Managing training load is crucial in injury prevention and treatment. A graphic in Tom Goon’s recent blog visualises how training load outweighs all other factors.

Historically we have advised that training loads shouldn’t increase by more than 10% a week. I’m not sure where this number comes from. I’ve got no problem with it, it seems reasonable, and I’ve quoted it hundreds of times.

There’s a 2015 BJSM podcast interview with Tim Gabbett on load management for injury prevention. Specifically Tim talks about this paper:

Spikes in acute workload are associated with increased injury risk in elite cricket fast bowlers 
- Billy T Hulin, Tim J Gabbett, Peter Blanch, Paul Chapman, David Bailey, John W Orchard, 2013.

It is research into fast bowlers, but I think the principles apply just as well to any athlete.  

The authors measured the acute workload of the last 7 days (and call it “fatigue”) and compare that to the chronic workload of the previous 4 weeks (which they call “fitness”).

For runners, if the training is reasonably homogenous, we could most simply measure the workload as the total kms/week.  

Or we could be more accurate and account for a mixed training program that may include a variety of hills / sprints / cross training etc, by giving each session a rate of perceived exertion (RPE) out of 10, and multiply that score by the number of training minutes:

Training load = session RPE x duration (minutes)

This is called a Foster’s Score, and provides a simple method for quantifying training loads from a variety of different training modalities.

The research subtracted the current one-week average from the previous 4-week average and called this number the “training-stress balance”.

A negative training-stress balance increases the risk of injury by 4 times.

So:

[Last 7 days’ session RPE x duration (minutes)] - ([Last 4 weeks’ session RPE x duration (minutes)] / 4) = TRAINING-STRESS BALANCE

Negative balance = 4 times risk of injury

Essentially this formula means you shouldn’t increase your training load by more than 25% a week.

For people that may be more vulnerable to injury I would change the 4-week average to a 6-week average, therefore, bringing the increase in load each week down from 25% to 16%.  

This more cautious group could include: 

• Pre-season training
• Kids going through growth spurts
• Athletes returning from injury
• Known history of over training injuries
• People without any training history
• Novel exercise modality

Summary of: 
FOOTBALL RECOVERY STRATEGIES 
(Grégory Dupont, Mathieu Nédélec, Alan McCall, Serge Berthoin and Nicola A. Maffiuletti, 2015)

• High intensity exercise leads to fatigue.  
  
• Fatigue causes a decline in performance.  
  
• A high percentage of injuries occur late in each half of a game, suggesting that fatigue is a risk factor for injury.

• Combination of central and peripheral factors.
  
• Central fatigue = decreased maximal voluntary muscle contraction and sprinting ability.
  
• Peripheral fatigue = muscle soreness, damage, and inflammation.
  
• Depletion of glycogen stores.
  
• Dehydration.
  
• Muscle damage / stiffness / swelling.
  
• Mental fatigue / motivation.
  
• Jet lag / disrupted body clock / stress / poor sleep.

• Immediately after a match, 20M sprint time, quadriceps strength, and vertical jump height are decreased by about 10%.  
  
• Full recovery can take between two and four days.  
  
• Injury rates are increased when there are less than 6 days between matches.

"When playing two matches per week, the 3-day recovery time between two successive matches may consequently be insufficient to fully recover."

Immediately after a match, players should drink a large volume of fluid (about 150% of the sweat loss) with a high concentration of sodium (about 500 to 700 mg/L of water), flavoured milk, and tart cherry or berry juice. Then, they should eat a meal containing high-glycaemic index carbohydrate and protein within the hour following play.

Rehydration and consumption of carbohydrates and protein are effective techniques for optimising repair of muscle damage.  The addition of sodium at 500-700mg/L promotes fluid retention, stimulates thirst, delays urine production, and increases glucose absorption.  It is recommended to drink a large volume of fluid after the match instead of small quantities gradually.

It is recommended to take 1.2g of carbohydrate per kilogram of bodyweight per hour for up to 5 hours after a match to enable maximum re-synthesis of muscle glycogen stores.

20g of milk protein during the first 2 hours of post-exercise recovery stimulates muscle protein synthesis.  Flavoured milk is an effective beverage for post-exercise recovery. It contains carbohydrate and proteins in similar amounts to those used in studies demonstrating improved post-exercise recovery.

Juices such as tart cherry juice, tomato juice, or berry juice are also recommended to enhancing the recovery process. These juices are loaded with a high antioxidant capacity, which reduce oxidative stress and inflammation.

Alcohol delays recovery as it is a diuretic, increases urine output, impairs sleep, delays the muscular recovery process, and decreases maximal strength.

• Sleep is an essential part of recovery management.
  
• Lost sleep reduces endurance performance, maximal strength, cognitive performance, and the immune system.  
  
• Less than 7 hours sleep per night triples the risk of infections and double the risk of musculoskeletal injuries.
  

