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Just How Tough is Tennis?

Strenua — Tue, 06 Jul 2010 01:13:22 +0000

2008 US Open Final - Andy Murray and Roger Federer

Following the epic match between John Isner and Nicolas Mahut at the beginning of Wimbledon 2010, Andy Murray tweeted ‘This is why tennis is one of the toughest sports in the world, this will never ever be matched again’.

After watching some of the world’s elite footballers play so disappointingly during the World Cup, supposedly their sports most prestigious competition, Murray’s point is justified. Football is a team competition; players can be rested during matches, be substituted when injured and even miss matches by suspensions. Even the winning team will have only played 7 matches of 90mins (with possible extra time of 30minutes) over a period of 4 weeks.

In comparison Isner and Mahut’s single match took a record breaking 11 hours and five minutes, with the final fifth set alone taking eight-hours 11-minutes. In total 980 points including 215 aces were played over 183 games, the final score at 6–4, 3–6, 6–7(9–7), 7–6(7–3), 70–68. However, when you see slightly overweight, middle aged people inspired by Wimbledon fortnight, playing tennis on your local courts tennis doesn’t seem so demanding.

So why should tennis be considered a tough sport?

Whilst a knock about on the beach or the local park does not seem that strenuous, professional competitive tennis requires a combination of physiological and unpredictable variables. Each match depends on adapting to a number of factors:

Match duration (3 or 5 sets)
Weather
Opponent
Surface
Level of play

But within each match or indeed between each point there are also a number of variables that need to be considered:

The length of the point
Playing style of both players
Velocity of shot
Shot selections

Tennis players need to train specifically for their sport and playing style. During high level matches points have an average length of between 3 seconds to around 15 seconds on some of the faster surfaces such as grass and indoor. However the total playing time is only between 20-30% of the total match time and varies considerably between when the player in control of a rally is an attacking player who hits the net hard then consistently comes to the net, a whole court player, or a baseline player.

Is Tennis an Aerobic or Anaerobic Sport?

Tennis requires short explosive bursts of energy repeated hundreds of times per match which as we have seen can be of a long duration. This requires players to be trained anaerobically for performance and aerobically to aid recovery during and after play.

Maximum oxygen uptake (VO₂max) is used as a marker of aerobic capacity. Generally VO₂max and heart rate increases as the game progresses, decreasing during rest periods and end changes. VO₂max in competitive high level tennis players has been reported to be greater than 50ml/kg/min classifying tennis players as highly aerobically trained with aggressive attacking players having a lower VO₂max than baseline players.

The mean heart rate in trained players aged 20–30 years has reported to be between the ranges of 140–160 beats/min during singles matches. The long duration and moderate mean heart rate during a match suggests that tennis an aerobic sport.

However the explosive nature of the serve and ground strokes, along with rapid changes of direction requires a tennis player to have a high anaerobic capacity. Together with the need for a high percentage of fast twitch muscles tennis could be considered more as a predominantly anaerobic activity, needing high levels of aerobic condition to avoid fatigue and aid recovery between points.

Strength, Speed and Agility

In addition to stamina tennis players need fast reaction times to respond to every shot from the opponent. They are required to move not only forwards and backwards but also sideway and diagonally, so need to be agile, able to accelerate and move at a maximum speed.

Strength training is also important not only in muscles and joints for performance but also to reduce injuries. As well as the expected required strength in the shoulder and upper arm, tennis players require a firm wrist to direct the racket head under high speeds. Players also require a deal of flexibility, not only through reaching for or playing a racket shot but also when throwing the ball when serving.

There is no doubt that training as a competitive tennis player is demanding. You need to be both anaerobic and aerobically fit, have stamina, strength, speed, flexibility and agility, as well as being mentally aware to respond to your opponent’s shots. There are however other professional sports which could arguably also be considered some of the toughest in the world.

Triathletes competing at Ironman distances for example, may argue that a 2.4-mile (3.86 km) swim, a 112-mile (180.25 km) bike and a marathon (26 miles 385 yards, 42.195 km) run, raced in that order and without a break, is also quite tough. As might the cyclists competing in the Tour de France covering around 3,600 kilometres (2,200 mi) through 21 stages over 3 weeks. But considering it took Rafael Nadal 17 and half playing hours, over the course of two week tournament to win 2010 Wimbledon championship I will concede to Andy Murray that professional competitive ‘tennis is one of the toughest sports in the world.’

