Tapering

Leading into a major competition many athletes will attempt to taper, so that they can perform their best on the day of the competition. While some research has been done into tapering it is still as much an art as it is a science, and there are lots of questions about tapering that still remain unanswered. A combination of existing research and anecdotal evidence from many top coaches will help you prepare an effective taper to suit your competition level. 

Designing Your Taper

 During high volume training, like that used by many rowers, training adaptations are often masked by a gradual accumulation of fatigue. Tapering is designed to give the athletes the chance to fully recover form their training so that the performance improvements can show through. A well designed taper can increase performance by up to 3-4%.

 

Not every athlete will benefit form a taper. Before you get too excited about tapering you should consider your need for a taper. Novices, with limited training experience will not see much improvement from a taper. Novice athletes will probably benefit more from a continued higher volume of training leading into a race followed by 1-2 days off just prior to the race. This is because most novices haven’t mastered the technical skills of their sport to the point that they are going to be limited by their fitness. A higher volume of skill and tactical work leading into a race will probably pay bigger performance dividends than a taper.

 

Athletes who are training less than six hours per week will not benefit much from a true taper. These athletes can take a day or two off immediately before a race and be sufficiently recovered to race at their best. If you fall in to this category you may want to plan a short sprint training session about mid week before the competition, focusing on starts and sprints of up to 500m. This would be the last training day of the week before taking two days off prior to the race.

 

Duration

For those who are training more than 6 hours per week and are not novices your taper needs to be planned according to your work volume. Table 1 gives some guidelines for the duration of a taper depending on how many hours per week you train.

 Table 1: Duration of taper

Training Hours/Week	Duration of Taper
6-10	7 days
10-15	14 days
15+	21-30 days

 

During a taper your volume of training will progressively decrease by about 70%. In other words if you are normally training 10 hours per week and will be doing a 7 day taper you will only train about 3 hours that week. Keep in mind that the decrease in volume is not accomplished in one cut; it is progressive. If you are doing a longer taper you may want to consider the following progression (table 2)

 

Table 2: Percentage decreases in volume while tapering

Normal Volume	Taper Week 1 hours	Taper Week 2 hours	Taper Week 3 hours
6-10	Decrease by 70%	—–	—–
10-15	Decrease by 45%	Decrease by 70%
15+	Decrease by 30%	Decrease by 50 %	Decrease by 70%

 

 Frequency

 The number of workouts per week does not decrease during a taper. The decrease in volume is accomplished by decreasing the duration of each workout. The focus of a taper is recovery and regeneration, it is easier to recover from a short workout because it does not full deplete energy stores. Longer less frequent sessions dose not allow the athlete to full recover or adapt to the training they are doing, particularly since the intensity is increasing during the taper.

 

Intensity

  Intensity increase throughout the taper as the training volume decreases. Steady state pieces are gradually replaced with higher intensity intervals, short sprints, and starts. By the final week almost all the training will be done at or above anaerobic threshold. A final week of a taper may look something like this

 

Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
40 minutes easy steady state	4 x 5min  above AT, 10 minutes rest between	5 x 2 min, 30 minutes easy steady state	OFF	4-6 x 250 m sprints with 10 minute easy between	4 x 2 min at race pace, 5 minutes between	RACE

 

The sprint work in the last two days is as much a psychological factor as it is a physiological factor. Sprints will give the athlete feelings of speed, power, and confidence that they can take with them into race day. This means it is important to have a good final training session, that leaves the athletes energized not fatigued. Ideally this final training day is done on the race course so that the crew has time to familiarize themselves with the course.

 

This sample will obviously change depending on the duration of a race and travel requirements.

 

Special Considerations During a Taper

 

A taper should be practiced at least once before the major competition of the year. It is not necessary to practice a full 21 day taper but the final week must be tried at least once, during a less important competition. This will give you the opportunity to adjust the taper to your individual needs and experiment with different combinations of intervals and sprints during the final week.

 

Athletes trying to keep their weight down need to pay careful attention to their weight during a taper. One of the adaptations to a taper is an increase in muscle glycogen storage. For every gram of glycogen stored in the muscle 3-4 grams of water are stored. This can result in a large increase in weight in a relatively short period of time. A certain amount of weight gain may be necessary if the athlete is to see performance improvements as a result of the taper. The increased glycogen storage not only feeds the muscles during training but it is used as an energy source for other adaptations to occur. Lightweight rowers have to carefully balance the amount of glycogen supercompensation that will improve performance with the amount of weight they can gain.

