If you are wondering whether alcohol is ruining your fitness goals, the most important question is: what are your trying to achieve? Are you an athlete training for professional competition, are you trying to loose stubborn body fat, are you training to gain muscle as part of a training plan? All of these questions point us towards a similar answer. Yes, drinking alcohol will impair your fitness goals – but there is a scale.

If you are an athlete training for competition, alcohol is usually off the menu for around six weeks leading up to competition. Dehydration has a severe effect on sporting performance. Even a 1-5 per cent level of dehydration can result in up to 30 per cent reduction is physical performance and put you at risk of injury. Drinking too much alcohol results in the kidneys producing more urine, which is why once you have had a few drinks you can't stop going to the loo. Being properly hydrated is also important for your ability to maintain optimum temperature – or thermoregulation. If you are competing with a hangover and dehydrated you will easily overheat leading to a further loss in performance. When you're metabolising (breaking down) the alcohol, the liver can't produce as much glucose, which results in low blood sugar levels. Glucose is the primary fuel for the brain, resulting in impaired reaction times and decision making ability. These effects can be moderate to severe depending on just how much was consumed.

Trying to loose stubborn body fat? Alcohol is high in sugar, which also means it is high in calories, seven calories per gram to be precise. If your aim is to drop body fat, then a night out on the booze could see you doubling your daily calorie intake. One of the main problems with alcohol is that it is nutritionally void and actually gets in the way of your body's ability to absorb nutrients in food. Coupled with the bad food choices that, for most of us, comes with being drunk, before you know it you have consumed an extra day's calories in one night.

Trying to increase muscle mass? If you think you can use those extra calories as part of a mass gain plan, I'm afraid your body has other ideas. The body doesn't store alcohol, so once it's in the system our body is metabolising it to get it out. All other non-vital processes are put on hold, including adding inches to your biceps. Drinking alcohol also increases the levels of stress hormone, cortisol, in our body. Even though we fall asleep fast and with relative ease, the quality of sleep we have after a night of drinking is poor. REM sleep, where the body heals and grows, is greatly affected. This results in a rise in cortisol and this can reduce levels of our natural growth hormone by up to 70 per cent. The liver also releases another toxin as a by product from the breakdown of alcohol which attacks testosterone, another essential hormone for growth and repair. I recently read that one drink (40 grams of alcohol) has no real effect on testosterone production but three drinks can impair production by 25 per cent and it takes 36 hours to return to normal levels. That is a further one-and-a-half days with low protein synthesis and poor gains. Ouch.

What does this mean for me?

If you are a competitive athlete wanting to achieve your best, then alcohol is a no-go zone. It will effect your performance and recovery.

For those of us who value fitness and even body composition it should be regulated. You can't go hard drinking often and expect to see the results you desire. If you are drinking, choose wisely and try to alternate your drinking with water or even soda water to keep you feeling more full (which might help you avoid the extra eating) and hydrated. Drink plenty of water before you go to sleep and by having less of a hangover the next day you could still make your gym session. Having a hard gym session after drinking excess levels of alcohol can result in muscle strains, pulls and tears due to dehydration. If you do go to the gym the following day, keep the session at light to moderate intensity and be sure to drink plenty of fluids, perhaps even mix half a sports drink to your water.

It's not all bad. Drinking some types of alcohol in moderation can be potentially beneficial. Red wine contains antioxidants and a chemical known as resveratrol that reduces your blood pressure, and consequently protects your cardiovascular system, so the odd glass here or there can be enjoyed guilt free. But before you enjoy the whole bottle, these benefits can also be achieved from eating vegetables – so broccoli still wins, I'm afraid.

Everyday Athlete gym is located in the heart of Glasgow and provides a unique, fun training environment geared towards helping clients achieve their health and fitness goals. Unit 18B 100 Borron Street, Glasgow, G49XG; www.everydayathletegym.com