Can Creatine and High-Intensity Interval Training Improve Cardiorespiratory Fitness?

Strenua — Wed, 30 Dec 2009 11:14:22 +0000

Creatine is a popular supplement used for increasing muscle mass and also recovery from exercise induced muscle damage. Now a study has looked at the effect of creatine supplementation and high-intensity interval training (HITT) on cardiorespiratory fitness.

Phosphocreatine is a high-energy storage molecule found within skeletal muscle. During intense exercise, phosphocreatine provides immediate replenishment of ATP (Adenosine-5′-triphosphate), which transports chemical energy from within cells for metabolic processes.

Traditional endurance training induces physiological adaptations such as improved aerobic capacity, along with a reduction in glycogen utilization and lactate accumulation. HITT has been shown to be an efficient way to produce similar effects.

Multiple HIIT bouts are designed to deplete phosphocreatine stores in the working skeletal muscle, and so reducing power output.

It takes more than six minutes to fully recover phospho-creatine stores after exercise-induced depletion. Therefore, if recovery intervals during HIIT bouts are less than six minutes, phosphocreatine may not be fully replenished, leading to a reduced performance.

Supplementing with creatine has been demonstrated to effectively increase muscle phosphocreatine stores. Specifically, one study showed a 20% increase in muscle creatine with ingestion of 20 g of creatine per day for just 5 days.

The purpose of the study published in the Journal of the International Society of Sports Nutrition was to determine the effects of high-intensity interval training and creatine supplementation on cardiorespiratory fitness and endurance performance.

The subjects were 43 college-aged men who typically performed 1-5 hours of exercise per week. None had taken sports supplements, including any form of creatine, in the three months prior to the beginning of the study.

Participants were randomly assigned to a creatine or a placebo group and supplemented for 30 days at a dose of 10 g per training day, taken in two doses – one dose 30 minutes prior to and one dose immediately following training.

Creatine group consumed 5 g of creatine citrate mixed with 15 g dextrose
Placebo group consumed 20 g of dextrose

A control group, consumed no supplements nor completed the high-intensity interval training, and instead only completed the testing measurements.

Participants performed HIIT five days per week, for six weeks at progressively increasing workloads, determined as a percentage of the participant’s baseline VO_2PEAKmax workload. Training increased in intensity each session beginning at 90% of their VO_2PEAKmax workload and progressing up to 120% of their VO_2PEAKmax workload.

Each training session began with a five-minute warm up, followed by a protocol of five sets of two-minute exercise bouts, with one minute of passive rest in between exercise bouts.

A maximal graded exercise test on a cycle ergometer was used to determine:

maximal oxygen consumption (VO_2PEAK)
maximum heart rate (HRmax).
total work done (TWD)
time to exhaustion (VO_2PEAKTTE)
ventilatory threshold (VT), this is the point during graded exercise in which venitilation increases disproportionately to oxygen uptake.

Endurance performance is commonly assessed using a measure of aerobic capacity. While the HIIT program was effective in improving maximal oxygen consumptionby 9%, creatine supplementation had no further influence on aerobic capacity. Ventilatory Threshold (VT) is another useful predictor of endurance performance as an indicator of the ability of the cardiovascular system to adequately supply oxygen to the working muscles. Performing exercise at intensities greater than VT often result in an inadequate supply of oxygen to the working muscles, quickly leading to fatigue.

If VT can be improved it could increase the time to exhaustion, reduce fatigue, and may enhance the efficiency of the body to supply oxygen to the working muscles.

However, when measuring VT in this study, significant improvements were only observed in the creatine group (16%), although the placebo group demonstrated a trend for improved VT (10%).

The researchers from University of Oklahoma found that HITT is an effective way to improve maximal endurance performance. The study also demonstrated an improvement to time to exhaustion with HIIT. However, whilst adding the use of creatine did improved ventilatory threshold, it did not increase total work done.

Previous studies have shown improvements in TWD after creatine supplementation which included a loading phase (20 g/d for 5-7 days). A loading phase was not used in the current study, so it may be possible that muscle phosphocreatine levels were not increased enough to aid in improving TWD.

