Freediving is a discipline that tends to encourage participants to maintain a healthy diet, exercise, and abstain from substances that may impair safe underwater performance. However, freedivers can sometimes underestimate how drinking even a few beers the night before diving, and certainly during diving, can impair performance and compromise the mental game.
So, just how does alcohol affect a freediver? The answer may surprise you.
DEHYDRATION: It is not uncommon for a diver to have one or two alcoholic drinks the evening before a dive, which may not result in a significant negative effect if a diver replaces lost fluid with water or a non-caffeinated drink (caffeine causes dehydration). Alcohol is a toxin that pays a visit to every part of the body, leaving dehydration and electrolyte imbalance in its wake. Unaddressed dehydration can cause headaches. If the dehydration is severe, it can take several days for full recovery, leading to appetite loss, which leads to decreased strength and performance, all of which is accompanied by fatigue. Diving while fatigued can mean an increased risk of injury for yourself and/or a dive partner who needs rescuing or finds himself rescuing you.
SLEEP DEPRIVATION: That drink you have the night before your dive will disrupt your sleep cycles, particularly REM sleep. Disturbed sleep or sleep deprivation exacerbates the sedative effects of alcohol the following day. This also causes delayed reaction times and reduced mental acuity and can increase a freediver’s risk of injury to herself, or her partner.
ENERGY DEPLETION: Once onboard, alcohol robs the body of water and nutrients, also emptying you of water soluble vitamins and minerals that your muscles need for performance, giving your system a one-two punch. Concurrently, you impair your body’s ability to produce adenosine triphosphate (ATP), your muscles’ energy source. This loss of ATP results in a lack of energy and a loss of endurance.
ATHLETIC PERFORMANCE: When a freediver’s mammalian dive reflex is activated upon submersion, blood is diverted from the extremities to the core and heart rate decreases. But alcohol changes all that, as it is a peripheral vasodilator, meaning that it causes blood vessels in the skin to open up more than normal. Now, instead of blood being diverted to the core, blood flow fills the expanding peripheral vessels and is diverted away from the body core. This loss of blood saps heat from the more vital area of our body and makes us more prone to hypothermia. Also, alcohol depresses shivering, a symptom designed to warn us of the onset of significant heat loss. And there is another problem. Increased peripheral blood flow causes constriction of the vessels that supply muscles, which results in hypertension, or high blood pressure, which can significantly stress the heart. This may be one of the culprits behind fatal and near-fatal events involving heart attacks in freedivers and scuba divers.
Trying to snag a few fish for your supper? Low amounts of alcohol (0.02-0.05%) can result in a slower reaction time and decreased hand-eye coordination. In low to moderate amounts, alcohol can have a negative effect on grip strength and result in decreased stamina during high-intensity exercise, which could have negative implications in underwater hunting.
HORMONES & MUSCLES: Sleep allows you to rebuild muscle, but alcohol disrupts sleep, preventing the human growth hormone (HGH) from normal muscle building. Alcohol inhibits HGH by as much as 70% and also triggers the productions of a substance in the liver that is toxic to testosterone, which is essential for the development and recovery of muscles.
If you’re working on building muscle, alcohol will sabotage your efforts by pushing aside protein, carbohydrates, and other nutrients, which your muscles need for recovery and growth, as alcohol is always metabolized first. Alcohol has an enormous impact on muscle protein synthesis, reducing it by up to a third.
Alcohol causes a spike in the production of cortisol, the body’s stress hormone. Cortisol impairs thinking, raises blood pressure, decreases bone density and muscle tissue, and the leaves you with the not-so-welcome bonus of increased abdominal fat.
So, here’s the take-away. At the end of the day, divers have to ask themselves, “Can alcohol intake impair my diving abilities or my safety while spearfishing?” The choice to drink before diving is up to each individual, but so is the responsibility to follow freedive safety guidelines, which include looking out for your dive buddy. Bottom line, for optimal performance and safety, freedivers should avoid drinking the night before and the day of diving, until they have stopped diving for the day, and should avoid diving for a few days after drinking to excess. Live to Dive Another Day!