 

A Note for Coaches

 

The taper period can be a time of high psychological stress for both the coach and athlete. Coaches tend to worry about the training that was done during the season, the duration of the taper, and many other things that arise prior to a major competition. It is important at this time of the year that the coach projects confidence both in what has been done during the season and in the taper. If the coach is openly worried about the athlete’s preparation or starts making changes to a planned taper the athletes may begin to question their preparedness and ability to win.

 

Athletes handle the decreased training volume differently. Many athletes will enjoy the feelings of speed, power and renewed energy. Others have a tough time dealing with the decrease in volume. They worry about detraining and don’t know how to cope with the extra time as a result of the decreased volume. A coach needs to be aware of the responses of each athlete, and be prepared to deal with the worriers.

Strength Goals for Masters Rowers

This is the second part of the series of articles that started with Strength Goals for Competitve Rowers. You should refer back to that article for the background information on the development of  strength goals for rowers. The four points at the end of the article apply to masters as well as younger rowers.

 Strength is important for rowers. It is even more important for Masters rowers. As I discussed in a previous article the start, where strength is most important, is a much larger part of a 1000 m race than a 2000 m race. You don’t have the time to make up the distance you could lose if you aren’t strong off the start.

 The strength factor tables below are based on the ideal strength level of younger club rowers and corrected for age. This was done to accommodate the greatest number of masters rowers possible. Basing these strength goals on international competitors would not create a realistic picture of the strength level a masters rower needs to be competitive against their peers.

 

 Men

 

	35-39	40-44	45-49	50-54	55-59	60-64	65-69	70+
Squat	1.37	1.30	1.2	1.15	1.03	0.95	0.82	0.60
Deadlift	1.37	1.3	1.2	1.15	1.03	0.95	0.82	0.60
Bench Pull	1.02	0.98	0.94	0.88	0.78	0.71	0.62	0.45

 

 Women 

  

	35-39	40-44	45-49	50-54	55-59	60-64	65-69	70+
Squat	1.22	1.16	1.08	1.00	0.91	0.80	0.72	0.50
Deadlift	1.22	1.16	1.08	1.00	0.91	0.80	0.72	0.50
Bench Pull	0.93	0.88	0.82	0.76	0.69	0.60	0.55	0.38

 

Using the Tables

 To use the table take your body weight and multiply it by the appropriate factor. If  you were a 200 lb. 53 year old male rower you should be able to bench pull 176 lbs. one time (200 lb. Bodyweight  x 0.88 strength factor = 176). If you currently are able to meet these goals you can focus your training on other areas. If you can’t meet these goals strength may be one of the things holding back your performance.

 

Strength Concepts for Masters

 

 Balanced Approach

 While there are only strength factors for three exercises it doesn’t mean these are the only three exercises that you do.  Rowing strength exercises can be broken into two major categories, Specific and General. I will provide a brief outline of these categories in this article and provide a more detailed look at the exercises in the near future.

 Specific exercises are those that are intended to strengthen all or part of the rowing stroke or that improve explosive power that can be converted to boat speed. Specific exercises can include traditional weight room exercises and rowing simulation exercises like a can or bungee row.  Specific weight room exercises include cleans, deadlift, squats, front squats, bench pull, back extensions and seated row. It is tempting to build a program using only specific exercises. After all, these are the exercises that simulate part of the rowing stroke. Specific exercises will only improve rowing performance when they are balanced with the proper mix of general exercises.

 General exercises help prevent injury and develop stability and balance. Muscle imbalances, either bilateral (differences between right and left side) or agonist/antagonist (muscles that are on opposite sides of a joint), have been implicated in the development of injury. Several studies have found  that a muscle imbalance of greater than 10% increases the risk of injury by 20 times. Other researchers found that all their subjects with a strength imbalance of 25% or more developed an injury in the weaker leg.

 Muscle imbalances are a serious problem for rowers. Sweep rowing in particular causes the oarside leg to become stronger and non-oarside trunk muscles to become over developed. The quads and hip flexors become strong and inflexible while the glutes and hamstrings remain relatively weak. The same thing happens with the back and abs.