The researchers did suggest that it is possibile that any benefits of low-dose creatine supplementation were masked by the effectiveness of HIIT alone.

Should endurance athletes take creatine supplements?

Strenua — Wed, 26 Aug 2009 12:11:13 +0000

Creatine has become a popular nutritional supplement among athletes and is often taken as supplement by people who want to gain muscle mass, such as for body building, but there is increasingly evidence that it may also help in recovering from exercise induced muscle damage.

Creatine is a natural occurring substance that helps supply energy to muscles. Half of stored creatine comes from food, mainly fresh meat, so as a vegetarian I am likely to have lower levels of muscle creatine. The enzyme creatine kinase (CK) is responsible for the reversible reaction whereby creatine is converted along with ATP to create phosphocreatine and ADP to generate energy.

Whilst creatine has been shown to be beneficial for short high intensity exercises such as weight lifting, it has not shown to have any benefit to endurance activity performance. In fact as creatine is also responsible for weight gain of around 1kg when taking the ‘loading dose’ of 20g a day it may even slow an endurance athlete down without providing any benefit to performance. A study has however, looked at the benefits of creatine on muscle recovery following endurance running

In the study published in Life Sciences journal, subjects were given 4 doses a day of 5g of creatine and 15g of maltodextrine, while the control group received just maltodextrine for 5 days, before a 30km race. The runners were experienced marathon runners with personal best (PB) times of 2.5 -3 hours.

Blood CK levels can be raised from damage of the muscle tissue as a result of intense training and it is often used as a marker of muscle injury. In this study by the University of São Paulo, it was found that athletes from the control group had increased CK levels suggesting a high level of cell injury and inflammation while Creatine supplementation reduced these increases.

In short term studies of less than two weeks there have not been reported side effects of taking creatine supplements. Dr Santos, the papers author reported that ‘the runners finished in times equivalent to their PB, without any side effects such as cramping, dehydration or diarrhoea whilst taking the supplements or during the race.’ However athletes who have taken it long term have reported muscle cramping and kidney damage.

In 2007 International Society of Sports Nutrition published its position on the use of creatine supplementation and exercise. Amongst some of their statements they concluded that ‘there is no scientific evidence that the short- or long-term use of creatine monohydrate has any detrimental effects on otherwise healthy individuals. Creatine monohydrate supplementation is not only safe, but possibly beneficial in regard to preventing injury and/or management of select medical conditions when taken within recommended guidelines.’

Recovering from endurance exercise is important for the long distance runner, but is it worth taking creatine supplements in the days leading up to a marathon to prevent damage and aid recovery. Is it worth possible muscle cramps and other side effects during the race after all you don’t know how your individual body will react?

What’s your view? Are you an endurance athlete who has tried creatine supplements, or do you think we shouldn’t use any type of ergogenic aids? Let us know you experiences or opinions.

Also read related post Can creatine supplements enhance muscle recovery?

Cereal and non-fat milk support muscle recovery after endurance exercise

Strenua — Tue, 09 Jun 2009 22:28:38 +0000

It’s something I know I’m guilty of. Come back from a long run, get in the bath and forget all about eating and refuelling.

Endurance exercise affects skeletal muscle by reducing energy stores and increasing muscle protein breakdown. So after exercise it’s important to refuel and replace the bodies main source of stored energy, glycogen. During endurance exercise glycogen stored in skeletal muscle is reduced which can limit exercise duration and intensity. Therefore, it is important to replenishing these energy stores before your next training session or competition.

In addition, muscle protein breakdown is continuously occurring, even at rest, releasing amino acids to be used for protein synthesis. However, protein synthesis is stimulated by exercise and muscle protein breakdown is increased. So it’s important that consumption of food must offset breakdown to create a positive net muscle protein balance.

Taking these two facts into account suggests that the ideal recovery food must contain both carbohydrate and protein to provide substrate for glycogen synthesis and achieve net protein balance. But what’s the best fuel to use?

Commercial carbohydrate-electrolyte sports drinks are available for post exercise recovery, but how do they compare with eating regular food. A group of researchers from the University Texas have compared the effects of ingesting regular cereal and non-fat milk, with drinking carbohydrate-electrolyte sports drink immediately following endurance exercise, investigating muscle glycogen synthesis and the regulation of proteins controlling protein synthesis.

