elbows in pushups
  11. Decline diamond pushups
  12. Wall one arm pushups
  13. Incline one arm pushups
  14. One arm pushups
  15. Decline one arm pushups

Very few people can do #15 (decline one arm pushups) but everyone can do #1 (wall pushups). The idea is to progress over weeks from #1 through #15. There’s a lot of advantage to doing this as a progression compared to other ways which say, maximize the number of pushups. Plus, wouldn’t it be just plain cool to be able to do one-armed pushups?

How Often?

This program is set up to be done three days a week with a day or two of recovery between each workout day. The recovery time between days allows your muscles to rebuild themselves.

How Many Reps?

Each exercise consists of between 4 and 8 repetitions with a 1-2 minute rest between sets. After you can do three sets of 8 reps move to the next exercise in that progression.



Other Bodyweight Programs

Revisiting the Calories-In / Calories-Out (CICO) Model of Weight Loss

The Calories-In / Calories-Out model is often criticized by Low Carb diet advocates and there is evidence that the criticism has some validity. A well designed and executed study compared Low Carb to Low Fat diets (Bonnie J. Brehm, Randy J. Seeley,Stephen R. Daniels, David A. D’Alessio. A Randomized Trial Comparing a Very Low Carbohydrate Diet and a Calorie-Restricted Low Fat Diet on Body Weight and Cardiovascular Risk Factors in Healthy Women. The Journal of Clinical Endocrinology & Metabolism, Volume 88, Issue 4, 1 April 2003, Pages 1617–1623).

The results were very interesting. The Very Low Carb group did quite well on the diet and of course much better than the Low Fat group. But most significantly to this subject was that the Low Fat group weight loss was explained well by their caloric restriction, but the weight loss of the Low Carb test subjects was not accounted for in their caloric intake.

As the study noted:

The mechanism of the enhanced weight loss in the very low carbohydrate diet group relative to the low fat diet group is not clear. Based on dietary records, the reduction in daily caloric intake was similar in the two groups. For the greater weight loss in the very low carbohydrate group to be strictly a result of decreased caloric consumption, they would have had to consume approximately 300 fewer calories/d over the first 3 months relative to the low fat diet group. Although the inaccuracy of dietary records for obese individuals is well documented, it seems unlikely that a systematic discrepancy of this magnitude occurred between groups of subjects who were comparably overweight. Therefore, it is difficult to explain the differences in weight loss between the two groups primarily as a function of differing caloric intake. Despite instructions to maintain baseline levels of activity, it is possible that the women in the very low carbohydrate diet group exercised more than those in the low fat diet group. Additionally, it is possible that consuming a very low carbohydrate diet increases resting or postprandial energy expenditure. The possibility that differences in the macronutrient composition of the diet alter energy expenditure is an interesting question that bears further investigation.

To take it a step further, in this diet they put the Low Fat people on a restricted Calorie diet but the Low Carb test subjects were allowed to eat as much as they wanted. The study noted:

Another unexplained, but important, observation was the spontaneous restriction of food intake in the very low carbohydrate diet group to a level equal to that of the control subjects who were following a prescribed restriction of calories. This raises the possibility that the very low carbohydrate diet may have been more satiating. Previous studies have suggested that, calorie for calorie, protein is more satiating than either carbohydrate or fat, and it may be that the higher consumption of protein in the very low carbohydrate diet group played a role in limiting food intake. Another explanation for restricted food intake in the very low carbohydrate group is that food choices were probably greatly limited by the requirements of minimizing carbohydrate intake, and that dietary adherence per se may have forced caloric restriction due to practical factors. Although it has been proposed that ketosis developing from severe carbohydrate intake contributes to a decrease in appetite, this does not seem likely based on our data. Although the women following the very low carbohydrate diet developed significant ketonemia, the elevation of circulating β-hydroxybutyrate was mild, well below what is seen in other clinical states of ketosis, such as starvation and diabetic ketoacidosis, and was noted only at 3 months. In addition, there was no correlation between the level of plasma β-hydroxybutyrate and weight loss (r = 0.29; P = 0.43).

Keto for the win. Calories-In / Calories-Out loses once again.


Protein-Sparing Modified Weight Loss Studies

There’s a lot of scientific data concerning Protein Sparing Modified Fasts (PSMF). In this post will collect together studies which looked at Protein Sparing Modified Fasts. I expect to add studies to this page over time.