 The number of general exercises that can be done is almost limitless. Stability ball exercises, step ups, split squats, snatch squats, bench press, arm curls, tricep extensions, rotator cuff exercises, trunk rotations and leg curls are some of my favorites.

  It is important to include a specific and general exercises in a program. Choose exercise  for the muscles on both the front and back of the body. Always make sure to train both the right and left sides equally. If you are strength training 3-4 times per week you don’t need any more than six exercises per training session. Select two specific and four general exercises.

 

Machines vs. Free Weights

 From the e-mail I have received I get the impression that many Masters us machines for strength training.  I am not a fan of most strength machines for rowers. Some like a lat pulldown machine, seated row or leg curl have their place but they should not make up the majority of a program. The movement path is fixed in machines this means that the muscles don’t have to work to stabilize the weight during exercise. The small deeper layers of muscle that provide balance and stability in the boat never get trained with machines. These small muscles become the weak link in your rowing strength and prevent you from transferring the strength you develop in the weight room to the water. In addition, most machines don’t allow the right and left to work independently. The stronger side will often take more of the load, leading to greater and greater muscle imbalances and increasing your risk of developing an injury.

 I understand that many people use machines because they are easier to use than free weights and they may not know the right way to do a free weight exercise. Others have been given machine exercises by the trainer at their local gym. It is in your best interest as a rower to take the time to learn how to do at least some free weight exercises. The balance, stability, and athleticism used in free weight training will have a greater impact on your rowing performance and injury prevention than any machine.

 

Strength Train All Year

 If you strength train during the winter months and then stop once you get back on water any strength gains you’ve made will be lost within 6-8 weeks. This may be fine if you are rowing for fun and fitness but if you are competing and trying to improve your race times you need to keep your strength during the season. I have always found it a little strange that many rowers are their strongest on the first day they get on water and weakest for their final, and often most important, race of the year. You will need at least 16 weeks of winter strength training to see appreciable gains that will transfer to rowing performance. Once you get back on water you will need 1-2 days a week of strength maintenance training. If you notice the weight you are using during the maintenance training starts to decrease you are losing strength and will need to increase the amount of strength work for 2-3 weeks or until strength returns to normal.

Strength Goals for Competitive Rowers

The majority of rowers use some form of resistance training in their preparation for the rowing season. While strength is obviously very important for a competitive rower how strong does a rower have to be? Does is really make any difference in rowing performance if you increase the weight you can squat from 500 lbs. to 550 lbs.?

 

Every sport requires a certain level of strength to achieve optimal performance. Increasing strength beyond these levels does not necessarily improve performance and in some instances can be detrimental to performance. Once the ideal level of strength has been achieved the time needed to increase beyond this point could be better spent training something else i.e. rowing technique, aerobic fitness, flexibility, or anaerobic fitness.

 

How Much Strength do Rowers Need?

 There are several ways to determine the strength demands of a sport. A biomechanical analysis of the forces generated on the foot stretchers, oar lock, or at the blade can provide good information on how much force is developed with each stroke. Elite rowers generate their highest forces on the first stroke of a race. These forces have been found to reach 1352 N, which is roughly equal to 135 kg, for men and 1019 N or 102 kg for women. Back in 1975, research on the East German National team indicated that the minimum level of rowing strength required for international competition was 133 kg. With the increases in boat speed and changes in oar technology this is undoubtedly higher today.

 A second method for determining strength goals is to base them on the strength levels of elite competitors. Presumably, if a competitor is medalling at the Olympics or World Championships they are strong enough to be successful. This doesn’t hold true all the time because of differences in technical efficiency and aerobic fitness but it is a good starting point. In order to study maximal force generation at the catch Secher developed an isometric apparatus that was adjustable so as to suit individual rowing positions. Using Dutch Olympic, national, and club level rowers it was found that international rowers on average generated 204 kg of force. National level rowers generated 183 kg of force and club rowers generated 162 kg of force. Using other non-specific rowing tests – isometric arm pull, back extension, trunk flexion and leg extension – on the same groups of athletes, it was found that the higher the competition level of the rower the greater the strength in all tests.