Whilst many studies use untrained subjects or exercise to exhaustion Dr Kammer’s study a more realistic training scenario. The study published in Journal of the International Society of Sports Nutrition involved trained cyclists and triathletes who completed 2 hours of cycling at 60-65% of their predetermined VO₂MAX (this is the maximum volume of oxygen that can be used during one minute of maximal exhaustive exercise).

Immediately after exercise the subjects consumed either a drink (containing 78.5 g carbohydrate) or cereal (77 g carbohydrate, 19.5 g protein and 2.7 g fat). The researchers found that after 60 min following refuelling with either the drink or cereal:

blood glucose levels was similar between both drink and cereal;
significant changes did occur in glycogen levels following both methods of refuelling;
glycogen and muscle proteins were not different between treatments.

BUT

after cereal blood insulin levels was significantly higher;
after cereal blood lactate was significantly lower;
only cereal significantly affected glycogen synthase.

The researchers were able to conclude that while the drink provided carbohydrate, only the cereal and milk provided carbohydrate and essential amino acids necessary to support both glycogen and protein synthesis. This is due to the cereal option also providing easily digestible and quality protein in the milk. The benefits of the findings to the everyday athlete is that cereal and non-fat milk provide a less expensive whole food option as compared to sports drinks.

Whilst Dr Kammer and colleagues now suggest cereal and non-fat milk as a potential option for athletes who refuel at home, the down side was that to eat the necessary amounts of carbohydrates required consuming the equivalent of two potions according to the recommended sizes on the box.

So now we know what to eat, I just need to schedule time for it straight after training, before I head for the bath.

Chill as you rehydrate to improve endurance

Strenua — Tue, 02 Jun 2009 11:15:44 +0000

With summer arriving and temperatures rising, it’s even more important than ever that you take out your drinks bottles when you are training or competing.

We all are aware that dehydration through sweating can compromise athletic performance. Evaporating sweat from the skin surface is the body’s way of regulating our core body temperature, essential whilst exercising in this summer heat. Unfortunately if our sweat loss exceeds fluid intake we can become dehydrated, this is increased if you are involved in intense exercise, in a hot, humid environment. Dehydration of just 1-2% of body weight begins to compromise physiological function and negatively influence performance. However you should drink according to individual needs and not on published recommendations as hyperhydration can be as dangerous as dehydration. I shall write more about how to determine your own personal fluid intake in a later article.

You probably have your own personal favourite drink when training or competing, whether it’s a manufactured sports drink, your home made recipe, or just plain water. But have you considered the effect the temperature of the drink may have on your performance?

In the journal Medicine & Science in Sports & Exercise,researchers from Loughborough University investigated the effect of drink temperature on cycling capacity in the heat. The two groups of males cycled to exhaustion in hot (35^oC) and humid (60%) environments. The subjects drank three 300-mL volumes of either a cold (4^oC) or a warm (37^oC) drink during 30 mins of seated rest before exercise and 100 mL of the same drink every 10 mins during exercise.

They found that compared to the warm drink, drinking cold drink resulted in:

Longer exercise time – (64mins with cold 52 mins with warm).
Lower mean skin temperature after 20 mins during exercise.
Lower heart rate before exercise and for the first 35 min of exercise.
Reduced sweat rate (1.22 L/hr for the cold and 1.40 L/ hr with the warm drink).
Lower perceived exertion during exercise.
There was no effect of drink temperature on mean skin temperature at rest.
Overall improved endurance capacity of around 23%.

Author of the paper, Dr Jason Lee, concluded that compared with a drink at 37^oC, the ingestion of a cold drink before and during exercise in the heat reduces physiological strain during exercise due to reduced heat accumulation.

Obviously keeping your drink at 4^oC isn’t practical if you have to carry it as you run or cycle, but how about keeping your drink in the fridge before you start exercising. During exercise you can make sure it’s kept in the shade or a bucket of iced water, if you are playing sport in a fixed location. I also like to put my drink in the freezer before I go out. Not enough for the drink to freeze solid but enough to allow a few ice crystals to form to keep it chilled for longer. If I can make my endurance capacity increase by 23% just through the temperature of my drink, I think this is one suggestion I’m going to try to incorporate in my running this summer.

Do you have any suggestions how to keep you drink colder, for longer whilst exercising during the summer? If so let us know.