• Several meta-analyses confirm the benefits of cold-water immersion for recovery.
  
• The recommended regime of cold-water immersion is: whole-body immersion lasting 10 to 20 minutes at a temperature of 12 to 15°C immediately after the match.
  

• Active recovery performed after a match does not present any benefit for physical performance.
  

• Most studies fail to find a significant beneficial effect of massage for recovery.
  
• Psychological benefits: decreased subjective symptoms of soreness / improved perceptions of recovery.
  

• There is no substantial scientific evidence to support the use of stretching to enhance post-exercise recovery.
  
• Stretching is not clinically worthwhile in reducing muscle soreness in the days following exercise. 
  
• Recovery of physical performance is not improved after stretching.
  

• Meta-analysis on the effects of compression garments on recovery following damaging exercise indicated that the use of compression garments had a moderate effect on recovery of muscle strength, muscle power, creatine kinase and in reducing the severity of delayed onset muscle soreness.  
  
• A placebo effect due to wearing the garments could not be excluded.
  

1. The first step is hydration; the mass of the players should be measured and compared to the pre-match body mass in order to propose the appropriate quantity of fluid to drink (150% of body mass lost). The fluid should contain a combination of water and a large amount of sodium (500 to 700 mg/L of water).
   
2. The second step consists in drinking a tart cherry juice and chocolate milk in order to restore glycogen, to reduce oxidative stress and inflammation, to stimulate muscle repair and to promote quality and quantity of sleep.
   
3. The third step is the cold bath. The players should immerse themselves up to the neck at a temperature between 12 and 15°C for 10 to 20 minutes to accelerate the recovery process.
   
4. The fourth step is to wear a compression garment until bedtime.
   
5. The fifth step is to eat a meal high in carbohydrate with a high-glycaemic index and protein within 1 hour after the match (for example soup, well-cooked white pasta or mashed potatoes, chicken or fish, yogurts or cake).
   
6. The final step is to have a good night’s sleep.
   

WATCH DR DUPONT'S PRESENTATION AT ASPETAR'S POST-EXERCISE RECOVERY CONFERENCE:

​I’d guess that most people feel guilty about not stretching enough.

Interestingly, health professionals have changed our tune about the importance of stretching.  Research over the last 15 years has suggested static stretching is not as beneficial as was once thought.  I’ve been having conversations about the reasons to stretch (or not) for at least the last 15 years, but the current science on stretching just isn’t catching on.  

So, what do we know?…
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No.  There is a lot of evidence that stretching does not reduce the risk of injury.  This systematic review and meta-analysis of randomised controlled trials found stretching does not prevent injuries, whether done before or after training.  This randomised controlled trial, and this systematic review concluded stretching before exercising only reduces the risk of injury by less than 1%.  

​Therefore, in practical terms the average athlete would need to stretch for 23 years to prevent one injury.  Definitely not worth it.
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No.  A systematic review concluded that stretching before or after exercising does not confer protection from muscle soreness (ref).  Stretching was found to reduce muscle soreness by a trivially small amount - less than 2%.

​No.  Stretching for the amount of time that most people would hold their stretches, does not make any actual difference to flexibility.  The mechanisms of stretching have been extensively studied.  There is moderate evidence from a systematic review that stretching can increase flexibility (ref). However, to achieve an actual improvement in muscle compliance we know the total duration of stretching needs to be at least five minutes per muscle group (ref).  Therefore to stretch hamstrings, quads, and calves, both left and right, as part of a warm up before sport, it should take at least 30 minutes - which is practically impossible as part of a warm up.  We know the one or two, thirty second stretches the majority of athletes would perform during their warm up are just not enough to actually improve their flexibility (ref).
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What people find most surprising about static stretching is it impairs subsequent performance (ref).

A substantial body of research has shown that sustained static stretching acutely decreases muscle strength and power (ref).  Stretching before an endurance event lowers endurance performance and increases the energy cost of running (ref).  Cycling efficiency and time to exhaustion are reduced after static stretching (ref).

Pretty much any measure of performance is made worse by stretching.  Static stretching impairs: 

• strength
• maximal  voluntary contraction
• isometric force
• isokinetic torque
• one repetition maximum lifts
• power
• vertical jump
• sprint times
• running economy
• agility
• balance

A comprehensive review (ref) from 2011 concludes:

​Obviously, I’ve been talking about sustained, static stretching.  It has been shown that there is no stretch-induced strength loss with dynamic stretching (ref).  However, the efficacy of dynamic stretching for increasing flexibility is yet to be determined (ref).
​

I do get people to stretch if there’s a specific pathology that needs treating.  And you do need to stretch if you need flexibility to achieve certain positions in your sporting performance (hurdlers / gymnasts / divers, etc).
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If you’re happy with your stretching routine, keep doing it.  If you think it feels good to stretch after exercise then there’s no harm.  But I definitely wouldn’t recommend stretching at the expense of other techniques that are proven to aid recovery.