 The use of non rowing tests of strength has it’s pros and cons. Force application in a boat is technically different than it is in a leg press or squat. While these tests are very good for determining if the muscles are strong enough to do the job they don’t necessarily reflect someone’s boat moving ability. Weight lifting tests do have the advantage of being low tech, they don’t require computer links to strain gauges or force plates, and easy to administer. Concept II has developed a machine called the Dyno which works on the same air resistance principals as the erg but can be used for strength training and testing. This is a very well made machine and in time will probably become a standard tool for strength testing for rowers. Unfortunately, because it has only been on the market for a couple of years I can’t provide any strength norms for it yet.

 

Strength and Body weight

 Strength can be classified as either absolute or relative. Absolute strength represents the maximum amount of weight that can be lifted one time. Larger people tend to have higher absolute strength than smaller people because they carry more muscle mass. Relative strength is the maximum amount of weight that can be lifted one time in relation to bodyweight. Relative strength is of more importance to a rower than absolute strength. The amount of weight in a boat affects the drag through the water. Increasing absolute strength is of no benefit if the weight gain offsets the strength gain by increase resistance through the water. Increasing relative strength makes it easier to accelerate the boat with each stroke because strength has increased without increasing the drag. It is because of the importance of relative strength that the strength goals presented here are expressed as percentages of bodyweight.

 

Strength Goals

 The table of goals below have been developed from the data I have collected during my consultation with rowers from novice high school rowers to Olympic Champions as well as from an examination of the force and strength research that has been done. Because the goals are expressed as multiples of body weight they are applicable to both heavyweight and lightweight rowers.

 

Table 1. Strength to Weight Factors for Men

 

	High School	U 23	Club	National	Olympic
Squat	1.0	1.3	1.4	1.7	1.9
Deadlift	1.0	1.3	1.4	1.7	1.9
Bench Pull	0.7	0.9	1.05	1.2	1.3

 

 

Table 2. Strength to Weight Factors for Women

 

 

	High School	U 23	Club	National	Olympic
Squat	0.8	1.0	1.25	1.4	1.6
Deadlift	0.8	1.0	1.25	1.4	1.6
Bench Pull	0.6	0.8	0.95	1.1	1.2

 

 

 

Using the Tables

 To use the table take your body weight and multiply it by the appropriate factor. For instance if you were a 200 lb. Male club rower you should be able to bench pull 210 lbs. one time (200 lb. Bodyweight  x 1.05 = 210). These tables are appropriate for rowers aged 15-35. Strength normally decreases after age 35 and those under 15 should be focusing on technique and body stability instead of maximum strength. In a future article I will provide tables for rowers over age 35.

 If you currently are able to meet these goals you can focus your training on other areas. If you can’t meet these goals strength may be one of the things holding back your performance. Here are some pointers to help you reach your goals:

 

1. Take a Long Term Approach to Strength Development

  Don’t try to achieve these goals overnight. It may take several years for you to reach the strength goal at each competitive level. Notice how the strength level of Olympic rowers is twice that of the high school rower. The average age of Olympic rowers is 26-28 years old. This gives the high school rower about 10 years to double their strength. Rapid increases in strength are possible but won’t likely be maintained from year to year.

 

2.  Keep Everything in Perspective

 Just because you haven’t achieved the strength goals that I have outlined there is no reason to panic and wildly change your program. Decreasing the amount of aerobic training or technical training so that you can spend more time in the weight room may help you reach your strength goal but it may not make you a better rower.  Look at all aspects of your performance before changing your program. Aerobic and technical training are far more important than strength is to your performance. If you feel that you are technically proficient and aerobically very fit then maybe you can decrease the time you spend on these things until your strength level improves. Otherwise work on the other things first.

 

3. Don’t Over Do it

 Keep strength training sessions short. Sessions that last longer than 45-60 minutes often lead to overtraining. Shorter more frequent training sessions cause greater strength increases than long infrequent sessions. Try to fit in 3-5, 45 minute sessions each week.

 

4. Focus on Strength not Strength Endurance

 Until you have adequate strength, strength endurance training should be eliminated from the program. Strength increases do not occur with the high repetition, low resistance  training common in strength endurance programs. Strength endurance training without adequate strength only means you are getting better at being weak.

Testing Your Strength

A couple of issues ago I discussed strength goals and how much strength is necessary for a rower. Now that you know how strong you need to be let’s turn our attention to figuring out how strong you are.

