This is the first of a three video series about exercise.
Do plant based diets have an impact on fitness?
What are the best times to workout?
Watch the series to find out.
"Improving VO2 Max: A Look at Vegetarian and Vegan Athletes"
In my video about comparing vegetarian and vegan athletic performance,
endurance, and strength, I discussed a 2020 study that found
that vegan athletes—even though they were significantly older—
had significantly superior aerobic capacity and endurance,
lasting 25 percent longer on a time-to-exhaustion cycling test.
The question is why?
One potential mechanism that could explain the greater level
of endurance performance in vegans may be a higher amount
of carbohydrate intake, which could lead to better endurance
performance through higher muscle glycogen storage.
Other potential mechanisms that may explain the better endurance
performance in vegans could be due to the anti-oxidant
and anti-inflammatory profiles of their diet.
Maybe it’s even their hearts.
Yet another study showing superior VO2 max in vegan athletes,
meaning superior aerobic capacity:
this time they also did echocardiograms,
looking at their hearts in real-time using ultrasound,
and the lower relative wall thickness
and better main ventricle systolic and diastolic function
in the vegans are most likely positive ﬁndings.
Now wait a second. Given the higher VO2 max reached
by the vegan athletes, maybe they were just better trained
than the nonvegan athletes, and that’s why their hearts
looked like they were working better.
However, the weekly training frequency and running distance
were similar in both groups, suggesting benefits
even with the same amount of training.
So, it’s important to educate healthcare professionals;
so they don’t try to discourage a vegan diet
and may even want to consider telling folks implementing
an exercise training program to give it a try.
But you don’t know if it has the same kinds of effects
in nonathletes, until you...put it to the test.
A vegetarian vs. conventional calorie-restricted diet:
the effect on physical fitness in response to aerobic exercise
in patients with type 2 diabetes.
Diabetics were randomized to the same caloric restriction,
the same exercise, but just vegetarian versus nonvegetarian.
They provided all the meals so they could ensure compliance
and closely monitored the exercising.
VO2 max increased by 12 percent in the vegetarian group,
significantly better than in the non-vegetarian group
who didn’t significantly improve at all.
Maximal performance increased by 21 percent in the vegetarian group,
again, significantly better than in the non-vegetarian group
who didn’t significantly improve at all.
In other words, the results indicated that more plant-based diets
led more effectively to improvement in physical ﬁtness
than less plant-based diets,
after the same aerobic exercise program.
Here’s what the graphs look like:
significantly better power output and aerobic capacity
in the group that was randomized to a vegetarian diet.
It seems that those eating vegetarian
were able to better burn off
carbohydrates compared to nonvegetarians,
and had better insulin sensitivity,
both markers of improved metabolic ﬂexibility,
meaning the ability to switch back and forth
between burning sugar and fat.
Besides physiological mechanisms,
there may also be psychological factors.
They observed reduced hunger and reduced feelings of depression
in the vegetarian group which may have given them
a more positive attitude towards exercise.
Here’s the psychological data.
Those randomized to eat vegetarian had a greater improvement
in quality of life and mood.
They felt less constrained, meaning the calorie restriction
didn’t seem as burdensome;
they had less disinhibition,
meaning less tendency to binge and overeat,
along with maybe less feelings of hunger.
Not to mention the superior effects of a vegetarian diet
on body weight, glycemic control, blood lipids,
insulin sensitivity, and oxidative stress.
Wait, better body weight?
I thought they were given the same number of calories.
Yes, both diets were isocaloric, the same calories,
yet just eating meat-free led to significantly more weight loss—
about six pounds more; more waist loss, a slimmer waist;
lower cholesterol, of course; and less superficial fat,
meaning the external jiggly fat;
and most importantly, significantly more visceral fat loss,
the most metabolically dangerous deep belly fat.
Same calories, yet more loss of body fat.
And not surprisingly, better control of their diabetes.
All in addition to leading more effectively
to improvements in physical ﬁtness.