The underlying physiology in the caption is broadly real, but it comes from studies whose protocols do not match the viral instruction.

On calf muscles and glucose. The most cited research behind "calf raises lower blood sugar" is the University of Houston soleus pushup work. When the soleus pushup was tested, the whole-body effects on blood chemistry included a 52% improvement in the excursion of blood glucose and 60% less insulin requirement over three hours after ingesting a glucose drink, and the approach also doubled the normal rate of fat metabolism in the fasting period between meals . Critically, that protocol is not 20 standing raises. In the study, 25 participants did 270 minutes of soleus push-ups with breaks sitting throughout the day , and participants did soleus pushups for 270 minutes a day, that is 4.5 hours of heel raises . The researchers also specify that the movement is deliberately different from ordinary standing heel raises: the soleus pushup activates the soleus muscle differently than when standing or walking . The study measured acute postprandial responses, not a two-week program, and not a bedtime routine.

On circulation. Calf exercise does measurably affect venous return in people with venous disease. A limited exercise program consisting predominantly of toe raises in a six-week home-based program found significant differences in ejection fraction and residual volume fraction , and calf muscle training with compression therapy led to improvements with a large effect size on quality of life, venous return time, pain, edema, and functionality . These were clinical populations with chronic venous insufficiency, usually combined with compression therapy, not healthy people doing 20 reps at bedtime.

On bedtime timing. The strongest evidence for a pre-sleep calf intervention concerns stretching, not raises. In a randomised trial, the experimental group performed stretches of the calf and hamstring muscles nightly, immediately before going to sleep, for six weeks, while the control group performed no specific stretching , conducted in eighty adults aged over 55 with nocturnal leg cramps who were not being treated with quinine , and at six weeks the frequency of nocturnal leg cramps decreased significantly more in the experimental group, mean difference 1.2 cramps per night (95% CI 0.6 to 1.8) . That is stretching over six weeks, not 20 calf raises over two weeks.

On strength and muscle. Calf raise training does build the calf, but in studies using loaded, progressive protocols over months. Standing calf-raise was by far more effective than seated calf-raise for inducing hypertrophy of the gastrocnemius and consequently the whole triceps surae , with reported volume changes of 12.4% versus 1.7% in the lateral gastrocnemius and 9.2% versus 0.6% in the medial gastrocnemius . No trial was found testing 20 unloaded bodyweight raises per night for 14 days.