 There are two types of strength testing. Maximal strength testing, often called 1RM, measures the maximum amount of weight that can be lifted one time. Submaximal repetition testing involves a lighter weight, more repetition and a formula to estimate maximum strength.

  1RM Tests

 Maximum strength testing (1RM testing) can be a time consuming process. It will normally take anywhere from 20-40 minutes per exercise to do a true max test. The procedure is as follows:

 

• Warm up with a light weight that can easily be handled for 5-10 reps
• Rest 2 minutes
• Increase the weight by 10-20% and do a second warm up of  3-5 reps.
• Rest 2 minutes
• Increase the weight by another 10-20% and perform a final warm up of 2-3 reps
• Rest 3-4 minutes
• Increase the load by 5-10% and try one repetition
• Rest 3-4 minutes
• If the last attempt was successful increase the weight by 5% and try another one repetition. If it was not successful decrease the weight by 2.5-5% and try again.
• Repeat this process until only one repetition can be performed with proper technique. Always rest 3-4 minutes between attempts.

 

Ideally the 1RM will be found within five sets of finishing the warm up. If it takes longer than this fatigue may affect the accuracy of the test. Normally this type of testing is accurate to within 5% of the true 1RM.

 

Estimated Tests

 Estimated tests have been developed as a time efficient alternative to 1RM testing. These tests use formulas to predict maximum strength. In most cases these tests are as accurate as the 1RM test. They lose their accuracy with athletes who train very close to their max for long periods at a time. The procedure is a s follows:

 

• Warm up with a light weight that can easily be handled for 5-10 reps
• Rest 2 minutes
• Increase the weight by 10-20% and do as many reps as possible. You should reach failure between 2 and 10 reps.
• Look up the weight you lifted and the number of reps you did on the chart. Where the two meet is your 1RM

 

If you do more than 10 reps take a 10 minute rest, increase the weight by another 10-20% and try again.

 

 

Test Exercises

 

If you recall from the How Strong is Strong Enough article a couple of issues ago, I provided strength to weight factors for three lifts, the squat, deadlift, and bench pull. These three exercises are used because they test all the muscles used in rowing, require a minimal amount of equipment, and are very easy to standardize. They are also exercises that should be included in most rowers training programs.

The Squat

 The bar is placed across the back. The hands should be as close together as possible, the elbows point towards the floor and feet are slightly wider than shoulder width apart. Back one step out of the rack, take a deep breath and contract your abs to stabilize your trunk and descend slowly into a squat position. Once you reach the bottom drive with your legs and return to a standing position.

 Squat depth needs to be consistent from test to test otherwise you won’t know if you are improving. The test should be done using a full squat (deeper than the half squat depicted in the diagram but I don’t have a drawing of the full squat). A good guideline for depth is your hamstrings should touch your calves. There is a misconception that going below 90 degrees will cause knee problems. There is no research to back up this contention only speculation. Strength improvements are specific to the range of motion that you use. As a rower it is vital that you achieve similar knee angles in the squat that you would achieve in the boat. If you don’t squat all the way to the bottom you won’t increase your strength at the catch.

Bench Pull

 Lie face down on a high bench. When you grasp the bar arms should be straight, hands shoulder width apart. Keeping the head, upper body, and legs flat on the bench, pull the weight up until it touches the bottom of the bench. If you don’t have a high bench at your facility you can make one by taking a flat bench and putting it on a couple of aerobics steps. If you do this, make sure the bench is stable and balanced before you start lifting. Try to use the same or bench each time you test. The thickness of the bench will affect how far you have to pull and the test results.

 

Deadlift

Stand in front of a bar feet shoulder width apart.  Squat down and grasp the bar with an overhand grip i.e. palms towards you. Keeping the back flat, take a deep breath, tighten your abs and stand up with the weight using your legs to start the movement. It is very important to feel the legs working in this exercise. If you straighten the legs too soon, in a movement similar to shooting your slide, it becomes a back lift and could cause injury.

 If you are not familiar with these lifts, take a few weeks to practice technique before attempting any sort of test.

 Regular testing is part of any good training program. It helps you establish goals and provides concrete evidence about the effectiveness of the program. Strength tests need to be repeated every training cycle or 4-6 weeks.

 

 Strength Prediction Table

 Find the weight you lifted in the left column. Find the number of reps you did with that weight across the top. Where the point where the two meet is your 1RM.

