Exercise, while very safe, presents slight risks, particularly in new exercisers. Circulation reminds us:
Cardiovascular
- During exercise, there is a transient increase in the risk of having a cardiac-related complication (for example, a heart attack or serious heart rhythm disorder).
- However, this risk is extremely small. For adults without heart disease, the risk of a cardiac event or complication ranges between 1 in 400 000–800 000 hours of exercise. For patients with existing heart disease, an event can occur an average of once in 62 000 hours.
- The risk of a cardiac event is significantly lower among regular exercisers. Evidence suggests sedentary people’s risk is nearly 50 times higher than the risk for a person who exercises about 5 times per week.
- Individuals who exercise regularly are much less likely to experience a problem during exercise.
- The majority of heart attacks (approximately 90%) occur in the resting state, not during physical exercise
- Another report states that vigorous physical activity acutely increases the risk of cardiovascular events among young individuals and adults with both occult and diagnosed heart disease
Tripping, Falling
- Tripping and falling can happen at any time.
- Some sports are inherently riskier than others
- New exercisers may be at somewhat higher risk of tripping and falling or other injuries, particularly if tired and not familiar with the movement patterns
Musculoskeletal Injuries
- Doing too much too soon can cause an injuries
- Delayed-Onset Muscle Soreness (DOMS) is not really considered to be an injury and is expected in new exercisers and whenever exercise intensity in a muscle group is stepped up.
- Appropriate regular stretching, notably after workouts, will also help keeping the body balanced and injury-free
Overtraining
- Too much, too frequent exercise and not enough recovery for the individual can lead to the dreaded overtraining
- Most people realise they are over-trained well after everyone else has noticed: be smart, train smart and avoid damaging your body (particularly hormones) in the first place!
- The type of training should also match the individual and their current health and fitness levels, as well as preferences
TIMING – Morning Versus Afternoon Exercise
Adults
Acute Myocardial Infarction (AMI) and Sudden Cardiac Death (SCD) in adults are more frequent in the early morning hours (ahajournals).
Adult males with obesity or diabetes who exercised in the morning had the highest risk of developing CHD. See: Diabetes and Exercise Timing
This has prompted speculation as to whether vigorous exercise should be best restricted to afternoon hours in individuals at increased risk.
Young Athletes
- Among young athletes, sudden death and cardiac arrest among young athletes occur primarily in the afternoon and early evening and are associated with training and competition.
- Among young nonathlete patients with hypertrophic cardiomyopathy, sudden death is more frequent in the early waking hours, much like CHD
Adults with Cardiovascular Disease
- The limited data suggests the time of day had little or no influence on the rate of cardiovascular complications during exercise-based cardiac rehabilitation.
- The intensity of this exercise is likely well controlled and appropriate long warmups and cool downs are carried out to avoid risk of adverse cardiovascular events.
- Given the likely benefits of exercise in reducing cardiovascular events and the low overall rate of exercise-related events, it is probably more important that individuals exercise regularly at a convenient time of day than at a specific time of day.
While more research is needed, it is good information especially if you dislike morning exercise! It means you have good reasons to exercise at some other time of the day you prefer.
REFERENCES
https://www.ahajournals.org/doi/full/10.1161/circulationaha.107.181485
https://www.ahajournals.org/doi/full/10.1161/01.CIR.0000048890.59383.8D