 

Reps	2	3	4	5	6	7	8	9	10
Weight
45	48	49	51	52	54	55	57	58	60
50	53	55	57	58	60	62	63	65	67
55	59	60	62	64	66	68	70	71	73
60	64	66	68	70	72	74	76	78	80
65	69	71	74	76	78	80	82	84	86
70	75	77	79	82	84	86	88	91	93
75	80	82	85	87	90	92	95	97	100
80	85	88	91	93	96	98	101	104	106
85	91	93	96	99	102	105	107	110	113
90	96	99	102	105	108	111	114	117	120
95	101	104	108	111	114	117	120	123	126
100	107	110	113	117	120	123	126	130	133
105	112	115	119	122	126	129	133	136	140
110	117	121	125	128	132	135	139	143	146
115	123	126	130	134	138	142	145	149	153
120	128	132	136	140	144	148	152	156	160
125	133	137	142	146	150	154	158	162	166
130	139	143	147	151	156	160	164	169	173
135	144	148	153	157	162	166	171	175	180
140	149	154	158	163	168	172	177	182	186
145	155	159	164	169	174	178	183	188	193
150	160	165	170	175	180	185	190	195	200
155	165	170	175	181	186	191	196	201	206
160	171	176	181	186	192	197	202	208	213
165	176	181	187	192	198	203	209	214	219
170	181	187	192	198	204	209	215	220	226
175	187	192	198	204	210	215	221	227	233
180	192	198	204	210	216	222	228	233	239
185	197	203	209	216	222	228	234	240	246
190	203	209	215	221	228	234	240	246	253
195	208	214	221	227	234	240	246	253	259
200	213	220	226	233	240	246	253	259	266
205	219	225	232	239	246	252	259	266	273
Weight	2	3	4	5	6	7	8	9	10
210	224	231	238	245	252	259	265	272	279
215	229	236	243	250	258	265	272	279	286
220	235	242	249	256	264	271	278	285	293
225	240	247	255	262	270	277	284	292	299
230	245	253	260	268	276	283	291	298	306
235	251	258	266	274	282	289	297	305	313
240	256	264	272	280	288	295	303	311	319
245	261	269	277	285	294	302	310	318	326
250	267	275	283	291	300	308	316	324	333
255	272	280	289	297	305	314	322	331	339
260	277	286	294	303	311	320	329	337	346
265	282	291	300	309	317	326	335	344	352
270	288	297	306	315	323	332	341	350	359
275	293	302	311	320	329	339	348	357	366
280	298	308	317	326	335	345	354	363	372
285	304	313	323	332	341	351	360	370	379
290	309	319	328	338	347	357	367	376	386
295	314	324	334	344	353	363	373	383	392
300	320	330	340	350	359	369	379	389	399
305	325	335	345	355	365	375	386	396	406
310	330	341	351	361	371	382	392	402	412
315	336	346	357	367	377	388	398	409	419
320	341	352	362	373	383	394	404	415	426
325	346	357	368	379	389	400	411	422	432
330	352	363	374	384	395	406	417	428	439
335	357	368	379	390	401	412	423	434	446
340	362	374	385	396	407	419	430	441	452
345	368	379	391	402	413	425	436	447	459
350	373	385	396	408	419	431	442	454	466
355	378	390	402	414	425	437	449	460	472
360	384	396	408	419	431	443	455	467	479
365	389	401	413	425	437	449	461	473	485
370	394	407	419	431	443	455	468	480	492
375	400	412	425	437	449	462	474	486	499
380	405	418	430	443	455	468	480	493	505
385	410	423	436	449	461	474	487	499	512
390	416	429	441	454	467	480	493	506	519
395	421	434	447	460	473	486	499	512	525
400	426	440	453	466	479	492	506	519	532
405	432	445	458	472	485	499	512	525	539
Weight	2	3	4	5	6	7	8	9	10
410	437	451	464	478	491	505	518	532	545
415	442	456	470	483	497	511	525	538	552
420	448	462	475	489	503	517	531	545	559
425	453	467	481	495	509	523	537	551	565
430	458	473	487	501	515	529	544	558	572
435	464	478	492	507	521	535	550	564	579
440	469	484	498	513	527	542	556	571	585
445	474	489	504	518	533	548	562	577	592
450	480	495	509	524	539	554	569	584	599